1748 2026
This is an AI modernization of An Enquiry Concerning Human Understanding into contemporary English. The original is available from Standard Ebooks. Also available as an epub.
David Hume published this book in 1748, at thirty-seven, after the failure of a much longer one. His Treatise of Human Nature had come out in 1739 and 1740 and, in his own words, fell dead-born from the press. He concluded that the fault was his — too long, too intricate, published too young — and rewrote its first part as the twelve short sections here, aimed at an ordinary educated reader rather than at philosophers. It worked. This is the version that was read, argued with, and eventually credited with waking Kant up.
Very little in it sounds old, and that is the difficulty. Hume writes a clean, quick, often funny English that a modern reader glides through, and several of his terms are ordinary words doing technical work. A matter of fact is not something prosaic; it is a truth about the world that can only be known by experience, as opposed to a relation of ideas like a sum in arithmetic, and the distinction between those two is the hinge the whole book turns on. An impression is a sensation as you have it, an idea the fainter copy of it you have afterwards. Custom means habit, and it is doing more work than any other word in the book.
What he argues is that we have no rational grounds whatever for expecting the future to resemble the past. Every piece of reasoning about cause and effect rests on that expectation, and no argument can establish it without assuming it. We do it anyway, because we are creatures of habit rather than of reason, and Hume's point is not that we should stop but that we should be clear about what we are doing. Section Four is where it happens, and the sun failing to rise tomorrow is the example he uses.
Two sections caused trouble and both are here entire. Section Ten argues that no testimony has ever been, or could be, strong enough to establish a miracle, and closes by observing that the Christian religion cannot be believed by any reasonable person without one. Section Eleven puts an argument against divine providence into the mouth of a friend speaking in the person of Epicurus, a piece of deniability Hume built in deliberately. He was refused professorships at Edinburgh and Glasgow on the strength of writing like this, and he never held an academic post.
His famous sentences are already plain — custom is the great guide of human life, a wise man proportions his belief to the evidence — and where a sentence was already clear this edition has left it alone.
Section One: The Two Kinds of Philosophy
Section Two: Where Our Ideas Come From
Section Three: How Ideas Link Up
Section Four: Sceptical Doubts About How the Mind Works
Section Five: A Sceptical Solution to These Doubts
Section Seven: The Idea of Necessary Connection
Section Eight: Liberty and Necessity
Section Nine: The Reasoning of Animals
Section Eleven: A Particular Providence and a Future State
Section Twelve: The Academic, or Sceptical, Philosophy
Moral philosophy — the study of human nature — can be done in two quite different ways. Each has its own merit, and each can entertain, instruct, and improve us.
The first sort treats a human being as made for action, and as guided by taste and feeling: pursuing this, avoiding that, according to what things seem to be worth and the light they happen to be seen in. Since virtue is agreed to be the most valuable thing there is, philosophers of this sort paint her in the most attractive colours they can find. They borrow whatever help poetry and eloquence can give them, they write in an easy and obvious style calculated to please the imagination and engage the affections, and they take their material from ordinary life — the striking case, the memorable instance, opposite characters set side by side for the contrast. They lure us onto the path of virtue with the prospect of glory and happiness, and then keep us on it with sound maxims and famous examples. They make us feel the difference between vice and virtue. They stir our feelings and then govern them; and if they can bend our hearts towards honesty and real honour, they consider their whole life's work done.
The second sort of philosopher treats a human being as a reasoning creature rather than an acting one, and works on his understanding rather than on his manners. They regard human nature as something to be investigated, and they examine it under a narrow lens, looking for the principles that regulate our understanding, arouse our feelings, and make us approve or condemn a particular object or action or piece of behaviour. They think it a disgrace to learning that philosophy still has not settled, beyond argument, the foundations of morals, of reasoning, and of criticism — that it goes on for ever talking about truth and falsehood, vice and virtue, beauty and ugliness, without being able to say where these distinctions come from. They are not put off by how hard the task is. They work from particular instances up to general principles, and from those to still more general ones, and they refuse to stop until they reach the ultimate principles beyond which human curiosity cannot go in any science at all. Their speculations look abstract, and to the ordinary reader unintelligible; but it is the approval of the learned they are after, and they think a whole lifetime's labour repaid if they can turn up a few hidden truths for the instruction of posterity.
The easy and obvious philosophy will always be preferred by most people to the exact and difficult one — that much is certain — and many will recommend it not merely as more agreeable but as more useful. It has more to do with ordinary life. It shapes the heart and the affections; it works on the springs that actually move people, and so reforms their conduct and brings them nearer to the model it describes. The difficult philosophy, on the other hand, rests on a cast of mind that cannot cope with business and action, and it evaporates the moment the philosopher steps out of the shade into daylight. Its principles do not keep any real hold on our behaviour. The feelings of the heart, the agitation of the passions, the sheer force of our affections scatter all its conclusions and reduce the profound philosopher to an ordinary man.
It has to be admitted, too, that the most lasting fame, and the fairest, has gone to the easy philosophy. Abstract reasoners have so far enjoyed only a passing reputation, granted by the whim or ignorance of their own age, and have not been able to keep it with a more even-handed posterity. It is easy for a profound philosopher to make a mistake in his subtle reasoning, and one mistake is the inevitable parent of another as he pushes his consequences along, undeterred by how strange a conclusion looks or how flatly it contradicts what everyone believes. But a philosopher whose only aim is to present the common sense of mankind in more attractive colours, if he happens into an error, goes no further: he appeals again to common sense and to the natural feelings of the mind, comes back onto the right road, and keeps himself clear of dangerous illusions. Cicero's reputation flourishes today; Aristotle's has entirely collapsed. La Bruyère crosses the Channel and holds his reputation abroad, while Malebranche's glory is confined to his own country and his own generation. And Addison, perhaps, will still be read with pleasure when Locke has been completely forgotten.
The philosopher and nothing else is a figure the world has never much cared for, on the assumption that he contributes nothing to either the profit or the pleasure of society — living apart from other people, and wrapped up in principles and notions equally far beyond them. On the other hand, the ignorant man and nothing else is despised still more; and in an age and a country where the sciences flourish, nothing marks out a coarse mind so surely as having no appetite at all for those splendid entertainments. The ideal character is supposed to lie between the two extremes: equally at home with books, with company, and with business; bringing to conversation the discernment and delicacy that reading gives, and to business the honesty and precision that follow from a sound philosophy. And nothing does more to spread and cultivate a character of that kind than writing in the easy style — writing that does not draw too far away from life, that needs no deep study or retreat to be understood, and that sends the student back among his fellow creatures full of fine sentiments and sensible maxims fitted to every situation life can produce. Writing like that makes virtue attractive, science agreeable, company instructive, and solitude entertaining.
A human being is a reasoning creature, and takes his proper nourishment from knowledge — but the bounds of human understanding are so narrow that not much satisfaction can be expected from this quarter, either from how far our knowledge extends or from how secure it is. A human being is a sociable creature no less than a reasoning one — but he cannot always have company that is pleasant and amusing, or keep his appetite for it when he has. A human being is an active creature too, and both that disposition and the plain necessities of life oblige him to work — but the mind needs some relaxation, and cannot be held indefinitely to care and industry. So nature seems to have marked out a mixed sort of life as the one that suits us, and to have quietly warned us not to let any of these tendencies draw too hard, in case it disqualifies us for the others. Indulge your passion for knowledge, she says, but let your knowledge be human, with some direct bearing on action and on society. Abstruse thought and deep research I forbid, and I shall punish severely — with the brooding melancholy they bring on, with the endless uncertainty they leave you in, and with the cold reception your supposed discoveries will get when you announce them. Be a philosopher; but amidst all your philosophy, be still a man.
If most people were content to prefer the easy philosophy to the abstract one without heaping blame or contempt on the second, it might be as well to go along with the general opinion and let everybody enjoy his own taste unopposed. But the thing is often carried further, as far as rejecting all deep reasoning outright — everything commonly called metaphysics — so it is worth considering what can reasonably be said in its defence.
We may begin by noticing one considerable advantage of the exact and abstract philosophy: how useful it is to the easy and humane sort, which without it can never get its sentiments or its maxims or its reasonings exact enough. All literature is nothing but pictures of human life in various attitudes and situations, inspiring us with different feelings — praise or blame, admiration or ridicule — according to the qualities of whatever it sets before us. An artist will obviously be better at that job if, besides a fine taste and a quick grasp, he has exact knowledge of the internal machinery: how the mind works, how the passions operate, and what the different kinds of feeling are that mark off vice from virtue. However unpleasant this inward search may look, it is to some extent necessary for anyone who wants to describe the outward appearances of life and manners successfully. The anatomist puts the most hideous and disagreeable objects in front of your eyes; but his science is what allows the painter to draw a Venus or a Helen. The painter may use the richest colours he has and give his figures the most graceful attitudes, but he still has to attend to the structure underneath — where the muscles lie, how the bones are put together, the shape and function of every part. Accuracy always helps beauty, and sound reasoning always helps delicate feeling. There is nothing to be gained by exalting one at the other's expense.
Notice as well that in every art and profession, including those most bound up with practical life, a habit of accuracy — however it was acquired — carries the whole business closer to perfection and makes it more useful to society. And though an individual philosopher may live far from affairs, the philosophical spirit, if enough people cultivate it carefully, must gradually spread through the whole society and lend the same exactness to every trade and calling. The politician acquires more foresight and subtlety in dividing and balancing power; the lawyer, better method and finer principles in his arguments; the general, more regularity in his discipline and more caution in his plans. Modern governments are steadier than ancient ones, and modern philosophy more exact, and both have improved by the same steps — and probably will go on improving.
Even if nothing came of these studies beyond the satisfaction of a harmless curiosity, that would still not deserve contempt: it is one more of the few safe and inoffensive pleasures allotted to the human race. The sweetest and least harmful road through life runs through learning; and anyone who can clear an obstruction from it, or open up a new view along it, deserves to be counted a benefactor. And though this sort of research looks painful and exhausting, some minds are like some bodies — so vigorously healthy that they need hard exercise, and take pleasure in what most people would find a burden. Obscurity is certainly painful, to the mind as much as to the eye; but bringing light out of obscurity, however much labour it costs, is bound to be a delight.
Still, the obscurity of the deep and abstract philosophy is objected to on more than the grounds of being painful and exhausting. It is said to be the inevitable source of uncertainty and error. And here lies the fairest and most plausible objection to a great deal of metaphysics: that it is not properly a science at all, but arises either from the fruitless efforts of human vanity trying to force its way into subjects the understanding simply cannot reach, or else from the cunning of popular superstitions, which cannot defend themselves in open country and so throw up these tangling brambles to cover their weakness. Chased off the plain, the robbers escape into the forest, and lie in wait to break in at any unguarded approach to the mind and overwhelm it with religious fears and prejudices. The toughest opponent, if he relaxes his watch for a moment, is overrun. And many people, out of cowardice and folly, throw the gates open to the enemy and receive them with reverence and submission, as their rightful sovereigns.
But is that a good reason for philosophers to abandon such enquiries and leave superstition in undisturbed possession of her hiding place? Should we not draw exactly the opposite conclusion, and see that the war has to be carried into the enemy's most secret recesses? It is no use hoping that men, after enough disappointments, will finally give up these airy sciences and recognise the proper limits of human reason. Quite apart from the fact that a good many people have too keen an interest in bringing such topics up for ever — quite apart from that, I say, blind despair can never be a reasonable motive in any science, because however badly earlier attempts have gone, there is always room to hope that the industry or luck or sharper judgement of a later generation will reach discoveries the earlier ones missed. Every adventurous mind will still leap at the difficult prize, stimulated rather than discouraged by his predecessors' failures, and hoping that the glory of so hard an adventure has been reserved for him alone. The only way to free learning from these abstruse questions at a stroke is to enquire seriously into the nature of human understanding, and to show, from an exact analysis of its powers and its capacity, that it is not remotely fitted for such remote and difficult subjects. We must put up with this fatigue in order to be at ease ever afterwards. We must cultivate true metaphysics carefully in order to destroy the false and adulterated kind. Laziness protects some people from this deceitful philosophy, but in others curiosity outweighs it; and the despair that prevails at some moments may give way later to confident hopes. Exact and sound reasoning is the only universal remedy, suited to all persons and all temperaments, and the only thing capable of overturning that abstruse philosophy and metaphysical jargon which, mixed up with popular superstition, becomes practically impenetrable to careless reasoners and takes on the air of science and wisdom.
Besides the advantage of rejecting, after deliberate enquiry, the most uncertain and disagreeable part of learning, there are many positive advantages in an exact examination of the powers and faculties of human nature. It is a remarkable thing about the operations of the mind that although they are more intimately present to us than anything else, the moment they become the object of reflection they seem to be wrapped in obscurity, and the eye cannot easily find the lines and boundaries that separate one from another. The objects are too fine to stay long in the same aspect or position, and have to be caught in an instant by a sharpness of perception that comes partly from nature and is improved by habit and reflection. So it is no small part of science simply to know the different operations of the mind, to separate them from one another, to sort them under their proper heads, and to correct the apparent disorder they lie in when we turn our attention on them. This work of ordering and distinguishing has no particular merit when it is done on external bodies, the objects of our senses; but directed at the operations of the mind, its value rises in proportion to the difficulty and labour of doing it. And if we can get no further than this mental geography — this mapping of the mind's distinct parts and powers — it is at least a satisfaction to have got that far. The more obvious this science may look, and it is nothing of the kind, the more contemptible it must be for anyone with pretensions to learning to know nothing about it.
Nor can there be any real suspicion that this science is uncertain and fanciful, unless we take up a scepticism that destroys all speculation and even all action. It cannot be doubted that the mind has several powers and faculties; that these powers are distinct from each other; that what is genuinely distinct to immediate perception can be distinguished by reflection; and therefore that there is truth and falsehood in propositions on this subject — a truth and falsehood that lie within the reach of human understanding. There are plenty of obvious distinctions of this kind, such as the one between the will and the understanding, or between the imagination and the passions, which every human creature grasps; and the finer, more philosophical distinctions are no less real and certain, only harder to make out. Some successes in these enquiries, particularly recent ones, may give us a fairer idea of how certain and solid this branch of learning is. And are we going to think it worth a philosopher's labour to give us a true system of the planets, and settle the position and order of those distant bodies, while we make a point of overlooking the people who have so successfully mapped the parts of the mind, which concern us far more nearly?
May we not hope, though, that philosophy, if it is cultivated carefully and encouraged by public attention, can carry its enquiries further still, and discover at least something of the hidden springs and principles that drive the human mind in its operations? Astronomers were long content to prove from the phenomena the true motions, order and size of the heavenly bodies — until at last a philosopher arose who seems, by the most fortunate reasoning, to have also settled the laws and forces that govern the revolutions of the planets. The same has been done in other parts of nature. And there is no reason to despair of equal success in our enquiries into the powers and economy of the mind, if they are pursued with equal ability and equal caution. Probably one operation and principle of the mind depends on another, which may in turn be resolved into something more general and universal still; and how far these researches can be carried, it will be hard for us to say exactly, either before a careful attempt or even after one. This much is certain: attempts of the kind are made every day, even by the most careless philosophers, and nothing is more necessary than to go into the enterprise with real care and attention — so that if it lies within the compass of human understanding it may at last be brought off, and if it does not, it may at any rate be rejected with some confidence. That last conclusion is certainly not the one we want, and should not be embraced too hastily. Think how much beauty and value we should have to subtract from this kind of philosophy if it were true. When moralists considered the vast number and variety of the actions that excite our approval or dislike, they have always looked for some common principle on which all this variety of feeling might depend. They have sometimes pushed the search too far, out of a passion for some one general principle; but they were surely not wrong to expect that all the vices and virtues could be justly resolved into some general principles. Critics and logicians and even politicians have attempted the same, and not entirely without success — though more time, greater accuracy and more determined application may bring these sciences closer to perfection yet. To throw up every claim of this kind at a stroke may fairly be called more rash, more hasty and more dogmatic than the boldest and most confident philosophy that ever tried to force its crude pronouncements on mankind.
And what if this reasoning about human nature does look abstract and hard to follow? That is no evidence at all that it is false. On the contrary, it seems impossible that whatever has so far escaped so many wise and profound philosophers should turn out to be easy and obvious. And whatever these researches cost us, we may think ourselves well enough repaid, in pleasure as much as in profit, if by that means we can add anything to what we know about subjects of such enormous importance.
Still, the abstractness of these speculations is no recommendation but a drawback, and the difficulty can perhaps be got over by care and skill and by avoiding all unnecessary detail. So in the enquiry that follows I have tried to throw some light on subjects from which uncertainty has hitherto frightened off the wise, and obscurity the ignorant. It will be a happy thing if we can unite the territories of the two kinds of philosophy, reconciling deep enquiry with clarity, and truth with novelty. And happier still if, reasoning in this easy way, we can undermine the foundations of an abstruse philosophy which so far seems to have served only as a shelter for superstition and a cover for absurdity and error.
Everyone will readily grant that there is a considerable difference between what goes on in the mind when a man feels the pain of scorching heat or the pleasure of comfortable warmth, and what goes on when he afterwards remembers that sensation, or looks forward to it in imagination. Memory and imagination can mimic or copy what the senses deliver, but they can never quite match the force and liveliness of the original. The most we say of them, even when they are working at full strength, is that they represent their object so vividly that we could almost say we feel it or see it. Unless the mind is deranged by illness or madness, they can never reach a pitch of liveliness that makes the two impossible to tell apart. All the colours of poetry, however splendid, can never paint natural objects so well that the description gets taken for a real landscape. The liveliest thought is still weaker than the dullest sensation.
The same distinction runs through everything else the mind does. A man in a fit of anger is moved in a quite different way from one who is merely thinking about that emotion. If you tell me somebody is in love, I understand you easily enough and form a fair idea of his situation — but I could never mistake that idea for the real disturbance and agitation of the passion itself. When we look back on our past feelings, our thought is a faithful mirror and copies its objects truly; but the colours it works in are faint and dull beside the ones our original perceptions came dressed in. It takes no fine discrimination or metaphysical head to see the difference.
So we can divide everything the mind perceives into two classes, marked off by their different degrees of force and liveliness. The weaker and less lively ones are usually called Thoughts or Ideas. The other class has no name in our language, or in most others — I suppose because there was never any need outside philosophy to group them under a general term. So let us take a small liberty and call them Impressions, using the word in a sense somewhat different from the usual one. By impression I mean all our livelier perceptions: hearing, seeing, feeling, loving, hating, desiring, willing. Impressions are distinguished from ideas, which are the fainter perceptions we are aware of when we reflect on any of the sensations or movements just mentioned.
At first glance nothing seems less bounded than human thought. It escapes not only every human power and authority but even the limits of nature and reality. Assembling monsters, joining together shapes and appearances that do not belong together, costs the imagination no more effort than conceiving the most ordinary object. And while the body is confined to one planet, which it creeps about with pain and difficulty, thought can carry us in an instant to the remotest regions of the universe — or beyond the universe, into the boundless chaos where nature is supposed to lie in total confusion. What has never been seen or heard of can still be conceived, and nothing at all is beyond the power of thought except what involves a flat contradiction.
But though our thought seems to have this unbounded freedom, a closer look shows that it is really confined within very narrow limits, and that all this creative power of the mind comes to nothing more than a capacity for compounding, transposing, enlarging, or shrinking the materials the senses and experience have supplied. When we think of a golden mountain, we are only joining two ideas we already had, gold and mountain. We can conceive a virtuous horse, because from our own feelings we can conceive virtue, and we can attach that to the shape of an animal we know. In short, all the raw material of thinking comes from what we feel, outwardly or inwardly; the mixing and arranging of it is the only part that belongs to the mind. Or to put it in the language of philosophy: all our ideas, our fainter perceptions, are copies of our impressions, the livelier ones.
Two arguments should be enough to prove this. First: when we take apart our thoughts or ideas, however complex or lofty, we always find that they resolve into simple ideas copied from some earlier feeling. Even the ideas that look furthest from such an origin turn out, on closer inspection, to have come from it. The idea of God — an infinitely intelligent, wise and good Being — arises from reflecting on the operations of our own mind and enlarging those qualities of goodness and wisdom without limit. We can push this enquiry as far as we like, and we shall always find that every idea we examine is copied from a matching impression. Anyone who wants to deny that this holds universally has one easy way to refute it: produce the idea that in his opinion did not come from that source. It would then be up to us, if we wanted to keep our doctrine, to produce the impression that corresponds to it.
Second: if it happens, through some defect in the organ, that a man cannot have a certain kind of sensation, we always find he cannot have the corresponding ideas either. A blind man can form no notion of colours, a deaf man none of sounds. Restore the missing sense, and by opening this new entrance for his sensations you open one for the ideas as well, and he has no trouble conceiving those objects. It is the same if the object that would produce the sensation has simply never reached the organ. A Laplander or an African has no notion of the taste of wine. There are few if any cases of a comparable gap in the mind — a person who has never felt, or is entirely incapable of, some feeling or passion belonging to his species — but the same thing happens to a lesser degree. A mild-mannered man can form no idea of settled revenge or cruelty, and a selfish heart cannot easily conceive the heights of friendship and generosity. It is readily granted that other beings may have many senses we can form no conception of, because the ideas of them have never been introduced to us in the only way an idea can get into the mind: by actually feeling the sensation.
There is, however, one contrary case, which may show that it is not absolutely impossible for an idea to arise without the matching impression. It will readily be granted, I think, that the various distinct ideas of colour that come in by the eye, or of sound that come in by the ear, really are different from one another, resembling though they are. Now if that is true of different colours, it must be equally true of the different shades of a single colour, and each shade produces a distinct idea independent of the rest. Deny that, and you could run one colour by imperceptible gradations into the colour furthest from it — and if you refuse to allow that any of the steps differ, you cannot without absurdity deny that the two ends are the same. So suppose a man has had his sight for thirty years and has become perfectly familiar with colours of every kind except one particular shade of blue, which he has never happened to meet with. Lay out before him all the shades of that colour except the one, descending gradually from the deepest to the lightest. Plainly he will notice a gap where the missing shade should be, and will be aware that the distance between neighbouring colours is greater there than anywhere else. Now I ask: is it possible for him, out of his own imagination, to make up the deficiency and raise up the idea of that particular shade, although it has never been delivered to him by his senses? Few people, I think, will say he cannot — and that will serve as a proof that simple ideas are not always, in every single instance, derived from the matching impression. But the case is so peculiar that it is hardly worth noticing, and does not deserve to make us change our general rule for its sake alone.
So here is a proposition that not only looks simple and intelligible in itself, but which, if it were properly used, might make every dispute equally intelligible and banish the jargon that has for so long occupied metaphysical reasoning and brought it into disrepute. All ideas, and abstract ones especially, are naturally faint and obscure. The mind gets only a slender grip on them, they are easily confused with other ideas that resemble them, and once we have used a term often enough — even without any distinct meaning — we tend to assume there must be a definite idea attached to it. Impressions, on the other hand — all sensations, whether outward or inward — are strong and vivid. The boundaries between them are much more exactly fixed, and it is not easy to go wrong about them. So whenever we suspect that a philosophical term is being used with no meaning or idea behind it, which happens far too often, we need only ask: from what impression is that supposed idea derived? And if none can be produced, that confirms the suspicion. By bringing ideas into so clear a light, we may reasonably hope to settle any dispute that arises about what they are and whether they are real.
Clearly there is some principle connecting the mind's different thoughts, so that when they present themselves to memory or imagination they introduce one another with a certain method and regularity. In our more serious thinking and talking this is obvious enough: any stray thought that breaks in on the regular chain of ideas is noticed at once and thrown out. And even in our wildest and most wandering daydreams — even in our dreams — we shall find, if we stop to consider, that the imagination was not running entirely at random, but that some connection was maintained among the ideas that followed one another. Take down the loosest and freest conversation and you will immediately see something linking it across all its turns. Or where that is missing, the person who snapped the thread could still tell you that a train of thought had been quietly running in his mind, leading him step by step away from the subject. And in different languages, even where we cannot suspect the slightest connection or contact between them, we find that the words for the most complex ideas still correspond fairly closely — which proves that the simple ideas making up the complex ones were bound together by some universal principle with the same hold on everybody.
That different ideas are connected is too obvious to be missed, but I cannot find that any philosopher has tried to list or classify all the principles of association, though the subject seems worth some curiosity. There appear to me to be only three ways ideas connect: by Resemblance, by Contiguity in time or place, and by Cause or Effect.
That these do connect ideas will hardly be doubted. A picture naturally leads our thoughts to what it is a picture of; mentioning one room in a building naturally starts a question about the others; and if we think of a wound we can scarcely help thinking of the pain that follows. But that the list is complete, and that there are no other principles of association, may be hard to prove to a reader's satisfaction, or even to one's own. All we can do in a case like this is run through a number of instances and examine carefully what binds the different thoughts together, never stopping until we have made the principle as general as it will go. The more instances we examine, and the more care we take, the more confident we shall be that the list we end up with is complete.
Everything human reason can enquire into falls naturally into two kinds: Relations of Ideas and Matters of Fact. Of the first kind are geometry, algebra and arithmetic — in short, every statement that is certain either immediately or by proof. That the square of the hypotenuse is equal to the square of the two sides is a proposition expressing a relation between those figures. That three times five is equal to the half of thirty expresses a relation between those numbers. Propositions of this kind can be discovered by thought alone, without depending on anything that exists anywhere in the universe. If there had never been a circle or a triangle in nature, the truths Euclid proved would keep their certainty and their evidence for ever.
Matters of fact — the second thing human reason enquires into — are not established in that way, and our evidence for them, however strong, is not of the same kind. The contrary of every matter of fact is still possible, because it never involves a contradiction and the mind conceives it just as easily and clearly as if it agreed perfectly with reality. (A matter of fact, in the sense used throughout this book, is a claim about how the world actually stands — one that could have been otherwise, and that no amount of reasoning alone will settle.) That the sun will not rise tomorrow is a perfectly intelligible proposition and involves no more contradiction than the statement that it will rise. So it would be useless to try to prove it false. If it were provably false, it would involve a contradiction, and the mind could never conceive it clearly.
It may be worth some curiosity, then, to ask what sort of evidence it is that assures us of any real existence or matter of fact beyond what our senses are reporting now and what our memory has recorded. This part of philosophy has been little worked on, by ancients or moderns alike, so our doubts and mistakes in pursuing so important an enquiry may be the more excusable — we are marching down difficult roads with no guide. They may even do some good, by arousing curiosity and destroying the unquestioning confidence that is the ruin of all reasoning and free enquiry. Finding defects in the received philosophy, if there are any, will not discourage anybody, I imagine, but do what such discoveries usually do: provoke an attempt at something fuller and more satisfactory than has yet been offered to the public.
All reasoning about matters of fact seems to be founded on the relation of Cause and Effect. That relation is the only thing that lets us get beyond the evidence of memory and the senses. Ask a man why he believes some fact he is not currently observing — that his friend is in the country, say, or in France — and he will give you a reason, and the reason will be some other fact: a letter he has had, or his knowledge of the friend's earlier plans and promises. A man finding a watch, or any other machine, on a desert island would conclude that there had once been men there. All our reasoning about fact works the same way. And it is always assumed that there is a connection between the fact in front of us and the fact we infer from it. If nothing tied them together the inference would be entirely unfounded. Hearing an articulate voice and rational conversation in the dark assures us that somebody is there — why? Because those are the effects of the human make-up and closely connected with it. Dissect any other reasoning of this kind and you will find it founded on cause and effect, the relation being either near or remote, direct or sideways-on. Heat and light are two effects of a fire standing side by side, and either may fairly be inferred from the other.
So if we want to be satisfied about the nature of the evidence that assures us of matters of fact, we must ask how we come to know about cause and effect in the first place.
I shall venture a general proposition that admits of no exception: knowledge of this relation is never, in any single case, arrived at by reasoning in advance of experience. It comes entirely from experience — from finding that particular objects are constantly conjoined with one another. Present an object to a man of the strongest natural reason and ability; if the object is entirely new to him, no amount of examining the qualities he can see and touch will reveal any of its causes or effects. Adam, even supposing his rational faculties perfect from the first moment, could not have inferred from the fluidity and transparency of water that it would drown him, or from the light and warmth of fire that it would burn him. No object ever reveals, through the qualities that appear to the senses, either the causes that produced it or the effects that will follow from it; and reason, without help from experience, can never draw any conclusion about real existence and matter of fact.
This proposition — that causes and effects are discoverable, not by reason but by experience — will readily be granted for objects we can remember being entirely unfamiliar with, since we must be conscious of how completely unable we then were to say what would come of them. Show two smooth pieces of marble to a man with no trace of physics in him, and he will never work out that they will stick together so firmly that great force is needed to pull them straight apart, while they yield to the slightest sideways push. Events that bear little resemblance to nature's ordinary course are also readily admitted to be known only by experience; nobody imagines that the explosion of gunpowder, or the attraction of a magnet, could ever have been worked out by reasoning in advance. In the same way, where an effect is thought to depend on intricate machinery or a hidden structure of parts, we have no trouble crediting all our knowledge of it to experience. Who is going to claim that he can give the final reason why milk or bread is proper nourishment for a man and not for a lion or a tiger?
But the same truth may not look as obvious for events that have been familiar to us since we first appeared in the world, that closely resemble the whole course of nature, and that seem to depend on the simple qualities of objects with no hidden structure behind them. We are inclined to imagine that we could have discovered such effects by reason alone, without experience. We fancy that if we were dropped into this world all at once we could have inferred straight away that one billiard ball would pass on its motion to another when it struck it, and that there was no need to wait and see before pronouncing on it with certainty. Such is the influence of custom that where it is strongest it not only covers up our natural ignorance but hides itself as well, and seems not to be operating at all — precisely because it is operating so completely.
But the following considerations should be enough to convince us that all the laws of nature, and everything bodies do without exception, are known only by experience. Suppose an object were put in front of us and we were required to say what effect would follow from it, without consulting past observation. How, I ask you, is the mind supposed to go about this? It has to invent or imagine some event and assign it to the object as its effect — and the invention is plainly quite arbitrary. The mind can never find the effect in the supposed cause, however closely it scrutinises. For the effect is entirely different from the cause and consequently can never be discovered in it. Motion in the second billiard ball is a quite distinct event from motion in the first, and there is nothing in the one to give the slightest hint of the other. A stone or a piece of metal raised into the air and let go immediately falls; but considering the matter in advance of experience, is there anything in that situation that suggests the idea of a downward motion rather than an upward one, or any other? And since the first imagining of a particular effect is arbitrary in all natural operations, as long as we do not consult experience, so we must think the same of the supposed tie or connection between cause and effect that binds them together and makes it impossible for any other effect to follow from that cause. When I see a billiard ball rolling in a straight line towards another, and even supposing motion in the second ball happens to occur to me as the result of their contact, may I not just as easily conceive a hundred different events following from that cause? May not both balls stay perfectly still? May not the first ball bounce straight back, or spring off the second in any line or direction at all? All these suppositions are consistent and conceivable. So why should we prefer one, when it is no more consistent or conceivable than the rest? No amount of reasoning in advance of experience will ever show us any ground for the preference.
In a word: every effect is a distinct event from its cause. It could not therefore have been discovered in the cause, and the first imagining of it, in advance of experience, must be entirely arbitrary. Even once it has occurred to us, joining it to the cause must seem equally arbitrary, since there are always plenty of other effects that must strike reason as just as consistent and just as natural. It is no use pretending, then, that we can settle any single event, or infer any cause or effect, without the help of observation and experience.
This shows us why no philosopher who is rational and modest has ever claimed to give the ultimate cause of any natural operation, or to display clearly the working of the power that produces any single effect in the universe. It is admitted that the most human reason can do is reduce the principles behind natural phenomena to a greater simplicity, and resolve many particular effects into a few general causes, by reasoning from analogy, experience and observation. But the causes of those general causes we shall never discover, however hard we try, and no particular explanation of them will ever satisfy us. These ultimate springs and principles are entirely closed off from human curiosity. Elasticity, gravity, cohesion, the passing on of motion by impact: these are probably the ultimate causes and principles we shall ever find in nature, and we may count ourselves lucky enough if careful enquiry and reasoning can trace particular phenomena back to them, or somewhere near them. The most perfect philosophy of the natural kind only postpones our ignorance a little; the most perfect philosophy of the moral or metaphysical kind perhaps only uncovers more of it. So the observation of human blindness and weakness is what all philosophy comes to, and it meets us at every turn however hard we try to dodge it.
Nor can geometry, brought in to help natural philosophy, ever repair this defect or lead us to knowledge of ultimate causes, for all the exactness of reasoning it is so justly famous for. Every branch of applied mathematics proceeds on the assumption that nature has established certain laws in her operations, and uses abstract reasoning either to help experience discover those laws or to work out how they apply in particular cases where some precise distance or quantity is involved. It is a law of motion, discovered by experience, that the force of a moving body is in the compound ratio of its mass and its velocity — and consequently that a small force may move the greatest obstacle or lift the greatest weight, if by some contrivance we can raise the velocity of that force enough to overmatch what it is working against. Geometry helps us apply this law by giving us the exact dimensions of all the parts and shapes that can go into a machine of any kind; but the discovery of the law itself is owed entirely to experience, and all the abstract reasoning in the world could never have brought us a step nearer it. When we reason in advance of experience, and consider an object or a cause simply as it appears to the mind, independently of all observation, it could never suggest to us the idea of some distinct object as its effect — much less show us the inseparable and unbreakable connection between them. A man would have to be very shrewd indeed to discover by reasoning that crystal is the effect of heat and ice the effect of cold, without having previously seen what heat and cold do.
But we have still not reached any tolerable answer to the question we began with. Every solution raises a new question as hard as the last, and leads us further on. When it is asked, "What is the nature of all our reasoning about matters of fact?" the proper answer seems to be that it is founded on the relation of cause and effect. When it is asked next, "What is the foundation of all our reasoning and conclusions about that relation?" the answer can be given in one word: experience. But if we go on sifting and ask, "What is the foundation of all conclusions drawn from experience?" that raises a new question, and one that may be harder to solve and to explain. Philosophers who give themselves airs of superior wisdom and self-sufficiency have a hard time of it when they meet inquisitive people, who push them out of every corner they retreat into and are certain to drive them at last into some awkward dilemma. The best way to avoid that embarrassment is to be modest in our claims, and even to point out the difficulty ourselves before anyone else raises it. That way we can make a sort of merit out of our own ignorance.
In this section I shall set myself an easy task and claim only to give a negative answer to the question raised. What I say is this: even after we have experience of cause and effect at work, the conclusions we draw from that experience are not founded on reasoning, or on any process of the understanding. That answer has to be both explained and defended.
It must be granted that nature has kept us at a great distance from all her secrets, and has given us knowledge only of a few surface qualities of things, while she hides from us the powers and principles on which everything those things do entirely depends. Our senses tell us the colour, weight and texture of bread; but neither sense nor reason can ever tell us what qualities make it fit to nourish and sustain a human body. Sight or touch gives us the idea of a body actually moving; but as to that remarkable force or power which would carry a moving body on for ever through a continual change of place, and which bodies never lose except by passing it on to others — of that we can form no conception whatever. Yet in spite of this ignorance of natural powers and principles, whenever we see the same perceptible qualities we always assume the same hidden powers behind them, and expect effects like the ones we have met with before. If a body of the same colour and texture as the bread we have eaten before is put in front of us, we have no hesitation in repeating the experiment, and confidently expect the same nourishment and support.
Now this is a movement of the mind whose foundation I should very much like to know. Everyone agrees that there is no known connection between the perceptible qualities and the hidden powers, and therefore that the mind is not led to any conclusion about their constant and regular conjunction by anything it knows of their nature. As for past Experience, it can be allowed to give direct and certain information only about the precise objects, and the precise stretch of time, that came under its notice. But why this experience should be stretched to future times, and to other objects which for all we know may only look similar — that is the main question I want to press. The bread I ate before nourished me; that is, a body with those perceptible qualities was, at that time, endowed with those hidden powers. But does it follow that other bread must nourish me at another time, and that like perceptible qualities must always carry like hidden powers with them? The consequence seems in no way necessary. At the very least it must be admitted that a consequence is being drawn here by the mind — that a step is being taken, a movement of thought, an inference, and that it needs explaining. These two propositions are a long way from being the same: "I have found that such an object has always been followed by such an effect," and "I foresee that other objects which look similar will be followed by similar effects." I will allow, if you like, that the second may fairly be inferred from the first; I know in fact that it always is inferred. But if you insist that the inference is made by a chain of reasoning, then I ask you to produce that reasoning. The connection between the two propositions is not self-evident. Something is needed in the middle to enable the mind to draw such an inference, if it really is drawn by reasoning and argument. What that middle term is, I confess, is beyond me — and the burden is on those who assert that it exists, and that it is the origin of all our conclusions about matters of fact, to produce it.
This negative argument must in time become entirely convincing, if plenty of penetrating and able philosophers turn their attention this way and none of them can ever find the connecting proposition or intermediate step that supports the understanding in this conclusion. But since the question is still new, not every reader will trust his own penetration far enough to conclude that an argument does not exist merely because it has escaped his search. So it may be necessary to attempt something harder, and to run through all the branches of human knowledge in an effort to show that none of them can supply such an argument.
All reasoning divides into two kinds: demonstrative reasoning, which concerns relations of ideas, and moral reasoning, which concerns matters of fact and existence. That there are no demonstrative arguments in this case seems obvious, since there is no contradiction in supposing that the course of nature may change, and that an object apparently like the ones we have met before may be followed by different or opposite effects. Can I not clearly and distinctly conceive that a body falling from the clouds, and in every other respect resembling snow, nevertheless tastes of salt or feels like fire? Is there any more intelligible proposition than that all the trees will flourish in December and January and wither in May and June? Now whatever is intelligible, and can be distinctly conceived, involves no contradiction, and can never be proved false by any demonstrative argument or by reasoning in advance of experience.
So if there are arguments that oblige us to trust past experience and make it the standard of our future judgement, they must be merely probable ones — arguments about matter of fact and real existence, by the division just made. But that there is no argument of that kind must be clear, if our account of that kind of reasoning is accepted as sound. We have said that all arguments about existence are founded on cause and effect; that our knowledge of that relation comes entirely from experience; and that all our conclusions from experience proceed on the assumption that the future will match the past. To try to prove that last assumption by probable arguments — arguments about existence — is plainly to argue in a circle, and to take for granted the very thing in question.
In reality all arguments from experience are founded on the resemblance we find among natural objects, which leads us to expect effects like the ones we have found to follow from such objects before. And though nobody but a fool or a madman would dispute the authority of experience or reject that great guide of human life, a philosopher may surely be allowed enough curiosity to examine the principle in human nature that gives experience this enormous authority and lets us profit from the resemblances nature has placed among different objects. From causes that appear similar we expect similar effects. That is the sum of all our conclusions from experience. Now it seems clear that if this conclusion were formed by reason, it would be as complete at the outset, on a single instance, as it is after any length of experience. But that is far from being the case. Nothing is so alike as two eggs; yet nobody expects the same taste in all of them on account of that apparent likeness. It is only after a long run of uniform trials of some kind that we come to rely firmly on a particular outcome. Where, then, is the piece of reasoning that draws one conclusion from a single instance and a quite different one from a hundred instances that differ from that single one in no way at all? I put the question as much to be informed as to raise difficulties. I cannot find, and cannot imagine, any such reasoning. But my mind remains open to instruction, if anyone will be good enough to supply it.
If it is said that from a number of uniform trials we infer a connection between the perceptible qualities and the hidden powers, that seems to me the same difficulty dressed in different words. The question comes back: on what argument is this inference founded? Where is the middle term, the connecting ideas, that join two propositions lying so far apart? It is admitted that the colour, texture and other perceptible qualities of bread do not by themselves appear to have any connection with the hidden powers of nourishment and support — otherwise we could infer those hidden powers from the first sight of those qualities, without any help from experience, which is contrary to what all philosophers think and contrary to plain fact. Here, then, is our natural state of ignorance about the powers of all objects. How does experience repair it? All it does is show us a number of uniform effects following from certain objects, and teach us that those particular objects, at that particular time, had such powers and forces. When a new object with similar perceptible qualities turns up, we expect similar powers and forces and look for a like effect. From a body of the same colour and texture as bread we expect the same nourishment. But this is surely a step or advance of the mind that needs explaining. When a man says, "I have found in every past instance that such perceptible qualities went with such hidden powers," and when he says, "Similar perceptible qualities will always go with similar hidden powers," he is not repeating himself; the two propositions are not the same in any respect. You say the second is an inference from the first. But you must admit the inference is not self-evident, and it is not demonstrative either. What kind of inference is it, then? To call it experimental is to beg the question, because every inference from experience assumes as its foundation that the future will resemble the past, and that similar powers will go with similar perceptible qualities. If there is any suspicion that the course of nature may change, and that the past may be no guide to the future, all experience becomes useless and can yield no inference or conclusion at all. So it is impossible that any argument from experience can prove this resemblance of past to future, since every such argument is founded on the assumption of it. Grant that the course of things has been as regular as you please up to now: that alone, without some new argument, does not prove that it will go on being regular. It is no use claiming to have learned the nature of bodies from your past experience. Their hidden nature, and consequently everything they do, may change without any change at all in their perceptible qualities. This does happen sometimes, with some objects. Why should it not happen always, and with all of them? What logic, what argument protects you against that supposition? My practice refutes my doubts, you say. But you have mistaken the point of my question. As a man who has to act, I am perfectly satisfied; but as a philosopher with a share of curiosity — I will not say of scepticism — I want to learn the foundation of this inference. No reading and no enquiry has yet removed the difficulty or satisfied me on a matter of such importance. Can I do better than lay the difficulty before the public, even if I have little hope of a solution? At least we shall become aware of our ignorance, if we do not add to our knowledge.
I admit that a man is guilty of unpardonable arrogance if he concludes that an argument does not exist merely because it has escaped his own search. I admit too that even if all the learned had spent several ages searching fruitlessly on some subject, it might still be rash to conclude that the subject must therefore be beyond all human comprehension. Even after examining every source of our knowledge and finding them all unfit for such a subject, there could still be a suspicion that the list was incomplete or the examination careless. But on the present subject there are some considerations that seem to me to remove any charge of arrogance or suspicion of error.
It is certain that the most ignorant and stupid peasants — infants too, and even animals — improve by experience, and learn the qualities of natural objects by watching the effects that follow from them. Once a child has felt pain from touching a candle flame, he will be careful not to put his hand near any candle, and will expect a similar effect from a cause that is similar in its perceptible qualities and appearance. So if you claim that the child's understanding is led to this conclusion by some process of argument or reasoning, I may fairly ask you to produce the argument, and you have no excuse for refusing so reasonable a demand. You cannot say the argument is abstruse and may have escaped your search, since you have just admitted it is within the capacity of an infant. If you hesitate a moment, then — or if after reflection you produce some intricate and profound argument — you have in effect given up the question, and admitted that it is not reasoning that makes us suppose the past resembles the future and expect similar effects from causes that look similar.
That is the proposition I meant to press in this section. If I am right, I do not claim to have made any great discovery. And if I am wrong, I must own myself a very slow scholar indeed, since I cannot now find an argument that was apparently perfectly familiar to me long before I was out of my cradle.
A passion for philosophy, like a passion for religion, seems open to one particular danger: that although it aims at correcting our behaviour and rooting out our vices, careless handling may let it do nothing but feed a tendency we already had, and drive the mind with more determined resolve towards the side that already draws too hard through the natural bias of our temperament. Certainly, while we aspire to the magnificent steadiness of the philosophic sage, and try to keep all our pleasures inside our own minds, we may in the end make our philosophy — like that of Epictetus and the other Stoics — into nothing but a more refined system of selfishness, and reason ourselves out of all virtue along with all social enjoyment. While we study the vanity of human life attentively, and turn all our thoughts to how empty and fleeting riches and honours are, we may all the while be flattering our natural laziness, which hates the bustle of the world and the drudgery of business and is looking for a reasonable-sounding excuse to indulge itself completely.
There is, though, one kind of philosophy that seems little exposed to this danger, because it chimes in with no disorderly passion of the mind and cannot mix itself with any natural inclination: the Academic, or Sceptical, philosophy. (The Academics are the sceptical school that grew out of Plato's Academy.) They are always talking about doubt and suspended judgement, about the danger of deciding in a hurry, about confining the enquiries of the understanding within very narrow bounds and giving up every speculation that falls outside ordinary life and practice. Nothing, then, could be more opposed than such a philosophy to the mind's lazy sprawl, its rash arrogance, its lofty pretensions and its superstitious credulity. Every passion is mortified by it except the love of truth, and that passion never is and never can be carried too far. It is surprising, then, that a philosophy which must in almost every case be harmless should be the object of so much groundless abuse. But perhaps the very thing that makes it so innocent is what chiefly exposes it to public hatred. Flattering no irregular passion, it wins few supporters; opposing so many vices and follies, it makes itself plenty of enemies, who brand it as libertine, profane and irreligious.
Nor need we fear that this philosophy, in trying to confine our enquiries to ordinary life, will ever undermine the reasoning of ordinary life and carry its doubts far enough to destroy action as well as speculation. Nature will always assert her rights and prevail in the end over any abstract reasoning whatever. Suppose we conclude, as in the last section, that in all reasoning from experience the mind takes a step that no argument supports: there is no danger that the reasoning almost all our knowledge depends on will ever be damaged by the discovery. If the mind is not moved by argument to take that step, it must be moved by some other principle of equal weight and authority — and that principle will keep its hold as long as human nature stays the same. What that principle is may well be worth the trouble of finding out.
Suppose a person with the strongest powers of reason and reflection were dropped suddenly into this world. He would certainly notice at once a continual succession of objects, one event following another; but he would not be able to make out anything more. He could not at first reach the idea of cause and effect by any reasoning, since the particular powers behind all natural operations never appear to the senses; and it is not reasonable to conclude, merely because one event precedes another on one occasion, that the first is the cause and the second the effect. Their occurring together may be arbitrary and accidental. There may be no reason to infer that one exists from the appearance of the other. In a word, without more experience such a person could never bring conjecture or reasoning to bear on any matter of fact, or be sure of anything beyond what was immediately present to his memory and senses.
Now suppose he has gained more experience, and has lived in the world long enough to have observed familiar objects or events constantly occurring together. What follows from that experience? He immediately infers the existence of one object from the appearance of the other. Yet for all his experience he has gained no idea or knowledge of the hidden power by which the one object produces the other; nor is it any process of reasoning that leads him to draw the inference. Still he finds himself determined to draw it — and even if he were convinced that his understanding had no part in the business, he would go on thinking in exactly the same way. Some other principle is making him form the conclusion.
That principle is Custom, or Habit. Whenever repeating some act produces a tendency to repeat it again, without being pushed by any reasoning or process of the understanding, we always say that the tendency is the effect of Custom. In using the word we do not claim to have given the ultimate reason for such a tendency. We are only pointing to a principle of human nature that everyone acknowledges and that is well known by its effects. Perhaps we can push our enquiries no further, or claim to give the cause of this cause, and must be content with it as the last principle we can name behind all our conclusions from experience. It is satisfaction enough that we can get this far, without complaining that our faculties are too narrow to take us further. And we are certainly putting forward a very intelligible proposition here, if not a true one, when we say that after the constant conjunction of two objects — heat and flame, for instance, or weight and solidity — custom alone determines us to expect the one when the other appears. This hypothesis even seems the only one that explains the difficulty of why we draw from a thousand instances an inference we cannot draw from one instance that differs from them in no respect at all. Reason is incapable of any such variation: the conclusions it draws from considering one circle are the same as it would form from surveying every circle in the universe. But no man who had seen only one body move after being struck by another could infer that every other body would move after a similar blow. So all inferences from experience are effects of custom, not of reasoning.
Custom, then, is the great guide of human life. It is that principle alone which makes our experience useful to us, and makes us expect a train of events in the future like the one that has appeared in the past.
Without the influence of custom we should be entirely ignorant of every matter of fact beyond what is immediately present to memory and the senses. We should never know how to fit means to ends, or how to use our natural powers to produce any effect. There would be an immediate end to all action, and to the greater part of speculation.
It is worth remarking here, though, that although our conclusions from experience carry us beyond memory and the senses, and assure us of facts that happened in the most distant places and the remotest ages, there must always be some fact present to the senses or memory to start from. A man who found the remains of grand buildings in a deserted country would conclude that it had once been settled by civilised inhabitants; but if nothing of the kind came before him, he could never form such an inference. We learn the events of former ages from history — but then we have to read the volumes that contain the information, and work our inferences back from one piece of testimony to another until we reach the eyewitnesses of those distant events. In a word, unless we start from some fact present to memory or the senses, our reasoning would be merely hypothetical, and however well the individual links held together, the whole chain of inferences would have nothing to hang from, nor could we ever reach knowledge of any real existence by it. If I ask why you believe some particular fact you are telling me, you must give me a reason, and the reason will be some other fact connected with it. But since you cannot go on that way for ever, you must end at last at some fact present to your memory or senses — or else admit that your belief has no foundation at all.
So what is the conclusion of the whole business? A simple one, though it must be admitted it is a good way from the usual theories of philosophy. All belief in matter of fact or real existence comes merely from some object present to the memory or senses, together with a customary conjunction between that object and some other. Or in other words: having found on many occasions that two kinds of object — flame and heat, snow and cold — have always gone together, then if flame or snow is presented to the senses again, the mind is carried by custom to expect heat or cold, and to believe that the quality does exist and will show itself on a closer approach. This belief is the necessary result of putting the mind in such a position. It is an operation of the soul which, when we are so placed, is as unavoidable as feeling love when we are done a kindness, or hatred when we are injured. All these operations are a kind of natural instinct, which no reasoning or process of thought can either produce or prevent.
At this point we might quite properly stop our philosophical researches. On most questions we can never take a single step further, and on all questions we must end here at last, however restlessly and curiously we enquire. But our curiosity will still be pardonable, perhaps even creditable, if it carries us on to further research, and makes us examine more closely the nature of this belief and of the customary conjunction it comes from. That way we may meet with some explanations and analogies that satisfy — at any rate those who love the abstract sciences and can enjoy speculations that keep a degree of doubt about them however carefully they are made. Readers of a different taste will find the rest of this section is not written for them, and the enquiries that follow can be understood perfectly well without it.
Nothing is freer than human imagination. Though it cannot go beyond the original stock of ideas supplied by the inner and outer senses, it has unlimited power to mix, combine, separate and divide those ideas into every variety of fiction and vision. It can invent a train of events with every appearance of reality, assign them a particular time and place, conceive them as actually existing, and paint them out to itself with every detail belonging to a historical fact that it believes with the greatest certainty. So where does the difference between such a fiction and a belief lie? Not merely in some special idea attached to the conception that commands our assent and missing from every acknowledged fiction. For since the mind has authority over all its ideas, it could attach this particular idea to any fiction it liked, and would therefore be able to believe whatever it pleased — which is contrary to what we find every day. We can join the head of a man to the body of a horse in our imagination; but it is not in our power to believe that such an animal has ever really existed.
It follows that the difference between fiction and belief lies in some sentiment or feeling attached to the second and not the first, which does not depend on the will and cannot be summoned at pleasure. It must be aroused by nature, like every other sentiment, and must arise from the particular situation the mind is in at that moment. Whenever an object is presented to the memory or senses, the force of custom immediately carries the imagination to conceive the object usually joined with it — and that conception comes with a feeling different from the loose daydreams of fancy. That is the whole nature of belief. Since there is no matter of fact we believe so firmly that we cannot conceive the contrary, there would be no difference between the conception we assent to and the one we reject, were it not for some feeling that marks one off from the other. If I see a billiard ball rolling towards another on a smooth table, I can easily conceive it stopping on contact. There is no contradiction in the idea; but it still feels very different from the conception in which I picture the impact and the passing on of the motion from one ball to the other.
If we tried to give a definition of this feeling, we should probably find the task very difficult if not impossible — much as if we tried to define the feeling of cold, or the passion of anger, to a creature who had never experienced them. Belief is the true and proper name of this feeling, and nobody is ever at a loss for what the word means, because every man is conscious of the feeling at every moment. It may not be out of place, though, to attempt a description of it, in the hope of arriving at some analogies that explain it better. What I say is that belief is nothing but a more vivid, lively, forcible, firm and steady conception of an object than the imagination alone can ever manage. This string of terms may look unphilosophical, but it is meant only to express the act of mind that makes realities — or what we take for realities — more present to us than fictions, gives them more weight in our thinking, and lets them exert more influence over the passions and the imagination. As long as we agree about the thing, there is no need to argue about the words.
The imagination has command over all its ideas and can join and mix and vary them in every possible way. It can conceive fictitious objects with all the circumstances of place and time. It can set them before our eyes, so to speak, in their true colours, exactly as they might have existed. But since it is impossible for imagination on its own ever to reach belief, plainly belief consists not in the particular nature or arrangement of the ideas but in the manner of conceiving them, and in how they feel to the mind. I confess it is impossible to explain this feeling, or manner of conception, perfectly. We can use words that come near it. But its true and proper name, as I said, is belief — a term everybody understands well enough in ordinary life. And in philosophy we can go no further than to assert that belief is something felt by the mind, which marks off the ideas of judgement from the fictions of the imagination. It gives them more weight and influence, makes them seem more important, presses them on the mind, and makes them the governing principle of what we do. At this moment, for instance, I hear the voice of somebody I know, and the sound seems to come from the next room. This impression on my senses immediately carries my thought to the person, and to everything around him. I picture them to myself as existing right now, with the same qualities and relations I knew them to have before. These ideas take a firmer hold on my mind than the idea of an enchanted castle. They feel quite different, and they have far greater influence of every kind, whether to give pleasure or pain, joy or sorrow.
So let us take in the whole scope of this doctrine, and grant that the feeling of belief is nothing but a conception more intense and steady than the one attending the mere fictions of imagination, and that this manner of conception arises from a customary conjunction of the object with something present to the memory or senses. On those assumptions it will not be hard, I think, to find other operations of the mind that work the same way, and to trace all these phenomena back to still more general principles.
We have already observed that nature has established connections among particular ideas, and that as soon as one idea occurs to us it introduces its partner and draws our attention towards it by a gentle, imperceptible movement. We reduced these principles of connection to three — Resemblance, Contiguity and Causation — which are the only bonds tying our thoughts together and producing the regular train of reflection or conversation that goes on, more or less, in everybody. Now a question arises here on which the solution of the present difficulty depends. Does it happen, in all these relations, that when one of the objects is presented to the senses or memory, the mind is not only carried to conceive its partner but reaches a steadier and stronger conception of it than it could otherwise have managed? That seems to be the case with the belief arising from cause and effect. And if it holds for the other relations too, it may be set down as a general law governing everything the mind does.
For a first experiment to that purpose, notice that when the picture of an absent friend appears, our idea of him is plainly enlivened by the resemblance, and every feeling the idea arouses, whether joy or sorrow, gains new force. Two things combine to produce this effect: a relation, and a present impression. Where the picture bears him no resemblance, or at any rate was not meant for him, it does not so much as carry our thought to him. And where the picture is absent as well as the person, then although the mind may pass from the thought of one to the thought of the other, it finds its idea weakened rather than enlivened by the transition. We take pleasure in looking at a friend's picture when it is in front of us; but once it is taken away, we would rather think about him directly than through the reflection of an image equally distant and equally dim.
The ceremonies of the Roman Catholic religion may be considered instances of the same thing. The devotees of that superstition usually plead, in excuse for the mummeries they are reproached with, that they feel the good effect of those outward motions and postures and actions in enlivening their devotion and quickening a fervour that would otherwise fade if it were directed entirely at distant and immaterial objects. We sketch out the objects of our faith, they say, in perceptible types and images, and by the immediate presence of these types make them more present to us than we possibly could by intellectual contemplation alone. Objects we can see and touch always have more influence on the fancy than anything else, and they readily pass that influence on to the ideas they are related to and resemble. All I shall infer from these practices and this reasoning is that the effect of resemblance in enlivening ideas is very common; and since in every case a resemblance and a present impression have to combine, we have experiments in abundance to prove the principle.
We can add force to these experiments with others of a different kind, by considering the effects of contiguity as well as of resemblance. Distance certainly weakens the force of every idea, and as we approach an object, even before it shows itself to our senses, it works on the mind with an influence that imitates an immediate impression. Thinking about any object readily carries the mind to whatever is next to it; but only the actual presence of an object carries it with superior liveliness. When I am a few miles from home, everything to do with home touches me more nearly than when I am two hundred leagues away — though even at that distance, thinking about anything near my friends or family naturally produces an idea of them. But in the second case both objects before the mind are ideas, and although the transition between them is easy, the transition alone cannot give either of them superior liveliness, for want of some immediate impression.
Nobody can doubt that causation works the same way as resemblance and contiguity. Superstitious people are fond of the relics of saints and holy men for the same reason that they look for images: to enliven their devotion and get a closer, stronger conception of the exemplary lives they want to imitate. Now plainly one of the best relics a devotee could get hold of would be something a saint had made with his own hands — and if his clothes and furniture are ever regarded in that light, it is because they were once his, and were handled and affected by him, so that they count as imperfect effects, connected to him by a shorter chain of consequences than anything else we learn his existence from.
Suppose the son of a friend long dead or long absent were brought before us. Plainly the sight would instantly revive the associated idea, and call back all our old intimacies in livelier colours than they would otherwise have appeared in. That is another phenomenon which seems to prove the principle.
Notice that in all these cases the belief in the associated object is always presupposed, and without it the relation could have no effect at all. The influence of the picture assumes that we believe our friend once existed. Being near home can never excite our ideas of home unless we believe home really exists. Now I maintain that this belief, where it reaches beyond memory and the senses, is of the same nature and arises from the same causes as the transition of thought and liveliness of conception just described. When I throw a dry piece of wood on a fire, my mind is immediately carried to the thought that it will feed the flame, not put it out. That transition of thought from cause to effect does not come from reason; it originates entirely in custom and experience. And because it starts from an object present to the senses, it makes the idea of flame stronger and livelier than any loose, floating daydream. The idea arises at once. The thought moves instantly towards it, carrying to it all the force of conception derived from the present impression. When a sword is levelled at my chest, does not the idea of a wound and of pain strike me more forcibly than when a glass of wine is held out to me — even supposing the same idea happened to occur to me after the wine? But what is there in the whole business to produce so strong a conception, except a present object and a customary transition to the idea of another object we are used to finding joined with it? That is the whole operation of the mind in all our conclusions about matters of fact and existence, and it is a satisfaction to find some analogies that help explain it. The transition from a present object always gives strength and solidity to the related idea.
So here is a sort of pre-established harmony between the course of nature and the succession of our ideas. Though the powers and forces governing nature are entirely unknown to us, our thoughts and conceptions have nevertheless, we find, run along in the same track as the rest of nature's work. Custom is the principle by which this correspondence has been brought about — so necessary to the survival of our species and to the regulation of our conduct in every situation life produces. If the presence of an object had not instantly aroused the idea of the objects commonly joined with it, all our knowledge would have been confined to the narrow sphere of memory and the senses, and we could never have fitted means to ends, or used our natural powers either to produce good or to avoid harm. Those who delight in discovering and contemplating final causes have ample material here for their wonder.
Let me add one more confirmation of this theory. Since the operation of mind by which we infer like effects from like causes, and the reverse, is so essential to the survival of every human creature, it is unlikely that it could have been entrusted to the unreliable deductions of our reason — which works slowly, does not appear at all in the first years of infancy, and at best is extremely liable to error at every age. It is more in keeping with nature's ordinary wisdom to secure so necessary an act of the mind by some instinct or mechanical tendency, which can be infallible in its working, can show itself at the first appearance of life and thought, and can be independent of all the laboured deductions of the understanding. Just as nature has taught us the use of our limbs without giving us any knowledge of the muscles and nerves that move them, so she has planted in us an instinct that carries our thought forward on a course matching the one she has established among external objects — even though we know nothing of the powers and forces on which that regular course and succession of objects entirely depends.
Though there is no such thing as Chance in the world, our ignorance of the real cause of an event has the same effect on the understanding and produces the same sort of belief.
There is certainly a kind of probability that comes from having more chances on one side than the other; and as that superiority grows and outstrips the opposing chances, the probability rises in proportion and produces a still higher degree of belief in the favoured side. If a die were marked with one number of spots on four faces and another number on the remaining two, the first would be more likely to come up than the second — and if it had a thousand faces marked alike and only one face different, the probability would be far higher and our expectation steadier and more secure. This process of thought may look trivial and obvious, but anyone who examines it more closely may find something worth curious speculation in it.
It seems clear that when the mind looks ahead to see what will come of throwing such a die, it treats the turning up of each particular face as equally likely — and that is exactly what chance is, the making of every particular outcome inside it entirely equal. But finding that more faces point to one result than to the other, the mind is carried more often to that result, and meets it more frequently as it runs over the various possibilities the final outcome depends on. This convergence of several views on one particular result immediately produces, by some inexplicable contrivance of nature, the feeling of belief, and gives that result the advantage over its rival, which fewer views support and which comes back to the mind less often. If we grant that belief is nothing but a firmer and stronger conception of an object than the one attending the mere fictions of imagination, this operation can perhaps be accounted for to some extent. The convergence of these several views stamps the idea more strongly on the imagination, gives it superior force, makes its influence on the passions more perceptible, and in a word produces the reliance or security that belief consists in.
Probability from causes works the same way as probability from chance. Some causes are entirely uniform and constant in producing a particular effect, and no instance of failure or irregularity in them has ever been found. Fire has always burned, and water always drowned every human creature; the production of motion by impact and by gravity is a universal law that has so far admitted no exception. But other causes have been found more irregular and uncertain: rhubarb has not always purged, nor opium put to sleep everyone who took it. It is true that when a cause fails to produce its usual effect, philosophers do not put this down to any irregularity in nature, but suppose that some hidden cause in the particular structure of the parts has prevented it from working. Our reasoning and our conclusions about the event, however, are the same as if no such principle existed. Since custom determines us to carry the past over to the future in all our inferences, where the past has been entirely regular we expect the event with the greatest confidence and leave no room for any contrary supposition. But where different effects have been found to follow causes that are to appearance exactly alike, all these various effects must occur to the mind as it carries the past over to the future, and must be taken into account when we settle how probable the event is. Though we prefer the effect that has been found most usual and believe it will happen, we must not overlook the others; each of them must be given its own weight and authority in proportion to how frequently we have found it. In almost every country in Europe it is more probable that there will be frost at some point in January than that the whole month will stay mild — though this probability varies with the climate and comes near certainty in the more northern kingdoms.
Here, then, it seems clear that when we carry the past over to the future in order to settle what effect a cause will have, we carry over all the different outcomes in the same proportions they appeared in before, conceiving one to have happened a hundred times, say, another ten times, and another once. And since a great many views converge here on one outcome, they fortify and confirm it to the imagination, produce the feeling we call belief, and give its object the preference over the contrary outcome, which fewer trials support and which does not come back to the mind so often as we carry the past over to the future. Let anyone try to account for this operation of the mind on any of the received systems of philosophy, and he will feel the difficulty. For my part I shall be satisfied if these hints arouse the curiosity of philosophers, and make them aware how inadequate all the usual theories are on subjects so curious and so lofty.
The great advantage the mathematical sciences have over the moral ones is that mathematical ideas, being perceptible, are always clear and definite; the smallest distinction between them is immediately noticeable, and the same terms go on expressing the same ideas without ambiguity or drift. An oval is never mistaken for a circle, nor a hyperbola for an ellipse. An isosceles triangle and a scalene one are marked off by more exact boundaries than vice and virtue, right and wrong. If a term is defined in geometry, the mind readily substitutes the definition for the term on every occasion; and even where no definition is used, the object itself can be presented to the senses and steadily grasped that way. But the finer feelings of the mind, the operations of the understanding, the various agitations of the passions — though genuinely distinct in themselves — easily slip away from us when we survey them by reflection, and it is not in our power to summon back the original object every time we need to look at it. Ambiguity gradually creeps into our reasoning this way. Objects that merely resemble each other get taken for the same, and the conclusion ends up a long way from the premises.
Still, one may safely say that if these sciences are viewed properly, their advantages and disadvantages roughly cancel out and leave them level. If the mind retains the ideas of geometry clear and definite more easily, it also has to carry on a much longer and more intricate chain of reasoning, and compare ideas much further apart, to reach that science's deeper truths. And if moral ideas are apt to slide into obscurity and confusion without extreme care, the inferences in such enquiries are always much shorter, and the intermediate steps far fewer, than in the sciences of quantity and number. In fact there is scarcely a proposition in Euclid so simple that it does not have more parts than any piece of moral reasoning that stays clear of fantasy. When we can trace the principles of the human mind through a few steps, we may be well satisfied with our progress, considering how soon nature bars all our enquiries into causes and reduces us to admitting our ignorance. The chief obstacle to progress in the moral or metaphysical sciences, then, is the obscurity of the ideas and the ambiguity of the terms. The chief difficulty in mathematics is the length of the inferences and the reach of thought needed to form any conclusion. And our progress in natural philosophy is probably held back mainly by the lack of the right experiments and phenomena, which are often found by accident and cannot always be produced when they are wanted, even by the most diligent enquiry. Since moral philosophy seems so far to have advanced less than either geometry or physics, we may conclude that if there is any difference among these sciences in this respect, the difficulties obstructing the first require greater care and greater ability to overcome.
No ideas in metaphysics are more obscure and uncertain than those of power, force, energy or necessary connection, which we are obliged to handle at every moment in every enquiry. So in this section I shall try, if possible, to fix the precise meaning of these terms, and thereby remove some part of the obscurity that people complain of so much in this kind of philosophy.
It seems a proposition not open to much dispute that all our ideas are nothing but copies of our impressions — in other words, that it is impossible for us to think of anything we have not previously felt, by the outer senses or the inner ones. I have tried to explain and prove this proposition, and have said I hope that by using it properly people may reach greater clarity and precision in philosophical reasoning than they have so far managed. Complex ideas can perhaps be well enough known by definition, which is nothing but a listing of the parts, the simple ideas, that make them up. But when we have pushed our definitions down to the simplest ideas and still find some ambiguity and obscurity, what resource is left to us? By what device can we throw light on these ideas and make them altogether precise? Produce the impressions, the original feelings, that the ideas were copied from. These impressions are all strong and vivid. They admit of no ambiguity. Not only are they in full light themselves; they can throw light on the corresponding ideas lying in the dark. And by this means we may perhaps arrive at a new microscope, a new kind of optics, by which in the moral sciences the smallest and simplest ideas can be enlarged enough to fall easily within our grasp, and be known as well as the coarsest and most obvious ideas we ever enquire into.
To get fully acquainted with the idea of power, or necessary connection, then, let us examine its impression — and to find that impression with more certainty, let us look for it in every source it could possibly have come from.
When we look around us at external objects and consider causes at work, we are never able in a single instance to make out any power or necessary connection: any quality that binds the effect to the cause and makes the one an infallible consequence of the other. All we find is that the one does, as a matter of fact, follow the other. The impact of one billiard ball is followed by motion in the second. That is the whole of what appears to the outward senses. The mind gets no feeling, no inward impression, from this succession of objects. Consequently there is nothing in any single instance of cause and effect that could suggest the idea of power or necessary connection.
From the first appearance of an object we can never guess what effect will follow from it. But if the power or energy of a cause could be made out by the mind, we could foresee the effect even without experience, and could pronounce on it with certainty at once by sheer thought and reasoning.
In fact there is no part of matter that ever reveals, through the qualities we can perceive, any power or energy, or gives us grounds to imagine that it could produce anything, or be followed by any other object we could call its effect. Solidity, extension, motion — these qualities are all complete in themselves and never point to any further event that might follow from them. The scenes of the universe are continually shifting, and one object follows another in an unbroken succession; but the power or force that drives the whole machine is entirely hidden from us, and never shows itself in any perceptible quality of a body. We know that heat is in fact a constant companion of flame; but what the connection between them is, we have not even room to guess. So the idea of power cannot possibly come from contemplating bodies in single instances of their operation, because no body ever reveals any power that could be the origin of the idea.
Since external objects as they appear to the senses give us no idea of power or necessary connection through what they do in particular instances, let us see whether the idea comes from reflecting on the operations of our own minds, and is copied from some inward impression. It may be said that we are conscious of an inward power at every moment, since we feel that by a simple command of the will we can move the organs of our body or direct the faculties of our mind. An act of will produces motion in our limbs, or raises a new idea in our imagination. We know this influence of the will by consciousness. From it we get the idea of power or energy, and we are certain that we ourselves, and all other intelligent beings, possess power. The idea, on this view, is an idea of reflection, since it arises from reflecting on the operations of our own mind, and on the command the will exercises over the organs of the body and the faculties of the soul.
Let us examine this claim, and first with regard to the will's influence over the organs of the body. This influence is a fact which, like every other natural event, can be known only by experience, and can never be foreseen from any apparent energy or power in the cause that would connect it with the effect and make the one an infallible consequence of the other. Our body moves at the command of our will; we are conscious of that every moment. But the means by which it is done, the energy by which the will performs so extraordinary an operation — of that we are so far from being immediately conscious that it must for ever escape our most diligent enquiry.
For first: is there any principle in all nature more mysterious than the union of soul with body, by which a supposedly spiritual substance acquires such influence over a material one that the most refined thought is able to move the grossest matter? If we were empowered to move mountains by a secret wish, or to steer the planets in their orbits, that far-reaching authority would be no more extraordinary and no further beyond our comprehension. But if we perceived any power or energy in the will by consciousness, we should have to know that power; we should have to know its connection with the effect; we should have to know the hidden union of soul and body, and the nature of both substances, by which the one is able to act on the other in so many cases.
Second: we cannot move all the organs of the body with the same authority, and we can give no reason for so remarkable a difference except experience. Why does the will have influence over the tongue and the fingers, but not over the heart or the liver? The question would never trouble us if we were conscious of a power in the first case and not in the second. We should then see, independently of experience, why the will's authority over the body's organs is confined within just those limits. Being in that case fully acquainted with the power by which it works, we should also know why its influence reaches exactly so far and no further.
A man suddenly struck with palsy in the leg or arm, or who has just lost those limbs, often tries at first to move them and use them as usual. He is as conscious of a power to command those limbs as a healthy man is of a power to move any limb still in its natural condition. But consciousness never deceives. Consequently in neither case are we ever conscious of any power at all. We learn the influence of our will from experience alone — and experience only teaches us that one event constantly follows another, without instructing us in the hidden connection that binds them together and makes them inseparable.
Third: we learn from anatomy that the immediate object of power in voluntary motion is not the limb that moves, but certain muscles and nerves and animal spirits — and perhaps something smaller and less known still — through which the motion is passed along step by step before it reaches the limb whose movement was what the will actually intended. Could there be a surer proof that the power performing this whole operation, so far from being directly and fully known by an inward feeling, is mysterious and unintelligible in the last degree? Here the mind wills a certain event; immediately another event, unknown to us and entirely different from the one intended, is produced; that event produces another, equally unknown; until at last, through a long succession, the desired event comes about. But if the original power were felt, it would have to be known; and if it were known, its effect would have to be known too, since all power is relative to its effect. And conversely, if the effect is not known, the power can be neither known nor felt. How indeed can we be conscious of a power to move our limbs, when we have no such power — only a power to move certain animal spirits, which do produce the motion of our limbs in the end, but work in a way entirely beyond our comprehension?
We may conclude from all this, I hope without rashness though with confidence, that our idea of power is not copied from any feeling or consciousness of power within ourselves when we set our bodies in motion or put our limbs to their proper use. That they move at the command of the will is a matter of common experience, like other natural events; but the power by which it is done, like the power in other natural events, is unknown and inconceivable.
Shall we say, then, that we are conscious of a power in our own minds when, by an act of will, we raise up a new idea, fix the mind on contemplating it, turn it over on all sides, and finally dismiss it for some other idea once we think we have examined it closely enough? I believe the same arguments will show that even this command of the will gives us no real idea of force.
First, it must be granted that when we know a power, we know the very feature in the cause that enables it to produce the effect — these are taken to be the same thing. So we should have to know both cause and effect, and the relation between them. But do we claim to be acquainted with the nature of the human soul, and the nature of an idea, and the fitness of the one to produce the other? This is a real creation, a production of something out of nothing, which implies a power so great that it might seem at first sight beyond the reach of any being short of an infinite one. At the very least it must be admitted that no such power is felt, or known, or even conceivable by the mind. All we feel is the event — the existence of an idea following a command of the will. The manner in which the operation is performed, and the power that produces it, are entirely beyond our comprehension.
Second, the mind's command over itself is limited, just as its command over the body is, and the limits are not known by reason or by any acquaintance with the nature of cause and effect, but only by experience and observation, as with every other natural event and with the working of external objects. Our authority over our feelings and passions is much weaker than over our ideas, and even that authority is confined within very narrow bounds. Will anyone claim to give the ultimate reason for these bounds, or to show why the power falls short in one case and not in another?
Third, this self-command varies greatly from one time to another. A man in health has more of it than one weakened by sickness. We are more master of our thoughts in the morning than in the evening, and fasting than after a heavy meal. Can we give any reason for these variations except experience? Where, then, is this power we claim to be conscious of? Is there not, either in a spiritual substance or a material one or both, some hidden mechanism or structure of parts on which the effect depends — and which, being entirely unknown to us, leaves the power of the will equally unknown and incomprehensible?
An act of will is surely something we know well enough. Reflect on it. Consider it from every side. Do you find anything in it like this creative power, by which it raises a new idea out of nothing, and with a kind of Fiat imitates the omnipotence of its Maker — if I may put it that way — who called all the various scenes of nature into existence? So far from being conscious of any such energy in the will, we need experience as sure as the experience we have to convince us that such extraordinary effects ever do follow from a simple act of will.
Most people never find any difficulty in accounting for nature's more common and familiar operations — heavy bodies falling, plants growing, animals being born, bodies nourished by food. They suppose that in all these cases they perceive the very force in the cause by which it is connected with its effect and is for ever infallible in what it does. Long habit gives them such a cast of mind that as soon as the cause appears they confidently expect its usual companion, and can hardly conceive that any other result was possible. It is only when they meet extraordinary phenomena — earthquakes, plagues, marvels of any kind — that they find themselves at a loss to assign a proper cause and explain how the effect was produced. In such difficulties people usually fall back on some invisible intelligent principle as the immediate cause of the event that has surprised them, and which they think the ordinary powers of nature cannot account for. But philosophers who carry their scrutiny a little further see at once that even in the most familiar events the energy of the cause is exactly as unintelligible as in the strangest, and that experience only ever teaches us the frequent Conjunction of objects, without our being able to grasp anything like a Connection between them.
At this point many philosophers think reason obliges them to fall back on every occasion upon the same principle that ordinary people appeal to only in cases that look miraculous. They hold that mind and intelligence is not merely the ultimate and original cause of everything but the immediate and only cause of every event in nature. The objects usually called causes, they claim, are really nothing but occasions; the true and direct principle behind every effect is not any power in nature but an act of will in the Supreme Being, who wills that these particular objects should be joined together for ever. Instead of saying that one billiard ball moves another by a force it derived from the author of nature, they say it is God himself who moves the second ball by a particular act of will, being determined to do so by the impact of the first, in accordance with the general laws he has laid down for himself in governing the universe. But as philosophers press their enquiries further, they discover that since we are entirely ignorant of the power behind the mutual action of bodies, we are just as ignorant of the power behind the action of mind on body, or of body on mind; neither our senses nor our consciousness can name the ultimate principle in the one case any more than in the other. So the same ignorance drives them to the same conclusion. They assert that God is the immediate cause of the union between soul and body: that it is not the sense organs, agitated by external objects, that produce sensations in the mind, but a particular act of will in our omnipotent Maker, which excites the sensation as a consequence of the motion in the organ. In the same way it is not any energy in the will that moves our limbs; it is God himself, who is pleased to back up our will — powerless in itself — and to command the motion we mistakenly credit to our own power. Nor do philosophers stop there. They sometimes extend the same inference to the mind's own inner operations. Our mental view of ideas is nothing but a revelation made to us by our Maker. When we deliberately turn our thoughts to some object and raise its image in the fancy, it is not the will that creates the idea; it is the universal Creator, who reveals it to the mind and makes it present to us.
So on this view everything is full of God. Not content with the principle that nothing exists except by his will and nothing has any power except by his permission, they strip nature and every created being of all power, in order to make their dependence on God still more immediate. They do not notice that this theory diminishes rather than magnifies the grandeur of the attributes they are so keen to celebrate. It surely argues more power in God to delegate a certain degree of power to lesser creatures than to produce everything by his own immediate will. It argues more wisdom to design the fabric of the world at the outset with such perfect foresight that it will serve all the purposes of providence by its own operation, than if the great Creator had to adjust its parts every moment and animate every wheel of that stupendous machine with his own breath.
But if we want a more philosophical refutation of this theory, perhaps the following two reflections will do.
First, it seems to me that this theory of the universal action of the Supreme Being is too bold ever to carry conviction with a man who is sufficiently aware of the weakness of human reason and the narrow limits it works within. However logical the chain of arguments leading to it, there must arise a strong suspicion — if not an absolute certainty — that it has carried us clean beyond the reach of our faculties, when it leads to conclusions so extraordinary and so remote from ordinary life and experience. We have got into fairyland long before we reach the last steps of the theory, and there we have no reason to trust our usual methods of argument, or to think our usual analogies and probabilities carry any authority. Our line is too short to sound such immense depths. And however we may flatter ourselves that every step we take is guided by a kind of likelihood and experience, we may be sure this imagined experience has no authority when we apply it to subjects lying entirely outside the sphere of experience. But we shall have occasion to touch on this later.
Second, I cannot see any force in the arguments this theory is founded on. We are ignorant, true, of the way bodies act on one another; their force is entirely incomprehensible. But are we not equally ignorant of the manner or force by which a mind — even the supreme mind — acts either on itself or on a body? Where, I ask you, do we get any idea of it? We have no feeling or consciousness of such a power in ourselves. We have no idea of the Supreme Being except what we learn from reflecting on our own faculties. So if our ignorance were a good reason for rejecting anything, it would lead us to deny all energy in the Supreme Being just as much as in the grossest matter. We understand the operations of the one quite as little as the other. Is it any harder to conceive that motion may arise from impact than that it may arise from an act of will? All we know, in both cases, is our own profound ignorance.
But to hurry towards a conclusion of this argument, which has already run on too long: we have looked in vain for an idea of power or necessary connection in every source it could be supposed to come from. It appears that in single instances of bodies acting, the closest scrutiny can never show us anything but one event following another, without our being able to grasp any force by which the cause operates, or any connection between it and its supposed effect. The same difficulty arises when we consider mind acting on body — where we observe the body's motion following the mind's act of will, but cannot observe or conceive the tie binding motion and will together, or the energy by which the mind produces the effect. The will's authority over its own faculties and ideas is not a whit more comprehensible. So on the whole there does not appear, anywhere in nature, a single instance of connection that we can conceive. All events seem entirely loose and separate. One event follows another, but we can never observe any tie between them. They seem conjoined but never connected. And since we can have no idea of anything that never appeared to our outward senses or inward feeling, the necessary conclusion seems to be that we have no idea of connection or power at all, and that these words are completely without meaning, whether used in philosophical reasoning or in ordinary life.
But there is still one way of avoiding this conclusion, and one source we have not yet examined. When any natural object or event is put in front of us, no amount of shrewdness can discover, or even guess, without experience, what event will follow from it, or carry our foresight beyond the object immediately present to memory and the senses. Even after a single instance in which we have seen one particular event follow another, we are not entitled to form a general rule or predict what will happen in similar cases — it is rightly reckoned unpardonable rashness to judge the whole course of nature from one experiment, however careful. But when one particular kind of event has always, in every instance, been joined with another, we no longer hesitate to predict the one on the appearance of the other, and to use the reasoning that alone can assure us of any matter of fact. We then call the one object the Cause and the other the Effect. We suppose there is some connection between them, some power in the one by which it infallibly produces the other, acting with the greatest certainty and the strongest necessity.
It appears, then, that this idea of a necessary connection among events arises from a number of similar instances of the constant conjunction of those events, and that the idea can never be suggested by any one of those instances, surveyed in every possible light and position. But there is nothing in a number of instances that is not in every single instance, supposed exactly similar — nothing except this: that after a repetition of similar instances, habit carries the mind, on the appearance of one event, to expect its usual companion and to believe it will occur. So this connection that we feel in the mind, this customary transition of the imagination from one object to its usual companion, is the feeling or impression from which we form the idea of power or necessary connection. There is nothing else in the case. Consider the subject from every side and you will never find any other origin for the idea. That is the sole difference between one instance, from which we can never get the idea of connection, and a number of similar instances, which suggest it. The first time a man saw motion passed on by impact, as in the collision of two billiard balls, he could not say that the one event was connected with the other, only that it was conjoined with it. After observing several instances of the kind, he pronounces them connected. What change has occurred to give rise to this new idea of connection? Nothing but this: he now feels the events to be connected in his imagination, and can readily predict the one from the appearance of the other. So when we say that one object is connected with another, all we mean is that they have acquired a connection in our thought, and give rise to the inference by which each becomes proof of the other's existence. This is a somewhat extraordinary conclusion, but it seems to rest on sufficient evidence. Nor is its evidence weakened by any general distrust of the understanding, or sceptical suspicion of every conclusion that is new and strange. No conclusions could suit scepticism better than ones that make discoveries about the weakness and narrow limits of human reason.
And what stronger instance of the surprising ignorance and weakness of the understanding could be produced than this one? For surely if there is any relation among objects that it matters to us to know perfectly, it is cause and effect. All our reasoning about matter of fact rests on it. By it alone do we get any assurance about objects removed from the present testimony of memory and the senses. The one immediate use of all the sciences is to teach us how to control future events through their causes. Our thoughts and enquiries are therefore engaged with this relation at every moment — and yet the ideas we form of it are so imperfect that it is impossible to give any proper definition of a cause except one drawn from something outside it altogether.
Similar objects are always joined with similar. Of this we have experience. In keeping with that experience, then, we may define a cause to be an object followed by another, and where all the objects similar to the first are followed by objects similar to the second. Or in other words, where, if the first object had not been, the second never would have existed. The appearance of a cause always carries the mind, by a customary transition, to the idea of the effect. Of this too we have experience. So in keeping with that experience we may form another definition of a cause, and call it an object followed by another, and whose appearance always carries the thought to that other. But though both definitions are drawn from circumstances outside the cause, we cannot remedy the inconvenience or arrive at any better definition, one that would point out the feature in the cause that gives it a connection with its effect. We have no idea of that connection — not even any distinct notion of what it is we want to know when we try to conceive it. We say, for instance, that the vibration of this string is the cause of this particular sound. But what do we mean by that? We mean either that this vibration is followed by this sound, and that all similar vibrations have been followed by similar sounds, or else that this vibration is followed by this sound, and that on the appearance of the one the mind runs ahead of the senses and immediately forms an idea of the other. We may take cause and effect in either of these two ways; beyond them we have no idea of it.
To sum up the reasoning of this section, then. Every idea is copied from some preceding impression or feeling, and where we can find no impression we may be certain there is no idea. In all single instances of bodies or minds at work there is nothing that produces any impression, and so nothing that can suggest any idea of power or necessary connection. But when many uniform instances appear, and the same object is always followed by the same event, we begin to entertain the notion of cause and connection. We then feel a new impression — a customary connection in thought between one object and its usual companion — and that feeling is the original of the idea we were looking for. Since the idea arises from a number of similar instances and not from any single one, it must arise from whatever it is that makes a number of instances differ from an individual instance. But this customary connection or transition of the imagination is the only respect in which they do differ; in every other particular they are alike. The first instance we ever saw of motion passed on by the collision of two billiard balls — to come back to that obvious illustration — is exactly like any instance that may occur to us now, except in this one respect: that at first we could not infer the one event from the other, and now, after so long a run of uniform experience, we can.
I do not know whether the reader will take this reasoning in easily. I am afraid that multiplying words about it, or throwing it into a greater variety of lights, would only make it more obscure. In all abstract reasoning there is one point of view which, if we are lucky enough to hit on it, does more to illuminate the subject than all the eloquence in the world. That is the point of view we should try to reach, saving the flowers of rhetoric for subjects better suited to them.
You might reasonably expect that in questions argued over with great eagerness ever since science and philosophy began, the disputants would at least have agreed on what the terms mean, and that in the course of two thousand years our enquiries would have got past the words to the real subject of the controversy. How easy it seems to give exact definitions of the terms used in an argument, and to make those definitions, rather than the mere sound of words, the thing examined afterwards. But look at the matter more closely and we shall be inclined to draw exactly the opposite conclusion. From the single fact that a controversy has been kept going a long time and is still undecided, we may guess that there is some ambiguity in the language, and that the disputants attach different ideas to the terms. Since the faculties of the mind are supposed to be naturally alike in everybody — otherwise nothing could be more pointless than reasoning or arguing together — it would be impossible, if people attached the same ideas to their terms, for them to go on holding different opinions about the same subject for so long, especially when they communicate their views and each side turns itself in every direction looking for arguments to defeat the other. It is true that if people take up questions lying entirely beyond human capacity — the origin of worlds, say, or the arrangement of the realm of spirits — they may beat the air in fruitless contests for a very long time and never arrive at any settled conclusion. But if the question concerns some subject of ordinary life and experience, one would think nothing could keep the dispute undecided so long except some ambiguous expressions, which hold the antagonists apart and stop them ever getting to grips with each other.
This has been the case in the long-disputed question of liberty and necessity — and to such a remarkable degree that, unless I am much mistaken, we shall find that all mankind, learned and ignorant alike, have always held the same opinion on the subject, and that a few intelligible definitions would have ended the whole controversy at once. I admit the dispute has been so thoroughly worked over on all sides, and has led philosophers into such a labyrinth of obscure sophistry, that it would be no wonder if a sensible reader spared himself the trouble and turned a deaf ear to a question he can expect neither instruction nor entertainment from. But the way the argument is set out here may perhaps renew his attention: it has more novelty, it promises at least some settling of the controversy, and it will not trouble him with any intricate or obscure reasoning.
So I hope to show that everyone has always agreed on the doctrine both of necessity and of liberty, on any reasonable sense that can be given to those terms, and that the whole controversy has so far turned merely on words. We shall begin by examining the doctrine of necessity.
It is universally granted that matter in everything it does is driven by a necessary force, and that every natural effect is so precisely determined by the energy of its cause that no other effect could possibly have followed in those particular circumstances. The degree and direction of every motion is prescribed by the laws of nature so exactly that a living creature could as easily arise from the collision of two bodies as a motion of any degree or direction other than the one actually produced. So if we want a just and precise idea of necessity, we must consider where the idea comes from when we apply it to what bodies do.
It seems clear that if all the scenes of nature were continually shifting in such a way that no two events resembled each other, and every object were entirely new with no likeness to anything ever seen before, we should never in that case have arrived at the least idea of necessity, or of a connection among these objects. On that supposition we might say that one object or event had followed another, but not that one was produced by the other. Cause and effect would be entirely unknown to mankind. Inference and reasoning about the operations of nature would end from that moment, and memory and the senses would remain the only channels by which knowledge of any real existence could reach the mind. Our idea of necessity and causation, then, arises entirely from the uniformity we can observe in nature's operations, where similar objects are constantly joined together and the mind is determined by custom to infer the one from the appearance of the other. These two circumstances are the whole of the necessity we attribute to matter. Beyond the constant conjunction of similar objects, and the inference we consequently make from one to the other, we have no notion of any necessity or connection at all.
So if it turns out that everyone has always granted, without doubt or hesitation, that these two circumstances occur in the voluntary actions of men and in the operations of the mind, it must follow that everyone has always agreed on the doctrine of necessity, and that they have been disputing merely for want of understanding each other.
As to the first circumstance, the constant and regular conjunction of similar events, the following considerations may satisfy us. It is universally acknowledged that there is a great uniformity in what people do, in all nations and ages, and that human nature stays the same in its principles and operations. The same motives always produce the same actions; the same events follow from the same causes. Ambition, greed, self-love, vanity, friendship, generosity, public spirit — these passions, mixed in various proportions and spread through society, have been from the beginning of the world, and still are, the source of every action and enterprise ever observed among mankind. Would you like to know the feelings, inclinations and way of life of the Greeks and Romans? Study the temper and behaviour of the French and English closely: you cannot go far wrong in transferring to the first most of the observations you have made about the second. Mankind is so much the same at all times and in all places that history tells us nothing new or strange in this respect. Its chief use is simply to reveal the constant and universal principles of human nature, by showing men in every variety of circumstance and supplying us with material from which to form our observations and get to know the regular springs of human behaviour. These records of wars, intrigues, factions and revolutions are so many collections of experiments, by which the politician or moral philosopher fixes the principles of his science, in just the way the physician or natural philosopher gets to know the nature of plants and minerals by the experiments he makes on them. The earth and water and other elements Aristotle and Hippocrates examined are no more like the ones we observe today than the men Polybius and Tacitus describe are like the men who govern the world now.
If a traveller returning from a distant country brought us an account of men entirely different from any we had ever known — men wholly free of greed, ambition or vengefulness, who knew no pleasure but friendship, generosity and public spirit — we should detect the falsehood immediately from those very details, and convict him of lying with the same certainty as if he had stuffed his story with centaurs and dragons. And if we want to demolish a forgery in history, we can use no more convincing argument than to prove that the actions attributed to some person run directly contrary to the course of nature, and that no human motive in those circumstances could ever have led him to behave so. Quintus Curtius is as much to be doubted when he describes the supernatural courage of Alexander, which drove him to attack multitudes single-handed, as when he describes the supernatural strength that let him withstand them. So readily and so universally do we acknowledge a uniformity in human motives and actions, as much as in the operations of bodies.
Hence too the value of the experience gained by a long life and a wide variety of business and company, which teaches us the principles of human nature and regulates our conduct as well as our speculation. Guided by it, we work up from people's actions, expressions and even gestures to a knowledge of their inclinations and motives, and then back down again to the interpretation of their actions from what we know of their motives. The general observations stored up over a course of experience give us the key to human nature and teach us to unravel all its intricacies. Pretexts and appearances no longer deceive us. Public declarations pass for the plausible colouring of a cause. And though virtue and honour are allowed their proper weight, that perfect disinterestedness which is so often claimed is never expected of crowds and parties, seldom of their leaders, and scarcely even of individuals of any rank. But if there were no uniformity in human actions, and every experiment we could make of this kind came out irregular and anomalous, it would be impossible to gather any general observations about mankind, and no experience, however carefully digested by reflection, would ever serve any purpose. Why is the old farmer more skilful at his work than the young beginner, except that there is a certain uniformity in the way sun and rain and earth work together to produce crops, and experience has taught the old hand the rules that govern it?
We must not, however, expect this uniformity of human action to be carried so far that everyone in the same circumstances will always behave in exactly the same way, with no allowance made for differences of character, prejudice and opinion. Such uniformity in every particular is found nowhere in nature. On the contrary, observing the variety of conduct in different people is what enables us to form a greater variety of maxims — maxims which still assume a degree of uniformity and regularity.
Are the manners of men different in different ages and countries? From that we learn the great force of custom and education, which mould the human mind from infancy and form it into a settled character. Is the behaviour of the one sex very unlike that of the other? It is from this that we come to know the different characters nature has stamped on the sexes and preserves with constancy and regularity. Are the actions of the same person very different at different periods of his life, from infancy to old age? That gives room for many general observations about the gradual change in our feelings and inclinations, and the different maxims that prevail at different ages. Even the characteristics peculiar to each individual have a uniformity in their influence — otherwise our acquaintance with people and our observation of their conduct could never teach us their dispositions, or help us direct our own behaviour towards them.
I grant it is possible to find some actions that seem to have no regular connection with any known motive, and that are exceptions to every rule of conduct ever laid down. But if we want to know what judgement to form about such irregular and extraordinary actions, we may consider what people commonly think about the irregular events that turn up in the course of nature. Not all causes are joined to their usual effects with the same uniformity. A craftsman handling nothing but dead matter can be disappointed of his aim, just as much as the politician directing the conduct of intelligent agents.
Ordinary people, who take things as they first appear, put the uncertainty of events down to an uncertainty in the causes, which they suppose often fail of their usual influence even though nothing obstructs them. But philosophers, noticing that almost every part of nature contains a vast variety of hidden springs and principles — hidden because they are too small or too far off to see — find that the contrariety of events may at least possibly come not from any contingency in the cause but from the secret working of contrary causes. Further observation turns this possibility into a certainty, when they notice that on exact examination a contrariety of effects always betrays a contrariety of causes, and comes from their opposing one another. A peasant can give no better reason for a clock stopping than to say it does not usually keep good time; but a craftsman easily sees that the same force in the spring or pendulum always has the same influence on the wheels, and fails of its usual effect only because of, say, a grain of dust that has brought the whole movement to a halt. From observing several parallel instances, philosophers form the maxim that the connection between all causes and effects is equally necessary, and that its apparent uncertainty in some cases comes from the secret opposition of contrary causes.
So, for instance, in the human body, when the usual symptoms of health or sickness disappoint our expectation, when medicines do not work with their accustomed power, when irregular events follow from some particular cause — the philosopher and the physician are not surprised, and are never tempted to deny in general the necessity and uniformity of the principles governing the animal economy. They know that a human body is an immensely complicated machine; that many hidden powers lurk in it entirely beyond our comprehension; that it must often look very uncertain in its operations to us; and that therefore the irregular events that show themselves outwardly are no proof that the laws of nature are not being observed with the greatest regularity in its inner workings.
The philosopher, if he is consistent, must apply the same reasoning to the actions and choices of intelligent agents. The most irregular and unexpected decisions people make can often be accounted for by anyone who knows every detail of their character and situation. An obliging man gives a peevish answer — but he has toothache, or has not had his dinner. A dull fellow shows unusual liveliness in his bearing — but he has had a sudden piece of good luck. And even when an action cannot be specifically accounted for, either by the person himself or by anyone else, we know in general that human characters are to some degree inconstant and irregular. That is, in a way, the constant character of human nature, though it applies more particularly to certain people who have no fixed rule for their conduct and go on in a continuous course of caprice. The inner principles and motives may still be working uniformly despite these apparent irregularities, in the same way that winds, rain, clouds and the other variations of weather are supposed to be governed by steady principles, even though human ingenuity cannot easily find them out.
So it appears not only that the conjunction between motives and voluntary actions is as regular and uniform as that between cause and effect anywhere in nature, but also that this regular conjunction has been universally acknowledged and has never been disputed, in philosophy or in ordinary life. Now since it is from past experience that we draw all our inferences about the future, and since we conclude that objects we have always found joined together will always be joined, it may seem superfluous to prove that this experienced uniformity in human actions is a source from which we draw inferences about them. But to throw the argument into a greater variety of lights, we shall dwell on this second point briefly as well.
People in every society depend on one another so much that hardly any human action is entirely complete in itself, or is performed without some reference to the actions of others, which are needed to make it fully answer the agent's intention. The poorest craftsman working alone expects at least the protection of the magistrate to secure him the fruits of his labour. He also expects that when he takes his goods to market and offers them at a reasonable price he will find buyers, and will be able with the money to get others to supply him with what he needs to live on. As people widen their dealings and make their relations with others more complicated, their plans for life always take in a greater variety of voluntary actions by other people, which they expect — from the appropriate motives — to cooperate with their own. In all these conclusions they take their measure from past experience, exactly as in their reasoning about external objects, and firmly believe that men, like the elements, will go on behaving as they have always been found to behave. A manufacturer counts on his workers' labour to get a job done just as he counts on his tools, and would be equally surprised if his expectations were disappointed. In short, this inference from experience about the actions of others runs so deep in human life that no waking man is ever without it for a moment. Have we not reason, then, to say that everyone has always agreed on the doctrine of necessity as it has just been defined?
Nor have philosophers ever held a different opinion from everyone else on this point. Quite apart from the fact that almost every action of their lives assumes it, there are few of even the speculative branches of learning where it is not essential. What would become of history, if we could not depend on the historian's truthfulness according to the experience we have had of mankind? How could politics be a science, if laws and forms of government had no uniform influence on society? Where would the foundation of morals be, if particular characters had no definite power to produce particular feelings, and if those feelings had no constant effect on actions? And with what excuse could we bring our criticism to bear on any poet, if we could not pronounce the conduct and feelings of his characters natural or unnatural for such people in such circumstances? It seems almost impossible, then, to engage in science or action of any kind without acknowledging the doctrine of necessity, and this inference from motive to voluntary action, from character to conduct.
And indeed, when we consider how neatly natural and moral evidence link together into a single chain of argument, we shall have no hesitation in allowing that they are of the same nature and come from the same principles. A prisoner with neither money nor influence sees the impossibility of escape as clearly when he considers the obstinacy of his gaoler as when he considers the walls and bars around him; and in all his attempts at freedom he chooses to work on the stone and iron rather than on the inflexible nature of the man. The same prisoner, led to the scaffold, foresees his death as certainly from the steadiness and loyalty of his guards as from the working of the axe. His mind runs along a certain train of ideas: the soldiers' refusal to let him escape; the executioner's action; the separation of head from body; bleeding, convulsions, death. Here is a connected chain of natural causes and voluntary actions — and the mind feels no difference between them as it passes from one link to the next, nor is it any less certain of the future event than if it were joined to the objects present to memory and the senses by a train of causes cemented together by what we like to call physical necessity. The same experienced union has the same effect on the mind, whether the objects united are motives, will and actions, or shape and motion. We may change the names of things, but their nature, and the way they work on the understanding, never change.
If a man I know to be honest and well off, and live in close friendship with, were to come into my house where I am surrounded by my servants, I rest assured that he is not going to stab me before he leaves in order to steal my silver inkstand — and I suspect that event no more than I suspect the house itself, which is new and solidly built, of falling in. But he might be seized by a sudden and unaccountable madness. So might a sudden earthquake come and shake the house down about my ears. So I shall change the case. I shall say that I know with certainty he is not going to put his hand into the fire and hold it there until it burns away; and I think I can predict that event with the same assurance as I can predict that if he throws himself out of the window and meets no obstruction he will not remain suspended in the air. No suspicion of an unaccountable madness can give the least possibility to the first event, which runs so contrary to every known principle of human nature. A man who leaves his purse full of gold on the pavement at Charing Cross at midday may as well expect it to fly away like a feather as expect to find it untouched an hour later. More than half of all human reasoning consists of inferences of this kind, carrying greater or less degrees of certainty in proportion to our experience of how people usually behave in such situations.
I have often wondered what the reason could be that all mankind, though they have always without hesitation acknowledged the doctrine of necessity in the whole of their practice and reasoning, have nevertheless shown such reluctance to acknowledge it in words, and have in every age rather tended to profess the opposite. I think the matter can be accounted for as follows. If we examine what bodies do, and how effects are produced from their causes, we find that all our faculties can never carry us further in our knowledge of that relation than merely to observe that particular objects are constantly conjoined, and that the mind is carried by a customary transition from the appearance of one to the belief in the other. But although this conclusion about human ignorance is the result of the strictest examination of the subject, people still have a strong tendency to believe that they see further into the powers of nature, and perceive something like a necessary connection between cause and effect. Then, when they turn their reflections on the operations of their own minds and feel no such connection between motive and action, they are inclined to suppose there is a difference between effects produced by material force and effects arising from thought. But once we are convinced that we know nothing of causation of any kind beyond the constant conjunction of objects and the inference the mind consequently makes from one to the other — and once we find that these two circumstances are universally granted to occur in voluntary actions — we may be led more easily to admit the same necessity in all causes alike. And though this reasoning contradicts the systems of many philosophers by ascribing necessity to the will's decisions, we shall find on reflection that they disagree with it in words only, not in what they really think. Necessity, in the sense taken here, has never yet been rejected and, I think, never can be rejected by any philosopher. It might perhaps be claimed that the mind can perceive some further connection between cause and effect in the operations of matter, a connection absent from the voluntary actions of intelligent beings. Whether that is so can only appear on examination, and it is up to those philosophers to make good the claim, by defining or describing that necessity and pointing it out to us in the working of material causes.
It seems, indeed, that people begin this question of liberty and necessity at the wrong end when they open it by examining the faculties of the soul, the influence of the understanding and the operations of the will. Let them first take up a simpler question — the operations of body, of brute unintelligent matter — and see whether they can form any idea of causation and necessity there beyond a constant conjunction of objects and the mind's subsequent inference from one to the other. If these circumstances really are the whole of the necessity we conceive in matter, and if they are also universally acknowledged to occur in the operations of the mind, the dispute is over, or at least must be admitted to be merely verbal from that point on. But as long as we rashly suppose that we have some further idea of necessity in the workings of external objects, while at the same time finding nothing further in the voluntary actions of the mind, there is no possibility of bringing the question to any settled conclusion while we go on from so mistaken an assumption. The only way to undeceive ourselves is to climb higher: to examine how narrow the scope of science is when applied to material causes, and to convince ourselves that all we know of them is the constant conjunction and the inference already described. We may find it hard to be brought to set such narrow limits to human understanding — but we shall find no difficulty afterwards in applying the doctrine to the actions of the will. For since these plainly have a regular conjunction with motives and circumstances and characters, and since we always draw inferences from one to the other, we shall be obliged to acknowledge in words the necessity we have already acknowledged in every deliberation of our lives and every step of our conduct.
But to go on with this reconciling project on the question of liberty and necessity — the most contentious question in metaphysics, the most contentious science — it will not take many words to prove that all mankind have always agreed on the doctrine of liberty as well as on that of necessity, and that here too the whole dispute has been merely verbal. What is meant by liberty, when it is applied to voluntary actions? We surely cannot mean that actions have so little connection with motives, inclinations and circumstances that the one does not follow from the other with a certain uniformity, and that the one gives us no inference by which to conclude the other exists. For those are plain and acknowledged matters of fact. By liberty, then, we can only mean a power of acting or not acting, according to the determinations of the will — that is, if we choose to stay still, we may, and if we choose to move, we may. Now this conditional liberty is universally allowed to belong to everyone who is not a prisoner in chains. So here there is nothing to dispute.
Whatever definition we give of liberty, we should be careful to observe two requirements: first, that it be consistent with plain matter of fact, and second, that it be consistent with itself. If we observe these, and make our definition intelligible, I am persuaded that all mankind will be found to be of one opinion about it.
It is universally allowed that nothing exists without a cause of its existence, and that chance, strictly examined, is a merely negative word and does not mean any real power existing anywhere in nature. But it is claimed that some causes are necessary and some are not. Here, then, is the advantage of definitions. Let anyone define a cause without including a necessary connection with its effect as part of the definition, and let him show clearly where the idea expressed by that definition comes from — and I shall readily give up the whole controversy. But if the account given above is accepted, this must be quite impossible. If objects did not have a regular conjunction with one another, we should never have formed any notion of cause and effect; and it is this regular conjunction that produces the inference of the understanding, which is the only connection we can have any grasp of at all. Anyone attempting a definition of cause that leaves out these circumstances will be obliged to use either unintelligible terms or terms synonymous with the one he is trying to define. And if the definition above is admitted, then liberty — when it is opposed to necessity rather than to constraint — is the same thing as chance, which everybody allows does not exist.
There is no method of reasoning more common in philosophical disputes, and none more blameworthy, than trying to refute a hypothesis by claiming it has dangerous consequences for religion and morality. When an opinion leads to absurdities it is certainly false; but an opinion is not certainly false because it is dangerous. Such lines of attack ought to be given up altogether: they do nothing to discover truth and serve only to make an opponent odious. I say this generally, without claiming any advantage from it. I frankly submit to an examination of that kind, and shall venture to say that the doctrines both of necessity and of liberty, as explained above, are not merely consistent with morality but absolutely essential to it.
Necessity can be defined two ways, matching the two definitions of cause it forms an essential part of. It consists either in the constant conjunction of like objects, or in the understanding's inference from one object to another. Now necessity in both these senses — which are at bottom the same — has universally, if tacitly, been allowed in the schools, in the pulpit and in ordinary life to belong to the human will; nobody has ever claimed to deny that we can draw inferences about human actions, or that those inferences rest on the experienced union of like actions with like motives, inclinations and circumstances. The only points on which anyone can differ are these. He may refuse to give the name of necessity to this property of human actions — but as long as the meaning is understood, I hope the word can do no harm. Or he may maintain that something further can be discovered in the operations of matter. But that, it must be admitted, can be of no consequence to morality or religion, whatever it may be to natural philosophy. We may be mistaken in asserting that there is no idea of any other necessity in the actions of bodies; but we certainly attribute nothing to the actions of the mind that everyone does not readily allow. We change nothing in the received orthodox system regarding the will — only what it says about material objects and causes. So nothing could be more harmless, at the very least, than this doctrine.
Since all law is founded on rewards and punishments, it is assumed as a fundamental principle that these motives have a regular and uniform influence on the mind, producing good actions and preventing bad ones. We may give that influence whatever name we like; but since it is regularly joined with the action, it must count as a cause, and be regarded as an instance of the very necessity we are establishing here.
The only proper object of hatred or vengeance is a person or creature endowed with thought and consciousness; and when criminal actions arouse that passion, it is only through their relation to the person. Actions by their very nature are temporary and perishing, and where they do not proceed from some cause in the character of the person who performed them, they can bring him neither honour if they were good nor infamy if they were bad. The actions themselves may be blameworthy; they may be contrary to every rule of morality and religion. But the person is not answerable for them; and since they came from nothing in him that is durable and leave nothing of that kind behind them, he cannot possibly become the object of punishment on their account. On the principle that denies necessity, and consequently denies causes, a man is as pure and untainted after committing the most horrid crime as at the first moment of his birth, and his character is in no way involved in his actions, since they did not come from it, and the wickedness of the one can never be used to prove the depravity of the other.
People are not blamed for actions they perform in ignorance or by accident, whatever the consequences. Why not? Because the principles behind such actions are only momentary and end with them. People are blamed less for actions done hastily and without premeditation than for actions that come from deliberation. Why? Because a hasty temper, though a constant principle in the mind, works only intermittently and does not infect the whole character. Again, repentance wipes out every crime if it is accompanied by a reformation of life. How is that to be accounted for? Only by saying that actions make a person criminal merely as evidence of criminal principles in his mind — and when a change in those principles means the actions are no longer good evidence of them, they stop being criminal too. But except on the doctrine of necessity, they never were good evidence, and so never were criminal at all.
It is just as easy to prove, by the same arguments, that liberty — in the sense defined above, which everyone agrees on — is also essential to morality, and that where it is missing, no human action is capable of any moral quality or can be an object of approval or dislike. For since actions are objects of our moral feeling only so far as they indicate the inner character and passions, they cannot possibly give rise to praise or blame where they do not come from those principles but result entirely from external force.
I do not claim to have anticipated and removed every objection to this account of necessity and liberty. I can foresee others, drawn from matters not dealt with here. It may be said, for instance, that if voluntary actions are subject to the same laws of necessity as the operations of matter, there is a continuous chain of necessary causes, preordained and predetermined, running from the original cause of everything down to every single act of will of every human creature. No contingency anywhere in the universe; no indifference; no liberty. While we act, we are at the same time acted upon. The ultimate Author of all our acts of will is the Creator of the world, who first gave motion to this immense machine and placed all beings in the particular position from which every subsequent event must follow by an inevitable necessity. So human actions can either have no moral wickedness at all, since they come from so good a cause; or if they are wicked, they must implicate our Creator in the same guilt, since he is acknowledged to be their ultimate author. For just as a man who fires a mine is answerable for all the consequences, whether the fuse he used was long or short, so wherever a continuous chain of necessary causes is fixed, the Being — finite or infinite — who produces the first is likewise the author of all the rest, and must bear the blame and take the praise belonging to them. Our clear and unalterable ideas of morality establish this rule on unquestionable grounds when we examine the consequences of any human action; and these grounds must have still greater force applied to the intentions of a Being infinitely wise and powerful. Ignorance or powerlessness may be pleaded for a creature as limited as man; but those imperfections have no place in our Creator. He foresaw, he ordained, he intended all those human actions we so rashly pronounce criminal. So we must conclude either that they are not criminal, or that God and not man is accountable for them. But since either position is absurd and impious, it follows that the doctrine they are deduced from cannot possibly be true, being open to all the same objections. An absurd consequence, if it is necessary, proves the original doctrine absurd — in the same way that criminal actions make their original cause criminal, if the connection between them is necessary and inescapable.
This objection has two parts, which we shall examine separately. First, that if human actions can be traced by a necessary chain back to God, they can never be criminal, on account of the infinite perfection of the Being they come from, who can intend nothing but what is altogether good. Or second, that if they are criminal, we must withdraw the attribute of perfection we ascribe to God, and acknowledge him to be the ultimate author of guilt and moral wickedness in all his creatures.
The answer to the first objection seems obvious and convincing. There are many philosophers who, after an exact examination of all the phenomena of nature, conclude that the whole, considered as one system, is ordered at every period of its existence with perfect benevolence, and that the greatest possible happiness will in the end result to all created beings, with no admixture of positive or absolute evil. Every physical evil, they say, is an essential part of this benevolent system and could not possibly be removed, even by God himself considered as a wise agent, without letting in a greater evil or shutting out a greater good that will come of it. From this theory some philosophers, the ancient Stoics among them, drew a source of consolation under every affliction, teaching their pupils that the ills they suffered were really goods to the universe, and that to a wider view taking in the whole system of nature, every event became a cause for joy. But though this line is plausible and lofty, it was soon found weak and useless in practice. You would surely irritate rather than soothe a man in the racking pains of gout by preaching to him about the rightness of the general laws that produced the malignant humours in his body and carried them through the proper channels to the nerves, where they are now causing him such acute torment. These wide views may please the imagination of a speculative man for a moment, when he is comfortable and safe; but they cannot stay steadily in his mind even when it is undisturbed by pain, and much less can they hold their ground when attacked by such powerful antagonists. The affections take a narrower and more natural view of their object, and by an economy better suited to the frailty of human minds they attend only to the beings around us, and are moved by whatever appears good or bad to our own small world.
Moral evil is the same case as physical evil. It cannot reasonably be supposed that remote considerations found so ineffective against the one will have more power against the other. The human mind is so made by nature that on the appearance of certain characters and actions it immediately feels approval or blame, and there are no emotions more essential to its constitution. The characters that win our approval are chiefly those contributing to the peace and security of human society, as the characters that arouse blame are chiefly those tending to public harm — from which it may reasonably be supposed that moral feelings arise, directly or indirectly, from a reflection on these opposing interests. What if philosophical meditation does establish a different opinion, that everything is right with regard to the whole, and that the qualities disturbing society are on balance as beneficial, and as much in keeping with nature's original intention, as the ones that promote its welfare more directly? Are such remote and uncertain speculations able to outweigh the feelings that arise from the natural and immediate view of things? When a man is robbed of a considerable sum, does he find his distress at the loss at all diminished by these lofty reflections? Why then should his moral resentment at the crime be supposed incompatible with them? Or why should admitting a real distinction between vice and virtue not be reconcilable with every speculative system of philosophy, just as admitting a real distinction between personal beauty and ugliness is? Both distinctions are founded in the natural feelings of the human mind, and those feelings are not to be controlled or altered by any philosophical theory whatever.
The second objection does not admit of so easy and satisfactory an answer, nor is it possible to explain clearly how God can be the mediate cause of all human actions without being the author of sin and moral wickedness. These are mysteries that mere natural and unassisted reason is very unfit to handle; and whatever system she adopts, she will find herself tangled in inextricable difficulties, and even contradictions, at every step she takes on such subjects. To reconcile the contingency of human actions with foreknowledge, or to defend absolute decrees and yet free God from being the author of sin, has so far been found to exceed all the power of philosophy. Happy if she thereby becomes aware of her own rashness in prying into these lofty mysteries — and, leaving a scene so full of obscurity and perplexity, returns with suitable modesty to her true province, the examination of ordinary life, where she will find difficulties enough to occupy her without launching out on so boundless an ocean of doubt, uncertainty and contradiction.
All our reasoning about matters of fact is founded on a kind of analogy, which leads us to expect from any cause the same events we have observed to follow from similar causes. Where the causes are exactly similar the analogy is perfect, and the inference drawn from it counts as certain: nobody who sees a piece of iron ever doubts that it will have weight and hold together, as in every other instance he has ever observed. But where the objects are not so exactly similar the analogy is less perfect and the inference less conclusive, though it still has some force in proportion to the degree of resemblance. Anatomical observations made on one animal are extended to all animals by this kind of reasoning; and certainly when the circulation of the blood is clearly proved in one creature, a frog or a fish, that creates a strong presumption that the same principle holds in all. These analogical observations can be carried further still, even into the science we are dealing with here: any theory by which we explain the operations of the understanding, or the origin and connection of the passions in man, gains extra authority if we find the same theory is needed to explain the same phenomena in every other animal. We shall try this out on the hypothesis by which we have been attempting to account for all reasoning from experience — and it is hoped that this fresh point of view will confirm everything observed so far.
First, it seems clear that animals as well as men learn a great deal from experience and infer that the same events will always follow from the same causes. By this principle they get to know the more obvious properties of external things, and gradually, from birth onwards, store up a knowledge of the nature of fire, water, earth, stones, heights, depths and so on, and of what results from them. The ignorance and inexperience of the young are plainly distinguishable here from the cunning of the old, who have learned by long observation to avoid what hurt them and to go after what gave them ease or pleasure. A horse used to the field comes to know exactly how high he can jump, and will never attempt more than he is capable of. An old greyhound will leave the more exhausting part of the chase to the younger dogs, and will place himself so as to meet the hare when she doubles back — and the guesses he makes on such an occasion are founded on nothing but his own observation and experience.
This is still clearer from the effects of training on animals, who by the proper use of rewards and punishments can be taught any course of action, even one entirely contrary to their natural instincts. Is it not experience that makes a dog fear pain when you threaten him or raise the whip? Is it not experience, too, that makes him answer to his name, and infer from such an arbitrary sound that you mean him rather than any of the others, and are calling him, when you pronounce it in a certain way and with a certain tone?
In all these cases we can see that the animal infers some fact beyond what immediately strikes his senses, and that the inference is founded entirely on past experience, the creature expecting from the object in front of him the same consequences he has always found to follow from similar objects.
Second, it is impossible that this inference of the animal's could be founded on any process of argument, by which he concludes that like events must follow like objects and that the course of nature will always be regular. For if there really are any arguments of that kind, they surely lie too deep for such imperfect understandings to notice, since it may take the utmost care and attention of a philosophical genius to discover them. So animals are not guided in these inferences by reasoning. Neither are children. Neither are most people in their ordinary actions and conclusions. Neither, for that matter, are philosophers, who in all the active parts of life are much the same as everybody else and are governed by the same maxims. Nature must have provided some other principle, more readily available and of more general application; an operation of such immense consequence in life as inferring effects from causes cannot be entrusted to the uncertain process of reasoning. If this were doubtful in the case of men, it seems beyond question in the case of animals — and once the conclusion is firmly established in the one, all the rules of analogy give us a strong presumption that it ought to be admitted universally, without exception or reserve. It is custom alone that leads animals to infer, from every object striking their senses, its usual companion, and carries their imagination from the appearance of the one to a conception of the other in the particular manner we call belief. No other explanation can be given of this operation in any of the sensitive beings we can observe, higher or lower.
But though animals learn much of their knowledge from observation, there is also much they get from nature's own hand — much that far exceeds the capacity they show on ordinary occasions, and in which they improve little or not at all with the longest practice. This we call Instinct, and we are apt to marvel at it as something quite extraordinary and inexplicable by anything human understanding can do. But our wonder will perhaps stop, or lessen, when we consider that the reasoning from experience which we share with animals, and on which the whole conduct of life depends, is itself nothing but a kind of instinct or mechanical power, working in us without our knowing it, and in its chief operations not directed by any of those relations and comparisons of ideas that are the proper objects of our intellectual faculties. The instinct is a different one, but it is still an instinct that teaches a man to avoid fire — just as much as the instinct that teaches a bird, with such exactness, the art of sitting on its eggs and the whole ordering of its nursery.
There is an argument in Dr. Tillotson's writings against the real presence which is as concise and elegant and strong as any argument could possibly be against a doctrine so little worth a serious refutation. It is acknowledged on all sides, says that learned prelate, that the authority of scripture and of tradition alike rests merely on the testimony of the apostles, who were eyewitnesses to the miracles by which our Saviour proved his divine mission. Our evidence for the truth of the Christian religion, then, is weaker than the evidence of our own senses — because even in the first authors of our religion it was no stronger, and it must obviously weaken as it passes from them to their disciples; nor can anyone place as much confidence in their testimony as in what his senses directly show him. But weaker evidence can never overthrow stronger. So even if the doctrine of the real presence were revealed in scripture as plainly as you like, it would be directly contrary to the rules of sound reasoning to assent to it. It contradicts the senses, while the scripture and tradition it is supposed to rest on carry less evidence than the senses do — considered, that is, merely as external evidence, and not brought home to each person's heart by the immediate operation of the Holy Spirit.
Nothing is so convenient as a decisive argument of this kind, which must at least silence the most arrogant bigotry and free us from its impertinent demands. I flatter myself that I have found an argument of a similar sort which, if it is sound, will be an everlasting check among the wise and learned to superstitious delusion of every kind, and consequently will be useful as long as the world lasts. For that long, I imagine, accounts of miracles and marvels will go on being found in every history, sacred and profane.
Though experience is our only guide in reasoning about matters of fact, it must be admitted that this guide is not entirely infallible and in some cases is apt to mislead us. A man in our climate who expected better weather in any week of June than in one of December would be reasoning soundly and in accordance with experience — though he may certainly turn out, in the event, to be wrong. Notice, however, that in such a case he would have no cause to complain of experience, because experience usually warns us of the uncertainty in advance, through the contrariety of events that careful observation reveals. Not all effects follow from their supposed causes with the same certainty. Some events are found in every country and every age to have been constantly joined together; others are found to be more variable and to disappoint our expectations sometimes. So in our reasoning about matters of fact there are all imaginable degrees of assurance, from the highest certainty down to the feeblest kind of moral evidence.
A wise man, therefore, proportions his belief to the evidence. Where a conclusion rests on infallible experience, he expects the event with the highest degree of assurance and treats his past experience as a full proof that the event will happen again. In other cases he proceeds more cautiously. He weighs the opposing experiments; he considers which side has the greater number behind it; he leans that way, with doubt and hesitation; and when he finally settles his judgement, the evidence amounts to no more than what we properly call probability. All probability, then, assumes an opposition of experiments and observations, where one side is found to outweigh the other and to produce a degree of evidence proportioned to the difference. A hundred instances on one side and fifty on the other give us only a doubtful expectation; whereas a hundred uniform experiments with only one contradicting them reasonably produce a fairly strong assurance. In every case we have to balance the opposing experiments where they conflict, and subtract the smaller number from the greater, to find the exact force of the stronger evidence.
To apply these principles to a particular case. There is no kind of reasoning more common, more useful, or more necessary to human life than the kind derived from the testimony of other people and the reports of eyewitnesses. One might perhaps deny that this kind of reasoning is founded on cause and effect. I shall not argue about a word. It is enough to observe that our assurance in any argument of this kind comes from nothing but our observation of how truthful human testimony generally is, and how far facts usually conform to what witnesses report. Since it is a general maxim that no objects have any discoverable connection with one another, and that all the inferences we can draw from one to another rest merely on our experience of their constant conjunction, plainly we ought not to make an exception in favour of human testimony, whose connection with any event seems in itself no more necessary than any other. If memory were not tenacious to a certain degree; if people were not generally inclined towards truth and possessed of some principle of honesty; if they were not sensitive to shame when caught in a lie — if experience had not shown these to be qualities inherent in human nature, we should never place the least confidence in human testimony. A man who is delirious, or notorious for lying and villainy, carries no authority with us at all.
And since the evidence derived from witnesses rests on past experience, it varies with that experience, and counts as either a proof or a probability according as the conjunction between a particular kind of report and a particular kind of fact has been found constant or variable. There are a number of circumstances to be taken into account in judgements of this kind, and the ultimate standard by which we settle any dispute about them always comes from experience and observation. Where the experience is not entirely uniform on one side, it brings with it an unavoidable conflict in our judgements, and the same mutual destruction of argument as in every other kind of evidence. We often hesitate over other people's reports. We balance the opposing circumstances that cause the doubt, and when we find a superiority on one side we lean that way — but still with a reduction of assurance in proportion to the force of what opposes it.
In the present case this conflict of evidence may come from several different sources: from contrary testimony; from the character or the number of the witnesses; from the manner in which they deliver their testimony; or from all of these together. We become suspicious of an alleged fact when the witnesses contradict each other; when they are few, or of doubtful character; when they have an interest in what they assert; when they give their testimony hesitantly, or on the contrary with too violent an insistence. There are many other particulars of the same kind that may weaken or destroy the force of any argument from human testimony.
Suppose, for instance, that the fact the testimony is trying to establish is of an extraordinary and marvellous kind. In that case the evidence resulting from the testimony is diminished, more or less in proportion to how unusual the fact is. The reason we place any credit in witnesses and historians is not that we perceive any connection in advance between testimony and reality, but that we are used to finding the two agree. But when the fact attested is one that has seldom come under our observation, we have a contest between two opposite experiences, of which the one destroys the other as far as its force goes, and the stronger can only act on the mind with the force that remains. The very same principle of experience that gives us a certain degree of assurance in the testimony of witnesses also gives us, in this case, another degree of assurance against the fact they are trying to establish — and from that contradiction there necessarily arises a counterpoise, and a mutual destruction of belief.
"I should not believe such a story even if Cato told it to me" was a proverbial saying in Rome, even during that philosophical patriot's lifetime. The incredibility of a fact, it was allowed, might undermine even so great an authority.
The Indian prince who refused to believe the first accounts of the effects of frost was reasoning soundly, and it naturally took very strong testimony to make him assent to facts arising from a state of nature he was unfamiliar with, and bearing so little analogy to the events he had constant and uniform experience of. They were not contrary to his experience, but they were not in keeping with it either.
But to raise the probability against the testimony of witnesses further, let us suppose that the fact they assert, instead of being merely marvellous, is genuinely miraculous; and suppose too that the testimony taken by itself amounts to a complete proof. In that case there is proof against proof, of which the stronger must prevail — but still with its force reduced in proportion to that of its opponent.
A miracle is a violation of the laws of nature; and since a firm and unalterable experience has established those laws, the proof against a miracle, from the very nature of the fact, is as complete as any argument from experience can possibly be. Why is it more than probable that all men must die; that lead cannot remain suspended in the air by itself; that fire consumes wood and is put out by water — unless it is that these events are found to agree with the laws of nature, and that preventing them would require a violation of those laws, in other words a miracle? Nothing counts as a miracle if it ever happens in the common course of nature. It is no miracle that a man apparently in good health should die suddenly, because that kind of death, though more unusual than others, has often been observed to happen. But it is a miracle that a dead man should come back to life, because that has never been observed in any age or country. There must therefore be a uniform experience against every miraculous event, or the event would not deserve the name. And since a uniform experience amounts to a proof, we have here a direct and full proof, from the nature of the fact, against the existence of any miracle — and such a proof cannot be destroyed, nor the miracle made credible, except by an opposite and stronger proof.
The plain consequence is this, and it is a general maxim worth our attention: "That no testimony is sufficient to establish a miracle, unless the testimony be of such a kind that its falsehood would be more miraculous than the fact which it endeavours to establish; and even in that case there is a mutual destruction of arguments, and the superior only gives us an assurance suitable to that degree of force which remains after deducting the inferior." When somebody tells me he has seen a dead man restored to life, I immediately consider whether it is more probable that this person is deceiving or is deceived, or that the thing he reports really happened. I weigh the one miracle against the other, and according to which I find the greater, I give my decision — and I always reject the greater miracle. Only if the falsehood of his testimony would be more miraculous than the event he relates, and not before, can he claim to command my belief.
In the reasoning so far we have supposed that the testimony a miracle rests on might possibly amount to a complete proof, and that the falsehood of that testimony would be a real marvel. But it is easy to show that we have been far too generous in the concession, and that no miraculous event has ever been established on evidence so full.
For first, there is not to be found in all of history a single miracle attested by a sufficient number of men of such unquestioned good sense, education and learning as to secure us against any delusion on their part; of such undoubted integrity as to put them beyond all suspicion of any design to deceive others; of such credit and reputation in the eyes of the world as to have a great deal to lose if they were caught in a falsehood; and at the same time attesting facts performed so publicly, and in so celebrated a part of the world, as to make detection unavoidable. All these circumstances are needed to give us full assurance in human testimony.
Second, there is a principle in human nature which, strictly examined, will be found to weaken enormously the assurance we might get from human testimony about any marvel. The maxim we usually go by in our reasoning is that objects we have no experience of resemble those we have; that what we have found most usual is always most probable; and that where arguments conflict we should prefer the one founded on the greatest number of past observations. But though we readily reject a fact that is unusual and incredible in an ordinary degree by following this rule, the mind does not always keep to it when we go further: when something utterly absurd and miraculous is asserted, the mind is if anything readier to admit it, on account of the very circumstance that ought to destroy its authority. The passions of surprise and wonder aroused by miracles are agreeable emotions, and so give us a perceptible leaning towards belief in the events that produce them. This goes so far that even people who cannot enjoy the pleasure directly, and cannot believe the miraculous events they are told about, still love to share in the satisfaction at second hand, and take pride and delight in arousing the wonder of others.
With what greediness are the miraculous accounts of travellers taken in — their descriptions of sea and land monsters, their tales of wonderful adventures, strange men and outlandish manners! But when the spirit of religion joins the love of wonder, there is an end of common sense, and human testimony in those circumstances loses all claim to authority. A religious man may be an enthusiast and imagine he sees what is not there; he may know his story is false and yet persist in it, with the best intentions in the world, for the sake of promoting so holy a cause; or even where there is no such delusion, vanity under so strong a temptation works on him more powerfully than on anyone else in any other circumstances — and self-interest just as forcibly. His hearers may not have, and usually do not have, judgement enough to sift his evidence; what judgement they have they renounce on principle in these lofty and mysterious matters; and if they were ever so willing to use it, passion and a heated imagination would upset the regularity of its working. Their credulity increases his impudence, and his impudence overpowers their credulity.
Eloquence at its highest pitch leaves little room for reason or reflection: addressing itself entirely to the fancy and the affections, it captivates willing hearers and overcomes their understanding. Happily it seldom reaches that pitch. But what a Cicero or a Demosthenes could scarcely manage with a Roman or Athenian audience, every Capuchin, every travelling or settled preacher can achieve over most of mankind, and to a greater degree, simply by touching such coarse passions.
The many instances of forged miracles and prophecies and supernatural events which in every age have either been exposed by contrary evidence or have exposed themselves by their own absurdity, sufficiently prove how strongly people incline towards the extraordinary, and ought reasonably to breed a suspicion of all reports of this kind. This is our natural way of thinking even about the most ordinary and credible events. For instance: no kind of report starts so easily or spreads so quickly, especially in country places and provincial towns, as reports about marriages — so much so that two young people of equal rank never see each other twice without the whole neighbourhood immediately marrying them off. The pleasure of telling such an interesting piece of news, of passing it on and of being the first to report it, is what spreads the information. And this is so well known that no sensible man pays attention to such reports until he finds them confirmed by stronger evidence. Do not the same passions, and others stronger still, incline most of mankind to believe and repeat all religious miracles with the greatest vehemence and assurance?
Third, it creates a strong presumption against all supernatural and miraculous reports that they are found chiefly among ignorant and barbarous nations; or that if a civilised people has ever admitted any of them, that people will be found to have received them from ignorant and barbarous ancestors, who passed them on with the inviolable sanction and authority that always attends a received opinion. When we read the earliest histories of any nation, we are apt to imagine ourselves carried into some new world where the whole frame of nature is out of joint, and every element behaves differently from the way it behaves now. Battles, revolutions, plague, famine and death are never the effect of the natural causes we experience. Marvels, omens, oracles and judgements quite obscure the few natural events mixed in among them. But since these grow thinner on every page as we advance nearer to enlightened ages, we soon learn that there is nothing mysterious or supernatural in the case, and that it all comes from the usual human leaning towards the marvellous — an inclination which may be checked from time to time by good sense and learning, but can never be thoroughly rooted out of human nature.
"It is strange," a judicious reader is apt to say on reading these wonderful historians, "that such prodigious events never happen in our own day." But it is nothing strange, I hope, that men should lie in every age. You have surely seen instances enough of that frailty. You have heard many such marvellous reports started yourself, which — being treated with scorn by everyone wise and judicious — were at last abandoned even by ordinary people. Be assured that the famous lies which have spread and flourished to such a monstrous height began in just the same way; but being sown in more suitable soil, they shot up at last into marvels almost equal to the ones they describe.
It was a shrewd policy in that false prophet Alexander — now forgotten, though once so famous — to set the first scene of his impostures in Paphlagonia, where, as Lucian tells us, the people were extremely ignorant and stupid and ready to swallow the grossest delusion. People at a distance, weak enough to think the matter worth enquiring into at all, have no way of getting better information. The stories reach them magnified by a hundred additional details. Fools are industrious in spreading the imposture, while the wise and learned are generally content to laugh at its absurdity without informing themselves of the particular facts by which it could be specifically refuted. And so the impostor just mentioned was able to proceed from his ignorant Paphlagonians to enlisting followers even among the Greek philosophers, and among men of the most eminent rank in Rome; he even engaged the attention of that wise emperor Marcus Aurelius, far enough to make him entrust the success of a military expedition to his lying prophecies.
The advantages of starting an imposture among an ignorant people are so great that even if the delusion is too gross to take in most of them — which is sometimes, though seldom, the case — it still has a much better chance of succeeding in remote countries than if the first scene had been set in a city famous for arts and knowledge. The most ignorant and barbarous of these barbarians carry the report abroad. None of their countrymen has a wide correspondence, or credit and authority enough to contradict the delusion and beat it down. Human inclination towards the marvellous has every opportunity to display itself. And so a story universally laughed out of court where it started will pass for certain a thousand miles away. Had Alexander settled in Athens, the philosophers of that renowned market of learning would immediately have spread their opinion of the matter through the whole Roman empire; and being supported by such great authority and set out with all the force of reason and eloquence, it would have opened the eyes of mankind entirely. It is true that Lucian, passing through Paphlagonia by chance, had the opportunity of performing this good office. But much as it is to be wished, it does not always happen that every Alexander meets his Lucian, ready to expose and detect his impostures.
I may add a fourth reason for reducing the authority of marvels: that there is no testimony for any of them, even those never expressly exposed, which is not opposed by an infinite number of witnesses — so that not only does the miracle destroy the credit of the testimony, but the testimony destroys itself. To make this clearer, consider that in matters of religion whatever is different is contrary, and that it is impossible that the religions of ancient Rome, of Turkey, of Siam and of China should all be established on any solid foundation. So every miracle claimed to have been worked in any of these religions — and they all abound in miracles — has as its direct purpose the establishing of the particular system it belongs to, and by the same token has the same force, though more indirectly, to overthrow every other system. In destroying a rival system it also destroys the credit of the miracles that system was founded on; so that the marvels of the different religions must be regarded as contrary facts, and the evidence for them, weak or strong, as opposed to one another. On this way of reasoning, when we believe a miracle of Muhammad or his successors, our warrant is the testimony of a few barbarous Arabs — while on the other side we have the authority of Livy, Plutarch, Tacitus, and in short of every author and witness, Greek, Chinese and Roman Catholic, who has ever recorded a miracle in his own religion. Their testimony, I say, must be regarded exactly as if they had mentioned that Muhammadan miracle and had denied it in so many words, with the same certainty they have for the miracle they do relate. The argument may look over-subtle, but it is really no different from the reasoning of a judge, who takes it that the credit of two witnesses charging someone with a crime is destroyed by the testimony of two others who say he was two hundred leagues away at the very moment the crime is supposed to have been committed.
One of the best attested miracles in all profane history is the one Tacitus reports of Vespasian, who cured a blind man in Alexandria with his spittle and a lame man with the mere touch of his foot, obeying a vision of the god Serapis, who had told them to apply to the Emperor for these miraculous cures. The story can be found in that fine historian, where every detail seems to add weight to the testimony, and could be set out at length with all the force of argument and eloquence, if anyone nowadays had an interest in pressing the evidence for that exploded and idolatrous superstition. There is the gravity, solidity, age and honesty of so great an emperor, who all his life talked familiarly with his friends and courtiers and never affected the extraordinary airs of divinity that Alexander and Demetrius assumed. There is the historian, a contemporary writer, noted for candour and truthfulness, and perhaps the greatest and most penetrating genius of all antiquity — and so free from any tendency to credulity that he lies under the opposite charge, of atheism and profanity. There are the people on whose authority he relates the miracle, of established character for judgement and truthfulness, as we may well suppose, eyewitnesses of the fact, and confirming their testimony after the Flavian family had been stripped of the empire and could no longer pay anything for a lie. Utrumque, qui interfuere, nunc quoque memorant, postquam nullum mendacio pretium — those who were present still tell both stories now, when there is no longer any reward for lying. Add to this the public nature of the facts as related, and it will appear that no evidence could well be imagined stronger for so gross and palpable a falsehood.
There is also a memorable story related by Cardinal de Retz which deserves our attention. When that intriguing politician fled into Spain to escape his enemies, he passed through Saragossa, the capital of Aragon, where he was shown in the cathedral a man who had served seven years as a doorkeeper and was well known to everyone in town who had ever worshipped at that church. For all that time he had been seen to be missing a leg — but had recovered the limb by rubbing holy oil on the stump, and the cardinal assures us that he saw him with two legs. The miracle was vouched for by all the canons of the church, and the whole town was appealed to for confirmation; and the cardinal found them, by their zealous devotion, to be thorough believers in it. Here the reporter was again a contemporary of the supposed marvel, of an incredulous and libertine character as well as of great ability; the miracle was of so singular a kind that it could scarcely be counterfeited; and the witnesses were very numerous, and all of them in a manner spectators of what they testified to. And what adds enormously to the force of the evidence, and may double our surprise, is that the cardinal himself, who tells the story, seems to give it no credit at all, and so cannot be suspected of any part in the holy fraud. He judged rightly that in order to reject a fact of this kind it was not necessary to be able to disprove the testimony exactly, and trace its falsehood through all the knavery and credulity that produced it. He knew that this was usually quite impossible at any distance of time or place, and extremely difficult even for someone immediately present, on account of the bigotry, ignorance, cunning and roguery of a great part of mankind. So he concluded, like a sound reasoner, that such evidence carried falsehood on the very face of it, and that a miracle supported by any human testimony was more properly a subject for derision than for argument.
There was surely never a greater number of miracles ascribed to one person than those recently said to have been worked in France at the tomb of the Abbé Paris, the famous Jansenist, with whose sanctity the people were so long deluded. Curing the sick, giving hearing to the deaf and sight to the blind were everywhere talked of as the usual effects of that holy tomb. But what is more extraordinary, many of the miracles were immediately proved on the spot before judges of unquestioned integrity, attested by witnesses of credit and distinction, in a learned age, and on the most eminent stage now in the world. Nor is that all: an account of them was published and distributed everywhere; and the Jesuits, though a learned body backed by the civil magistrate and determined enemies of the opinions the miracles were supposed to favour, were never able to refute or expose them in detail. Where shall we find such a number of circumstances all converging to corroborate one fact? And what have we to set against such a cloud of witnesses, except the absolute impossibility, the miraculous nature, of the events they relate? And that surely, in the eyes of all reasonable people, will be regarded as refutation enough on its own.
Is the inference sound that because some human testimony has the utmost force and authority in some cases — when it reports the battle of Philippi or Pharsalia, for instance — therefore all kinds of testimony must have equal force in all cases? Suppose the Caesarean and Pompeian factions had each claimed the victory in those battles, and the historians of each side had uniformly given the advantage to their own: how could anyone at this distance decide between them? The conflict is just as strong between the miracles reported by Herodotus or Plutarch and those handed down by Mariana, Bede, or any monkish historian.
The wise lend a very sceptical faith to any report that flatters the reporter's own passion — whether it magnifies his country, his family or himself, or chimes in with his natural inclinations in some other way. And what greater temptation is there than to appear a missionary, a prophet, an ambassador from heaven? Who would not face many dangers and difficulties to attain so lofty a character? Or if, with the help of vanity and a heated imagination, a man has first converted himself and entered seriously into the delusion — who then hesitates to use pious frauds in support of so holy and meritorious a cause?
The smallest spark may kindle the greatest flame here, because the materials are always laid ready for it. The avidum genus auricularum, the gaping crowd, take in greedily and without examination whatever soothes superstition and feeds wonder.
How many stories of this kind have in every age been detected and exploded in their infancy? How many more have been celebrated for a time and then sunk into oblivion? Where such reports are flying about, then, the explanation is obvious, and we are judging in accordance with regular experience when we account for them by the known and natural principles of credulity and delusion. And shall we, rather than resort to so natural an explanation, allow a miraculous violation of the best established laws of nature?
I need not mention how hard it is to detect a falsehood in any private or even public history, in the very place where it is supposed to have happened — much more when the scene is moved to any distance at all. Even a court of law, with all the authority and accuracy and judgement it can bring to bear, often finds itself at a loss to tell truth from falsehood in the most recent events. But the matter never comes to any conclusion at all if it is left to the ordinary method of wrangling and debate and flying rumour, especially when people's passions have taken sides.
In the infancy of a new religion the wise and learned usually think the matter too trivial to deserve their attention. And when afterwards they would gladly expose the fraud and undeceive the deluded multitude, the moment has passed, and the records and witnesses that might have cleared the matter up have perished beyond recovery.
No means of detection is left except what can be drawn from the testimony of the reporters itself; and these, though always sufficient for the judicious and knowledgeable, are usually too fine to be grasped by ordinary people.
On the whole, then, it appears that no testimony for any kind of miracle has ever amounted to a probability, much less to a proof — and that even supposing it amounted to a proof, it would be opposed by another proof, drawn from the very nature of the fact it was trying to establish. It is experience alone that gives authority to human testimony, and it is the same experience that assures us of the laws of nature. So when these two kinds of experience conflict, we have nothing to do but subtract the one from the other and adopt an opinion on one side or the other with whatever assurance the remainder gives us. But on the principle explained here, this subtraction, applied to all popular religions, amounts to a total annihilation; and therefore we may lay it down as a maxim that no human testimony can have force enough to prove a miracle and make it a sound foundation for any such system of religion.
I beg that the limits I am setting here may be noticed, when I say that a miracle can never be proved so as to be the foundation of a system of religion. For I grant that there may otherwise possibly be miracles, violations of the usual course of nature, of a kind that would admit of proof from human testimony — though perhaps it will be impossible to find any such in all the records of history. Suppose, for instance, that all authors in all languages agree that from the first of January 1600 there was a total darkness over the whole earth for eight days; suppose the tradition of this extraordinary event is still strong and lively among the people; that all travellers returning from foreign countries bring us accounts of the same tradition without the least variation or contradiction. Plainly our present philosophers, instead of doubting the fact, ought to accept it as certain and go looking for the causes it might have arisen from. The decay and dissolution of nature is an event made probable by so many analogies that any phenomenon seeming to tend towards that catastrophe comes within the reach of human testimony, if that testimony is very extensive and uniform.
But suppose all the historians who deal with England agreed that on the first of January 1600 Queen Elizabeth died; that both before and after her death she was seen by her physicians and the whole court, as is usual with people of her rank; that her successor was acknowledged and proclaimed by parliament; and that after being buried a month she appeared again, took back the throne, and governed England for three years. I confess I should be astonished at the concurrence of so many odd circumstances, but I should not have the least inclination to believe so miraculous an event. I should not doubt her supposed death, or the other public circumstances that followed it. I should only maintain that it had been staged, and that it neither was nor possibly could be real. You would object in vain that it is difficult, almost impossible, to deceive the world in a matter of such consequence; that the queen was famously wise and sound in judgement; that she could gain little or nothing by so poor a trick. All this might astonish me — but I should still reply that the knavery and folly of men are such common phenomena that I would sooner believe the most extraordinary events to have arisen from them than admit so signal a violation of the laws of nature.
But if this miracle were ascribed to some new system of religion, then — men in every age having been so much imposed on by ridiculous stories of that kind — that very circumstance would be full proof of a fraud, and enough for all sensible people not merely to reject the fact but to reject it without further examination. Though the Being to whom the miracle is ascribed is in this case Almighty, that does not make it a whit more probable, since it is impossible for us to know the attributes or actions of such a Being except from the experience we have of what he produces in the usual course of nature. This still brings us back to past observation, and obliges us to compare the instances of men violating truth in their testimony with the instances of the laws of nature being violated by miracles, in order to judge which is the more likely. And since violations of truth are more common in testimony about religious miracles than in testimony about any other matter of fact, this must greatly reduce the authority of such testimony, and make us form a general resolution never to pay it any attention, under whatever plausible pretence it may be dressed up.
Lord Bacon seems to have adopted the same principles of reasoning. "We ought," he says, "to make a collection or particular history of all monsters and prodigious births or productions, and in a word of everything new, rare, and extraordinary in nature. But this must be done with the most severe scrutiny, lest we depart from truth. Above all, every relation must be considered as suspicious, which depends in any degree upon religion, as the prodigies of Livy: And no less so, everything that is to be found in the writers of natural magic or alchemy, or such authors, who seem, all of them, to have an unconquerable appetite for falsehood and fable."
I am the better pleased with the method of reasoning set out here because I think it may serve to confound those dangerous friends, or disguised enemies, of the Christian Religion who have undertaken to defend it on the principles of human reason. Our most holy religion is founded on Faith, not on reason; and it is a sure way of exposing it to put it to a trial it is by no means fitted to endure. To make this plainer, let us examine the miracles related in scripture — and so as not to lose ourselves in too wide a field, let us confine ourselves to the ones in the Pentateuch, which we shall examine on the principles of these supposed Christians, not as the word or testimony of God himself, but as the work of a merely human writer and historian. Here, then, we have first to consider a book presented to us by a barbarous and ignorant people, written in an age when they were still more barbarous, and in all probability long after the events it relates, corroborated by no concurring testimony, and resembling the fabulous accounts every nation gives of its own origin. On reading this book we find it full of marvels and miracles. It gives an account of a state of the world and of human nature entirely different from the present; of our fall from that state; of a human lifespan stretched to nearly a thousand years; of the destruction of the world by a flood; of the arbitrary choice of one people as the favourites of heaven, that people being the author's own countrymen; of their deliverance from slavery by the most astonishing marvels imaginable. I ask anyone to lay his hand on his heart and, after serious consideration, declare whether he thinks the falsehood of such a book, supported by such testimony, would be more extraordinary and miraculous than all the miracles it relates — which is nevertheless what is required for it to be accepted, by the measures of probability established above.
What has been said of miracles applies without any change to prophecies; and indeed all prophecies are real miracles, and only as such can be admitted as proofs of any revelation. If foretelling future events did not exceed the capacity of human nature, it would be absurd to use any prophecy as an argument for a divine mission. So on the whole we may conclude that the Christian Religion not only was attended with miracles at first, but cannot to this day be believed by any reasonable person without one. Mere reason is not enough to convince us of its truth; and whoever is moved by Faith to assent to it is conscious of a continued miracle in his own person, which overturns all the principles of his understanding and gives him a determination to believe what is most contrary to custom and experience.
I was recently in conversation with a friend who loves sceptical paradoxes. He put forward a good many principles I cannot approve of at all; but since they seem curious, and bear some relation to the chain of reasoning running through this enquiry, I shall set them down here from memory as accurately as I can, and submit them to the reader's judgement.
Our conversation began with my admiring the remarkable good fortune of philosophy. Since philosophy needs complete liberty above every other privilege, and flourishes chiefly on the free clash of opinions, it was lucky to be born in an age and country of freedom and toleration, and never to have been cramped, even in its most extravagant principles, by any creed or penal statute. Apart from the banishment of Protagoras and the death of Socrates — and the second of those was partly for other reasons — there is scarcely an instance in ancient history of the bigoted jealousy the present age is so infested with. Epicurus lived at Athens to a great age in peace and quiet. Epicureans were even admitted to the priesthood and allowed to officiate at the altar in the most sacred rites of the established religion. And the wisest of the Roman emperors handed out public pensions and salaries equally to professors of every philosophical sect. How necessary that sort of treatment was to philosophy in her early youth is easy to see if we reflect that even now, when she may be supposed hardier and more robust, she bears with great difficulty the harsh winds of slander and persecution that blow on her.
You admire as the special good fortune of philosophy, says my friend, what really follows from the natural course of things and is unavoidable in every age and nation. This stubborn bigotry you complain of as so fatal to philosophy is really her own child, who — after allying himself with superstition — separates himself entirely from his parent's interest and becomes her bitterest enemy and persecutor. Speculative religious dogmas, the present occasion of such furious dispute, could not possibly have been conceived or accepted in the early ages of the world, when mankind, being entirely illiterate, formed an idea of religion suited to their weak grasp, and made up their sacred doctrines chiefly of the sort of tales that are objects of traditional belief rather than of argument. So once the first alarm was over, raised by the new paradoxes of the philosophers, those teachers seem ever afterwards throughout antiquity to have lived in great harmony with the established superstition, and to have divided mankind fairly between them: philosophy claiming the learned and wise, superstition keeping the common and unlettered.
It seems, then, said I, that you leave politics out of the question entirely, and never suppose that a wise magistrate can be justly wary of certain doctrines of philosophy — those of Epicurus, for instance, which by denying a divine existence, and consequently a providence and a future state, seem largely to loosen the ties of morality, and may for that reason be thought dangerous to the peace of civil society.
I know, he replied, that in fact these persecutions have never in any age proceeded from calm reason, or from experience of philosophy's harmful consequences, but have arisen entirely from passion and prejudice. But what if I went further and asserted that if Epicurus had been accused before the people by any of the sycophants or informers of the day, he could easily have defended himself, and proved his philosophical principles as wholesome as those of the opponents who were so eager to expose him to public hatred?
I wish, said I, you would try your eloquence on so extraordinary a topic, and make a speech for Epicurus that would satisfy — not the mob of Athens, if you will allow that ancient and polished city to have contained a mob, but the more philosophical part of his audience, the part that could be supposed capable of following his arguments.
That would not be difficult on those terms, he replied. If you like, I shall suppose myself Epicurus for a moment, and let you stand for the Athenian people, and deliver you such a speech as will fill the whole voting urn with white beans and leave not a single black one to gratify the malice of my adversaries.
Very well. Please proceed on those suppositions.
I come here, Athenians, to justify before your assembly what I have maintained in my school; and I find myself charged by furious antagonists instead of reasoning with calm and dispassionate enquirers. Your deliberations, which by rights should be directed to questions of public good, are being diverted into speculative philosophy, and these magnificent but perhaps fruitless enquiries are taking the place of your more ordinary but more useful business. So far as it lies with me, I shall prevent this abuse. We shall not dispute here about the origin and government of worlds. We shall only ask how far such questions concern the public interest. And if I can persuade you that they are entirely irrelevant to the peace of society and the security of government, I hope you will send us straight back to our schools, to examine at leisure the most sublime but also the most speculative question in all philosophy.
The religious philosophers, not satisfied with the tradition of your forefathers and the doctrine of your priests — in which I willingly acquiesce — indulge a rash curiosity in seeing how far they can establish religion on the principles of reason; and so they arouse, rather than satisfy, the doubts that naturally arise from a searching enquiry. They paint in the most magnificent colours the order, beauty and wise arrangement of the universe, and then ask whether so glorious a display of intelligence could have come from a chance collision of atoms, or whether accident could produce what the greatest genius can never sufficiently admire. I shall not examine the soundness of this argument. I shall allow it to be as solid as my accusers could wish. It is enough if I can prove, from that very reasoning, that the question is entirely speculative, and that when in my philosophical enquiries I deny a providence and a future state, I am not undermining the foundations of society but advancing principles which my accusers themselves, arguing consistently from their own premises, must allow to be sound.
You, then, who accuse me, have acknowledged that the chief or only argument for a divine existence — which I have never questioned — is drawn from the order of nature, where there appear such marks of intelligence and design that you think it extravagant to assign as its cause either chance or the blind force of matter. You allow that this is an argument from effects to causes. From the order of the work, you infer that there must have been planning and forethought in the workman. If you cannot make that out, you allow that your conclusion fails; and you do not claim to establish the conclusion any more widely than the phenomena of nature will justify. These are your own concessions. I ask you to mark the consequences.
When we infer a particular cause from an effect, we must proportion the one to the other, and can never be allowed to attribute to the cause any qualities beyond what are exactly sufficient to produce the effect. A ten-ounce weight raised in a scale may prove that the counterbalancing weight exceeds ten ounces, but can never give any reason to think it exceeds a hundred. If the cause assigned to an effect is not enough to produce it, we must either reject that cause or add to it whatever will bring it into proportion with the effect. But if we attribute further qualities to it, or claim it capable of producing other effects, we are merely indulging in conjecture, and arbitrarily supposing qualities and powers without reason or warrant.
The same rule holds whether the cause assigned is brute unconscious matter or a rational intelligent being. If the cause is known only through the effect, we ought never to attribute to it any qualities beyond what are precisely needed to produce that effect; nor can we by any rules of sound reasoning turn back from the cause and infer other effects from it, beyond the ones by which alone it is known to us. Nobody could tell, merely from seeing one of Zeuxis's paintings, that he was also a sculptor or an architect, and no less skilful in stone and marble than in colours. The talents and taste displayed in the particular work in front of us — those we may safely conclude the workman possessed. The cause must be proportioned to the effect; and if we proportion it exactly, we shall never find in it any qualities that point further, or allow any inference about some other design. Such qualities would have to be something beyond what is merely needed to produce the effect we are examining.
Granting, then, that the gods are the authors of the existence and order of the universe, it follows that they possess exactly that degree of power, intelligence and benevolence which appears in their workmanship — but nothing further can ever be proved, unless we call in exaggeration and flattery to make up for the shortfall in argument. So far as traces of any attribute appear at present, so far we may conclude that attribute exists. Supposing further attributes is mere hypothesis; and still more so is supposing that in distant regions of space or periods of time there has been or will be a more magnificent display of these attributes, and a scheme of administration better suited to such imaginary virtues. We can never be allowed to climb from the universe, the effect, up to Jupiter, the cause, and then climb down again to infer some new effect from that cause — as if the present effects alone were not entirely worthy of the glorious attributes we ascribe to that deity. Since our knowledge of the cause comes solely from the effect, the two must be exactly fitted to each other, and the one can never point to anything beyond, or be the foundation of any new conclusion.
You find certain phenomena in nature. You look for a cause, an author. You imagine you have found him. Then you become so enamoured of this offspring of your own brain that you cannot believe he would not produce something greater and more perfect than the present state of things, which is so full of evil and disorder. You forget that this supreme intelligence and benevolence is entirely imaginary, or at least has no foundation in reason, and that you have no grounds for attributing to him any qualities but the ones you can see he has actually exerted in what he has made. So let your gods, philosophers, be suited to the present appearance of nature — and do not presume to alter that appearance by arbitrary suppositions, in order to fit it to the attributes you are so fond of ascribing to your deities.
When priests and poets, backed by your authority, Athenians, talk of a golden or silver age preceding the present state of vice and misery, I listen with attention and reverence. But when philosophers, who claim to disregard authority and cultivate reason, deliver the same discourse, I confess I do not pay them the same submissive deference. I ask: who carried them up into the heavens, who admitted them to the councils of the gods, who opened the book of fate to them, that they should so rashly assert that their deities have carried out, or will carry out, any purpose beyond what has actually appeared? If they tell me they climbed by the gradual ascent of reason, drawing inferences from effects to causes, I still insist that they helped reason's ascent along with the wings of imagination — otherwise they could not have switched the direction of their inference like this and argued from causes to effects, assuming that a more perfect production than the present world would better suit such perfect beings as the gods, and forgetting that they have no reason to ascribe to those beings any perfection that cannot be found in the present world.
Hence all the fruitless industry spent on explaining away the ugly appearances of nature and saving the honour of the gods, while we are obliged to acknowledge the reality of the evil and disorder the world so abounds in. The obstinate and intractable qualities of matter, we are told, or the need to observe general laws, or some such reason, is the sole thing that restrained the power and benevolence of Jupiter and obliged him to create mankind and every sentient creature so imperfect and so unhappy. So those attributes, it seems, are taken for granted beforehand, in their fullest extent. And on that assumption I grant that such conjectures may perhaps pass as plausible solutions to the ugly phenomena. But still I ask: why take the attributes for granted? Why attribute to the cause any qualities but the ones that actually appear in the effect? Why torture your brain justifying the course of nature on assumptions which, for all you know, may be entirely imaginary, and of which no trace at all is to be found in the course of nature?
The religious hypothesis, then, must be regarded only as a particular way of accounting for the visible phenomena of the universe; and no sound reasoner will ever presume to infer a single new fact from it, or alter or add to the phenomena in any particular. If you think the appearance of things proves such causes, you are entitled to draw a conclusion about the existence of those causes. On subjects so complicated and lofty, everyone should be allowed the liberty of conjecture and argument. But there you ought to stop. If you turn round and, arguing from your inferred causes, conclude that some other fact has existed or will exist in the course of nature which would display those attributes more fully, then I must warn you that you have abandoned the method of reasoning proper to this subject, and have certainly added something to the attributes of the cause beyond what appears in the effect — otherwise you could never, with any sense or propriety, add anything to the effect in order to make it more worthy of the cause.
Where, then, is the odiousness of the doctrine I teach in my school — or rather, that I examine in my gardens? Or what is there in this whole question that touches in the least on the security of good morals or the peace and order of society?
I deny a providence, you say, and a supreme governor of the world, who directs the course of events and punishes the wicked with disgrace and disappointment while rewarding the virtuous with honour and success in all they undertake. But surely I do not deny the course of events itself, which lies open to everyone's inspection. I acknowledge that in the present order of things, virtue brings more peace of mind than vice and meets with a warmer reception from the world. I am aware that on the past experience of mankind, friendship is the chief joy of human life and moderation the only source of tranquillity. I never hesitate between the virtuous and the vicious course of life, but am well aware that to a well-disposed mind every advantage lies on the side of the first. And what more can you say, granting all your suppositions and reasonings? You tell me, certainly, that this arrangement of things proceeds from intelligence and design. But whatever it proceeds from, the arrangement itself — on which our happiness or misery, and consequently our conduct in life, depend — is still the same. It is still as open to me as to you to regulate my behaviour by my experience of past events. And if you maintain that, since a divine providence and a supreme distributive justice in the universe are admitted, I ought to expect some more particular reward of the good and punishment of the bad beyond the ordinary course of events, I find here the very fallacy I have already been trying to expose. You persist in imagining that if we grant the divine existence you argue for so earnestly, you may safely infer consequences from it, and add something to the experienced order of nature by arguing from the attributes you ascribe to your gods. You seem to forget that all your reasoning on this subject can only run from effects to causes, and that every argument running from causes to effects must necessarily be a gross fallacy — since it is impossible for you to know anything of the cause except what you have already, not inferred but fully discovered, in the effect.
But what must a philosopher think of those empty reasoners who, instead of treating the present scene of things as the sole object of their attention, so far reverse the whole course of nature as to make this life a mere passage to something further — a porch leading to a greater and quite different building, a prologue serving only to introduce the play and give it more grace? Where do you suppose such philosophers get their idea of the gods? From their own fancy, surely. For if they got it from the present phenomena, it would never point to anything beyond them, but would have to be exactly fitted to them. That the divinity may possibly have attributes we have never seen exerted, and may be governed by principles of action we cannot see satisfied — all this will be freely granted. But it remains mere possibility and hypothesis. We can never have reason to infer any attribute in him, or any principle of action, except so far as we know it to have been exerted and satisfied.
Are there any marks of a distributive justice in the world? If you answer yes, I conclude that since justice does exert itself here, it is satisfied. If you answer no, I conclude that you have no reason to attribute justice, in our sense of the word, to the gods at all. And if you take a middle course and say that the justice of the gods exerts itself at present in part but not to its full extent, I answer that you have no reason to give it any particular extent, but only as far as you see it exert itself at present.
So I bring the dispute to a short issue with my opponents, Athenians. The course of nature lies open to my contemplation as much as to theirs. The experienced train of events is the great standard by which we all regulate our conduct. Nothing else can be appealed to in the field or in the senate. Nothing else ought ever to be heard of in the school or the study. Our limited understanding tries in vain to break through boundaries too narrow for our fond imagination. When we argue from the course of nature and infer a particular intelligent cause, which first bestowed order on the universe and still preserves it, we are adopting a principle that is both uncertain and useless. Uncertain, because the subject lies entirely beyond the reach of human experience. Useless, because our knowledge of this cause being derived entirely from the course of nature, we can never by the rules of sound reasoning come back from the cause with any new inference, or set up any new principles of conduct by making additions to the ordinary experienced course of nature.
I observe, said I, finding he had finished his speech, that you do not neglect the tricks of the old demagogues; and having been kind enough to make me stand for the people, you work your way into my favour by adopting principles you know I have always had a particular attachment to. But even granting you experience as the only standard of our judgement on this and every other question of fact — which I do think it ought to be — I have no doubt that it is possible, from that very experience you appeal to, to refute the reasoning you have put into the mouth of Epicurus. If you saw a half-finished building, surrounded by heaps of brick and stone and mortar and all the tools of masonry, could you not infer from the effect that it was a work of design? And could you not turn back from that inferred cause to infer new additions to the effect, and conclude that the building would soon be finished and receive all the further improvements art could give it? If you saw the print of a single human foot on the seashore, you would conclude that a man had passed that way, and that he had also left the print of the other foot, though the rolling sand or the water had wiped it out. Why then do you refuse to allow the same method of reasoning about the order of nature? Regard the world and the present life as merely an unfinished building, from which you can infer a superior intelligence; and arguing from that superior intelligence, which can leave nothing imperfect, why may you not infer a more finished plan, which will reach its completion at some distant point of space or time? Are these two methods of reasoning not exactly alike? And on what pretext can you accept the one while rejecting the other?
The infinite difference between the two subjects, he replied, is foundation enough for the difference in my conclusions. In works of human skill and contrivance it is legitimate to move from the effect to the cause, and then back from the cause to form new inferences about the effect, and to consider the changes it has probably undergone or may still undergo. But what is the foundation of that method of reasoning? Plainly this: that man is a being we know by experience, whose motives and designs we are acquainted with, and whose projects and inclinations hang together in a certain way, according to the laws nature has established for governing such a creature. So when we find that some work has come from human skill and industry, since we are acquainted with the animal from other sources, we can draw a hundred inferences about what may be expected of him — and all those inferences will be founded on experience and observation. But if we knew man only from the single work in front of us, it would be impossible to argue this way, because our knowledge of every quality we ascribe to him would in that case come from the product itself, so that it could not possibly point to anything beyond, or be the foundation of any new inference. The print of a foot in the sand, taken alone, can only prove that there was some shape fitted to it that made it; but the print of a human foot also proves, from our other experience, that there was probably another foot which left its impression too, though time or accident has effaced it. Here we do climb from the effect to the cause and then descend again from the cause to infer alterations in the effect — but this is not a continuation of the same simple chain of reasoning. We are bringing in a hundred other experiences and observations about the usual shape and limbs of that species of animal, and without them the argument would have to be counted a fallacy.
It is not the same with our reasoning from the works of nature. God is known to us only through what he has produced, and is a single being in the universe, not included in any species or genus from whose experienced attributes we could infer by analogy any attribute in him. Since the universe shows wisdom and goodness, we infer wisdom and goodness. Since it shows a particular degree of these perfections, we infer a particular degree of them, precisely matched to the effect we are examining. But further attributes, or further degrees of the same attributes, we can never be authorised to infer by any rules of sound reasoning. And without some such licence of supposition it is impossible for us to argue from the cause, or to infer any change in the effect beyond what has come directly under our observation. A greater good produced by this Being would still only prove a greater degree of goodness; a more impartial distribution of rewards and punishments would only follow from a greater regard for justice. Every supposed addition to the works of nature makes an addition to the attributes of the Author of nature — and consequently, being entirely unsupported by any argument, can never be admitted as anything but conjecture.
The great source of our error on this subject, and of the unbounded licence of conjecture we indulge in, is that we tacitly put ourselves in the place of the Supreme Being, and conclude that on every occasion he will behave as we ourselves in his situation would have thought reasonable. But quite apart from the fact that the ordinary course of nature may convince us that almost everything is regulated by principles very different from ours — quite apart from that, it must plainly be contrary to all rules of analogy to reason from the intentions of men to those of a Being so different and so much superior. In human nature there is a certain experienced coherence of designs and inclinations, so that when some fact has revealed one intention of a man's, it can often be reasonable to infer another from experience, and to draw a long chain of conclusions about his past or future conduct. But this method of reasoning can never apply to a Being so remote and incomprehensible, who bears far less analogy to any other being in the universe than the sun does to a wax candle, and who reveals himself only in a few faint traces, beyond which we have no authority to ascribe him any attribute at all. What we imagine to be a superior perfection may really be a defect. And even if it were a perfection beyond question, ascribing it to the Supreme Being where it does not appear to have been fully exerted in his works smacks more of flattery than of sound philosophy. So all the philosophy in the world, and all the religion — which is only a kind of philosophy — will never be able to carry us beyond the usual course of experience, or give us measures of conduct different from the ones that reflection on ordinary life supplies. No new fact can ever be inferred from the religious hypothesis; no event foreseen or foretold; no reward or punishment expected or dreaded, beyond what is already known from practice and observation. So my defence of Epicurus still stands, and the political interests of society have no connection with philosophical disputes about metaphysics and religion.
There is still one point, I replied, that you seem to have overlooked. Even granting your premises, I must deny your conclusion. You conclude that religious doctrines can have no influence on life because they ought to have none — never considering that people do not reason the way you do, but draw many consequences from a belief in a divine existence, and suppose that God will inflict punishments on vice and bestow rewards on virtue beyond what appears in the ordinary course of nature. Whether their reasoning is sound or not makes no difference. Its influence on their life and conduct is the same either way. And those who try to rid them of such prejudices may for all I know be good reasoners, but I cannot allow them to be good citizens, since they release men from one restraint on their passions, and make breaking the laws of society easier and safer in that one respect.
After all, I may perhaps agree with your general conclusion in favour of liberty, though on different premises from the ones you try to found it on. I think the state ought to tolerate every principle of philosophy; and there is no instance of any government suffering in its political interests through such indulgence. There is no enthusiasm among philosophers; their doctrines are not very alluring to the people; and no restraint can be put on their reasoning that would not be dangerous to the sciences, and even to the state, by opening the way for persecution on points in which most people are far more deeply concerned.
But there is one difficulty about your main topic, I went on, which I shall simply put to you without pressing it, for fear of leading us into reasoning of too delicate a kind. In a word: I much doubt whether it is possible for a cause to be known only by its effect, as you have supposed throughout, or to be of so singular a nature that it has no parallel and no resemblance to any other cause or object that has ever come under our observation. It is only when two species of object are found to be constantly conjoined that we can infer the one from the other; and if an effect were presented that was entirely singular, and could not be brought under any known species, I do not see that we could form any conjecture at all about its cause. If experience and observation and analogy really are the only guides we can reasonably follow in inferences of this kind, then both the effect and the cause must bear some resemblance to other effects and causes we know, and have found joined together in many instances. I leave you to work out the consequences of this principle for yourself. I shall only observe that since the opponents of Epicurus always take the universe — an effect quite singular and unparalleled — to be proof of a God, a cause no less singular and unparalleled, your reasoning on that supposition seems at the least to deserve our attention. There is, I admit, some difficulty about how we can ever return from the cause to the effect, and by reasoning from our ideas of the first infer any alteration in the second, or any addition to it.
No subject has produced a greater quantity of philosophical reasoning than the existence of God and the refutation of the fallacies of Atheists — and yet the most religious philosophers still dispute whether any man could be blind enough to be a speculative atheist. How are we to reconcile these contradictions? The knights errant who wandered about ridding the world of dragons and giants never entertained the slightest doubt that those monsters existed.
The Sceptic is another enemy of religion who naturally provokes the indignation of every divine and every graver philosopher — though it is certain that nobody has ever met such an absurd creature, or talked with a man who had no opinion or principle at all on any subject of action or speculation. This raises a very natural question: what is meant by a sceptic? And how far is it possible to push these philosophical principles of doubt?
There is a kind of scepticism antecedent to all study and philosophy, much recommended by Descartes and others as a sovereign preservative against error and hasty judgement. It urges a universal doubt, not only of all our former opinions and principles but of our very faculties — whose reliability, they say, we must establish by a chain of reasoning deduced from some original principle that could not possibly be deceptive. But there is no such original principle with any privilege over others that are self-evident and convincing; and even if there were, we could not advance a single step beyond it except by using the very faculties we are supposed to distrust already. So Cartesian doubt, if any human creature could ever actually attain it — which plainly nobody can — would be entirely incurable, and no reasoning could ever bring us to a state of conviction about anything.
It must be admitted, however, that this kind of scepticism, in a more moderate form, can be understood in a very reasonable sense, and is a necessary preparation for the study of philosophy: it preserves a proper impartiality in our judgements and weans the mind from the prejudices we may have absorbed from our education or from rash opinion. To begin with clear and self-evident principles, to advance by cautious and sure steps, to review our conclusions frequently and examine all their consequences carefully — these are the only methods by which we can ever hope to reach truth and attain any stability in our conclusions, even though by these means our systems will grow both slowly and not far.
There is another kind of scepticism, consequent to science and enquiry, arising when men suppose they have discovered either that their mental faculties are entirely unreliable, or that they are unfit to reach any settled conclusion on the curious subjects of speculation they are usually employed on. Even our senses are brought into dispute by a certain sort of philosopher, and the maxims of ordinary life are subjected to the same doubt as the deepest conclusions of metaphysics and theology. Since these paradoxical doctrines — if they can be called doctrines — are to be met with in some philosophers, and refutations of them in several, they naturally rouse our curiosity about the arguments they may rest on.
I need not dwell on the more familiar objections the sceptics of every age have raised against the evidence of the senses: those drawn from the imperfection and unreliability of our organs on countless occasions, the bent appearance of an oar in water, the different look of objects at different distances, the double image produced by pressing one eye, and many other appearances of the kind. These sceptical points are enough only to prove that the senses are not to be relied on implicitly by themselves, and that we must correct their evidence by reason, and by considerations drawn from the nature of the medium, the distance of the object, and the condition of the organ, in order to make them, within their own sphere, proper criteria of truth and falsehood. There are other, deeper arguments against the senses that do not admit of so easy a solution.
It seems clear that men are carried by a natural instinct to put their faith in their senses, and that without any reasoning — almost before we can use reason at all — we always suppose an external universe which does not depend on our perceiving it, and would exist even if we and every sentient creature were annihilated. Animals are governed by the same opinion, and keep this belief in external objects in all their thoughts and actions.
It also seems clear that when men follow this blind and powerful instinct of nature, they always take the very images presented by the senses to be the external objects themselves, and never suspect that the first are nothing but representations of the second. This table, which we see to be white and feel to be hard, is believed to exist independently of our perceiving it, and to be something outside the mind that perceives it. Our presence does not confer being on it; our absence does not annihilate it. It keeps its existence uniform and entire, regardless of the situation of the intelligent beings who perceive it.
But this universal and primary opinion of all mankind is soon destroyed by the slightest philosophy, which teaches us that nothing can ever be present to the mind but an image or perception, and that the senses are only the entrances through which these images are conveyed, without being able to produce any direct commerce between the mind and the object. The table we see seems to shrink as we move away from it — but the real table, which exists independently of us, undergoes no change; so it was nothing but its image that was present to the mind. These are the obvious dictates of reason, and no reflecting person has ever doubted that the existences we have in view when we say this house and that tree are nothing but perceptions in the mind, fleeting copies of other existences that remain uniform and independent.
So reasoning forces us to contradict the primary instincts of nature and adopt a new system regarding the evidence of the senses. But here philosophy finds herself extremely embarrassed when she tries to justify this new system and answer the objections of the sceptics. She can no longer plead the infallible and irresistible instinct of nature, for that led us to a quite different system, one now admitted to be unreliable and even mistaken. And to justify this supposed philosophical system by a chain of clear and convincing argument, or even by anything that looks like an argument, exceeds all human capacity.
By what argument can it be proved that the mind's perceptions must be caused by external objects entirely different from them, though resembling them, if that is even possible — and could not arise either from the energy of the mind itself, or from the suggestion of some invisible and unknown spirit, or from some cause still more unknown to us? It is acknowledged that in fact many of these perceptions do not arise from anything external, as in dreams and madness and other illnesses. And nothing could be more inexplicable than the way a body could act on a mind so as to convey an image of itself to a substance supposed to be of so different and even contrary a nature.
It is a question of fact whether the perceptions of the senses are produced by external objects resembling them. How is this question to be settled? By experience, surely, as all other questions of the kind are. But here experience is, and must be, entirely silent. The mind never has anything present to it but the perceptions, and cannot possibly get any experience of their connection with objects. So the supposition of such a connection has no foundation in reasoning at all.
To fall back on the truthfulness of the supreme Being in order to prove the truthfulness of our senses is surely a very unexpected detour. If his truthfulness were involved in the matter at all, our senses would be entirely infallible, since it is not possible for him ever to deceive. Not to mention that once the external world has been called into question, we shall be at a loss to find any arguments by which to prove the existence of that Being, or any of his attributes.
This, then, is a subject on which the deeper and more philosophical sceptics will always triumph, when they set out to introduce a universal doubt into every field of human knowledge. Do you follow the instincts of nature, they may say, in trusting the evidence of the senses? But those instincts lead you to believe that the perception, the sensible image, is itself the external object. Do you disown that principle in order to embrace the more rational opinion that perceptions are only representations of something external? Then you have departed from your natural inclinations and your most obvious feelings — and still cannot satisfy your reason, which can never find any convincing argument from experience to prove that perceptions are connected with any external object at all.
There is another sceptical point of the same kind, drawn from the deepest philosophy, which might deserve our attention if it were worth diving so deep to find arguments that serve so little serious purpose. It is universally granted by modern enquirers that all the perceptible qualities of objects — hard, soft, hot, cold, white, black and the rest — are merely secondary, and do not exist in the objects themselves but are perceptions of the mind, with no external original that they represent. If this is granted for the secondary qualities, it must follow for the supposed primary qualities of extension and solidity too; the latter have no better claim to the name than the former. The idea of extension is acquired entirely from sight and touch; and if all the qualities perceived by the senses are in the mind and not in the object, the same conclusion must reach the idea of extension, which depends wholly on those sensible ideas. Nothing can save us from this conclusion except asserting that the ideas of primary qualities are reached by Abstraction — an opinion which, examined closely, turns out to be unintelligible and even absurd. An extension that is neither tangible nor visible cannot possibly be conceived; and a tangible or visible extension that is neither hard nor soft, black nor white, is equally beyond human conception. Let anyone try to conceive a triangle in general, which is neither Isosceles nor Scalene and has no particular length or proportion of sides, and he will soon see the absurdity of all the scholastic notions about abstraction and general ideas.
So the first philosophical objection to the evidence of the senses, and to belief in external existence, is that such a belief, if it rests on natural instinct, is contrary to reason, and if it is referred to reason, is contrary to natural instinct — while carrying no rational evidence with it that would convince an impartial enquirer. The second objection goes further and presents the belief as contrary to reason outright, at least if it is a principle of reason that all sensible qualities are in the mind and not in the object. Strip matter of all its intelligible qualities, primary and secondary alike, and you virtually annihilate it, leaving only a certain unknown, inexplicable something as the cause of our perceptions — a notion so imperfect that no sceptic will think it worth arguing against.
It may look like a very extravagant attempt for the sceptics to try to destroy reason by argument and reasoning; yet that is the grand aim of all their enquiries. They try to find objections both to our abstract reasonings and to those concerning matter of fact.
The chief objection to all abstract reasoning comes from the ideas of space and time — ideas which in ordinary life, viewed carelessly, are perfectly clear, but which under the scrutiny of the deeper sciences (and they are the chief object of those sciences) yield principles that seem full of absurdity and contradiction. No priestly dogma, invented on purpose to tame the rebellious reason of mankind, ever shocked common sense more than the doctrine of the infinite divisibility of extension, with all its consequences, as they are pompously set out by every geometer and metaphysician with a kind of triumph. A real quantity infinitely smaller than any finite quantity, containing quantities infinitely smaller than itself, and so on for ever: this is a structure so bold and prodigious that it is too heavy for any supposed demonstration to hold up, because it shocks the clearest and most natural principles of human reason. But what makes the matter more extraordinary is that these seemingly absurd opinions are supported by the clearest and most natural chain of reasoning, and it is not possible for us to allow the premises without admitting the consequences. Nothing could be more convincing than all the conclusions about the properties of circles and triangles — and yet once those are accepted, how can we deny that the angle of contact between a circle and its tangent is infinitely smaller than any angle made by straight lines; that as you increase the diameter of the circle without limit, this angle of contact grows smaller without limit; and that the angle of contact between other curves and their tangents may be infinitely smaller still than any circle's, and so on for ever? The demonstration of these principles seems as unexceptionable as the one proving that the three angles of a triangle equal two right angles, though the latter opinion is natural and easy and the former is big with contradiction. Reason here seems thrown into a kind of amazement and suspense which, without any sceptic's prompting, gives her a distrust of herself and of the ground she stands on. She sees a full light illuminating certain places — but that light borders on the profoundest darkness, and between the two she is so dazzled and confounded that she can scarcely pronounce with certainty on anything at all.
The absurdity of these bold pronouncements of the abstract sciences becomes, if anything, still more palpable with time than with extension. An infinite number of real parts of time, passing in succession and used up one after another, looks like so evident a contradiction that no man whose judgement has not been corrupted rather than improved by the sciences could ever, one would think, bring himself to admit it.
Yet reason must remain restless even about the scepticism these apparent contradictions drive her into. How any clear, distinct idea can contain features contradicting itself, or contradicting some other clear, distinct idea, is absolutely incomprehensible, and is perhaps as absurd as any proposition that can be formed. So nothing can be more sceptical, or fuller of doubt and hesitation, than this scepticism itself, arising as it does out of some of the paradoxical conclusions of geometry.
The sceptical objections to moral evidence, to reasoning about matters of fact, are either popular or philosophical. The popular ones are drawn from the natural weakness of human understanding; from the contradictory opinions held in different ages and nations; from the way our judgement varies in sickness and health, youth and age, prosperity and adversity; from the perpetual self-contradiction of each individual's opinions; and other points of that kind. There is no need to dwell on this. These objections are weak. Since in ordinary life we reason about fact and existence at every moment, and could not possibly survive without continually using this kind of argument, no popular objection drawn from it can be enough to destroy that evidence. The great overthrower of Pyrrhonism, of the excessive principles of scepticism, is action, and employment, and the occupations of ordinary life. These principles may flourish and triumph in the schools, where it is indeed difficult if not impossible to refute them. But as soon as they leave the shade, and are set against the more powerful principles of our nature by the presence of real objects that stir our passions, they vanish like smoke and leave the most determined sceptic in the same condition as the rest of us.
So the sceptic had better keep to his proper sphere and set out the philosophical objections, which come from deeper researches. Here he seems to have ample grounds for triumph. He rightly insists that all our evidence for any matter of fact lying beyond the testimony of sense or memory is drawn entirely from cause and effect; that we have no idea of that relation except of two objects which have frequently been found conjoined; that we have no argument to convince us that objects frequently conjoined in our experience will also be conjoined in the same way in other cases; and that nothing leads us to this inference but custom, a certain instinct of our nature, which is admittedly hard to resist, but which like other instincts may be deceptive. While the sceptic presses these points, he shows his strength — or rather, in truth, his own weakness and ours — and seems, for the moment at least, to destroy all conviction. These arguments could be set out at greater length, if any lasting good to society could ever be expected to come of them.
For here is the chief and most confounding objection to excessive scepticism: that no lasting good can ever come of it, so long as it retains its full force. We need only ask such a sceptic what he means, and what he proposes by all these curious researches. He is immediately at a loss and does not know what to answer. A Copernican or a Ptolemaist, each supporting his own system of astronomy, may hope to produce a conviction in his audience that will last. A Stoic or an Epicurean puts forward principles which may not last, but which do have an effect on conduct. But a Pyrrhonian cannot expect his philosophy to have any constant influence on the mind — or that if it did, the influence would be good for society. On the contrary, he must acknowledge, if he will acknowledge anything, that all human life would perish if his principles universally and steadily prevailed. All talk, all action would cease immediately, and people would lie in a total lethargy until the unmet necessities of nature put an end to their miserable existence. It is true that so fatal an outcome is very little to be feared. Nature is always too strong for principle. And though a Pyrrhonian may throw himself and others into a momentary amazement by his profound reasoning, the first and most trivial event in life will put all his doubts to flight and leave him exactly like the philosophers of every other sect, in every point of action and speculation — or like people who never troubled themselves with philosophy at all. When he wakes from his dream he will be the first to join in the laugh against himself, and to admit that all his objections are mere amusement, and can show nothing except the whimsical condition of mankind, who must act and reason and believe, even though they cannot by their most diligent enquiry satisfy themselves about the foundation of these operations, or remove the objections that may be raised against them.
There is, however, a more mitigated scepticism, an academic philosophy, which may be both lasting and useful, and which may partly result from this Pyrrhonism, this excessive scepticism, once its indiscriminate doubts have been corrected to some extent by common sense and reflection. Most people are naturally inclined to be positive and dogmatic in their opinions; and while they see things from one side only and have no idea of any counterbalancing argument, they throw themselves headlong into whatever principles they are inclined to, with no patience for anyone who thinks otherwise. To hesitate or weigh things up perplexes their understanding, checks their passion and suspends their action. So they are impatient to escape a state they find so uncomfortable, and think they can never get far enough away from it by the violence of their assertions and the obstinacy of their belief. But if such dogmatic reasoners could be made aware of the strange infirmities of human understanding, even at its best and most careful, the reflection would naturally inspire more modesty and reserve, and would reduce their high opinion of themselves and their prejudice against their opponents. The unlearned may reflect on the disposition of the learned, who with all the advantages of study are commonly still diffident in their conclusions; and if any of the learned are inclined by temperament to haughtiness, a small dose of Pyrrhonism might reduce their pride, by showing them that the few advantages they have gained over their fellows are trifling compared with the universal perplexity inherent in human nature. In general there is a degree of doubt, caution and modesty which ought always to accompany a sound reasoner in every kind of enquiry and decision.
Another kind of mitigated scepticism which may be of benefit to mankind, and which may follow naturally from Pyrrhonian doubts, is the limiting of our enquiries to the subjects best suited to the narrow capacity of human understanding. Human imagination is naturally sublime, delighted with whatever is remote and extraordinary, and running unchecked into the most distant parts of space and time to escape the objects custom has made too familiar. Sound Judgement does the opposite: it avoids all distant and lofty enquiries and confines itself to ordinary life and to the subjects of daily practice and experience, leaving the more sublime topics to the ornaments of poets and orators, or to the arts of priests and politicians. Nothing can help bring us to so wholesome a resolution more than being thoroughly convinced, once, of the force of Pyrrhonian doubt, and of the impossibility of anything but the strong power of natural instinct freeing us from it. Those with a bent for philosophy will still carry on their researches, reflecting that besides the immediate pleasure of the occupation, philosophical conclusions are nothing but the reflections of ordinary life, made methodical and corrected. But they will never be tempted to go beyond ordinary life, so long as they keep in mind the imperfection of the faculties they are using, their narrow reach and their inexact operation. While we cannot give a satisfactory reason why we believe, after a thousand trials, that a stone will fall or fire burn, how can we ever satisfy ourselves about any conclusion we may form concerning the origin of worlds, and the state of nature from and to eternity?
This narrow limiting of our enquiries is in every respect so reasonable that the slightest examination of the natural powers of the human mind, compared with their objects, is enough to recommend it to us. We shall then find what the proper subjects of science and enquiry are.
It seems to me that the only objects of the abstract sciences, the only objects of demonstration, are quantity and number, and that every attempt to extend this more perfect kind of knowledge beyond those bounds is mere sophistry and illusion. Since the component parts of quantity and number are entirely similar to one another, their relations become intricate and involved, and nothing could be more curious or more useful than tracing their equality or inequality through their different appearances by a variety of means. But since all other ideas are clearly distinct from one another, the closest scrutiny can never take us further than observing that difference and pronouncing, by an obvious reflection, that one thing is not another. Or if there is any difficulty in such judgements, it comes entirely from the undetermined meaning of words, and is corrected by better definitions. That the square of the hypotenuse is equal to the squares of the other two sides cannot be known, however exactly the terms are defined, without a train of reasoning. But to convince us of the proposition that where there is no property, there can be no injustice, we need only define the terms, and explain injustice as a violation of property. That proposition is really nothing but an imperfect definition. It is the same with all the supposedly syllogistic reasonings to be found in every other branch of learning except the sciences of quantity and number — which may safely, I think, be pronounced the only proper objects of knowledge and demonstration.
All other human enquiries concern only matter of fact and existence, and these plainly cannot be demonstrated. Whatever is may not be. No denial of a fact can involve a contradiction. The non-existence of any being whatever is as clear and distinct an idea as its existence. The proposition asserting that it is not, however false, is no less conceivable than the one asserting that it is. It is otherwise with the sciences properly so called. There, every proposition that is not true is confused and unintelligible. That the cube root of 64 is equal to half of 10 is a false proposition and can never be distinctly conceived. But that Caesar, or the angel Gabriel, or any being never existed may be a false proposition, yet is perfectly conceivable and involves no contradiction.
So the existence of any being can only be proved by arguments from its cause or its effect, and those arguments are founded entirely on experience. If we reason in advance of experience, anything may appear capable of producing anything. The fall of a pebble might, for all we know, put out the sun, or a man's wish steer the planets in their orbits. It is only experience that teaches us the nature and limits of cause and effect, and lets us infer the existence of one object from another. Such is the foundation of moral reasoning, which makes up the greater part of human knowledge and is the source of all human action.
Moral reasoning concerns either particular facts or general ones. All the deliberations of life concern the first, as do all enquiries in history, chronology, geography and astronomy.
The sciences that deal with general facts are politics, natural philosophy, medicine, chemistry and so on, where the qualities, causes and effects of a whole class of objects are investigated.
Divinity, or theology, in so far as it proves the existence of a God and the immortality of the soul, is composed partly of reasoning about particular facts and partly about general ones. It has a foundation in reason so far as it is supported by experience. But its best and firmest foundation is faith and divine revelation.
Morals and criticism are not properly objects of the understanding so much as of taste and feeling. Beauty, whether moral or natural, is felt rather than perceived. Or if we do reason about it and try to fix its standard, we are attending to a new fact — the general tastes of mankind, or something of that sort, which can be an object of reasoning and enquiry.
When we run over a library, persuaded of these principles, what havoc must we make? If we take in our hand any volume — of divinity, say, or school metaphysics — let us ask: "Does it contain any abstract reasoning concerning quantity or number?" No. "Does it contain any experimental reasoning concerning matter of fact and existence?" No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.