I wish to propose a doctrine which may, I fear, appear wildly paradoxical and subversive. The doctrine in question is this: that it is undesirable to believe a proposition when there is no ground whatever for supposing it true. I must, of course, admit that if such an opinion became common it would completely transform our social life and our political system; since both are at present faultless, this must weigh against it. I am also aware (what is more serious) that it would tend to diminish the incomes of clairvoyants, bookmakers, bishops, and others who live on the irrational hopes of those who have done nothing to deserve good fortune here or hereafter. In spite of these grave arguments, I maintain that a case can be made out of my paradox, and I shall try to set it forth.

First of all, I wish to guard myself against being thought to take up an extreme position. I am a British Whig, with a British love of compromise and moderation. A story is told of Pyrrho, the founder of Pyrrhonism (which was the old name for scepticism). He maintained that we never know enough to be sure that one course of action is wiser than another. In his youth, when he was taking his constitutional one afternoon, he saw his teacher in philosophy (from whom he had imbibed his principles) with his head stuck in a ditch, unable to get out. After contemplating him for some time, he walked on, maintaining that there was not sufficient ground for thinking he would do any good by pulling the man out. Others, less sceptical, effected a rescue, and blamed Pyrrho for his heartlessness. But his teacher, true to his principles, praised him for his consistency. Now I do not advocate such heroic scepticism as that. I am prepared to admit the ordinary beliefs of common sense, in practice if not in theory. I am prepared to admit any well-established result of science, not as certainly true, but as sufficiently probable to afford a basis for rational action. If it is announced that there is to be an eclipse of the moon on such-and-such a date, I think it worth while to look and see whether it is taking place. Pyrrho would have thought otherwise. On this ground, I feel justified in claiming that I advocate a middle position.

There are matters about which those who have investigated them are agreed; the dates of eclipses may serve as an illustration. There are other matters about which experts are not agreed. Even when the experts all agree, they may well be mistaken. Einstein's view as to the magnitude of the deflection of light by gravitation would have been rejected by all experts not many years ago, yet it proved to be right. Nevertheless the opinion of experts, when it is unanimous, must be accepted by non-experts as more likely to be right than the opposite opinion. The scepticism that I advocate amounts only to this: (1) that when the experts are agreed, the opposite opinion cannot be held to be certain; (2) that when they are not agreed, no opinion can be regarded as certain by a non-expert; and (3) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment.

These propositions may seem mild, yet, if accepted, they would absolutely revolutionize human life.

The opinions for which people are willing to fight and persecute all belong to one of the three classes which this scepticism condemns. When there are rational grounds for an opinion, people are content to set them forth and wait for them to operate. In such cases, people do not hold their opinions with passion; they hold them calmly, and set forth their reasons quietly. The opinions that are held with passion are always those for which no good ground exists; indeed the passion is the measure of the holder's lack of rational conviction. Opinions in politics and religion are almost always held passionately. Except in China, a man is thought a poor creature unless he has strong opinions on such matters; people hate sceptics far more than they hate the passionate advocates of opinions hostile to their own. It is thought that the claims of practical life demand opinions on such questions, and that, if we became more rational, social existence would be impossible. I believe the opposite of this, and will try to make it clear why I have this belief.

Take the question of unemployment in the years after 1920. One party held that it was due to the wickedness of trade unions, another that it was due to the confusion on the Continent. A third party, while admitting that these causes played a part, attributed most of the trouble to the policy of the Bank of England in trying to increase the value of the pound sterling. This third party, I am given to understand, contained most of the experts, but no one else. Politicians do not find any attractions in a view which does not lend itself to party declamation, and ordinary mortals prefer views which attribute misfortune to the machinations of their enemies. Consequently people fight for and against quite irrelevant measures, while the few who have a rational opinion are not listened to because they do not minister to any one's passions. To produce converts, it would have been necessary to persuade people that the Bank of England is wicked. To convert Labour, it would have been necessary to show that directors of the Bank of England are hostile to trade unionism; to convert the Bishop of London, it would have been necessary to show that they are "immoral." It would be thought to follow that their views currency are mistaken.

Let us take another illustration. It is often said that socialism is contrary to human nature, and this assertion is denied by socialists with the same heat with which it is made by their opponents. The late Dr. Rivers, whose death cannot be sufficiently deplored, discussed this question in a lecture at University College, published in his posthumous book on Psychology and Politics. This is the only discussion of this topic known to me that can lay claim to be scientific. It sets forth certain anthropological data which show that socialism is not contrary to human nature in Melanesia; it then points out that we do not know whether human nature is the same in Melanesia as in Europe; and it concludes that the only way of finding out whether socialism is contrary to European human nature is to try it. It is interesting that on the basis of this conclusion he was willing to become a Labour candidate. But he would certainly not have added to the heat and passion in which political controversies are usually enveloped.

I will now venture on a topic which people find even more difficulty in treating dispassionately, namely marriage customs. The bulk of the population of every country is persuaded that all marriage customs other than its own are immoral, and that those who combat this view do so only in order to justify their awn loose lives. In India, the remarriage of widows is traditionally regarded as a thing too horrible to contemplate. In Catholic countries divorce is thought very wicked, but some failure of conjugal fidelity is tolerated, at least in men. In America divorce is easy, but extra-conjugal relations are condemned with the utmost severity. Mohammedans believe in polygamy, which we think degrading. All these differing opinions are held with extreme vehemence, and very cruel persecutions are inflicted upon those who contravene them. Yet no one in any of the various countries makes the slightest attempt to show that the custom of his own country contributes more to human happiness than the custom of others.

When we open any scientific treatise on the subject, such as (for example) Westermarck's History of Human Marriage, we find an atmosphere extraordinarily different from that of popular prejudice. We find that every kind of custom has existed, many of them such as we should have supposed repugnant to human nature. We think we can understand polygamy, as a custom forced upon women by male oppressors. But what are we to say of the Tibetan custom, according to which one woman has several husbands? Yet travellers in Tibet assure us that family life there is at least as harmonious as in Europe. A little of such reading must soon reduce any candid person to complete scepticism, since there seem to be no data enabling us to say that one marriage custom is better or worse than another. Almost all involve cruelty and intolerance towards offenders against the local code, but otherwise they have nothing in common. It seems that sin is geographical. From this conclusion, it is only a small step to the further conclusion that the notion of "sin" is illusory, and that the cruelty habitually practiced in punishing it is unnecessary. It is just this conclusion which is so unwelcome to many minds, since the infliction of cruelty with a good conscience is a delight to moralists. That is why they invented Hell.

Nationalism is of course an extreme example of fervent belief concerning doubtful matters. I think it may be safely said that any scientific historian, writing now a history of the Great War, is bound to make statements which, if made during the war, would have exposed him to imprisonment in every one of the belligerent countries on both sides. Again, with the exception of China, there is no country where people tolerate the truth about themselves; at ordinary times the truth is only thought ill-mannered, but in war-time it is thought criminal. Opposing systems of violent belief are built up, the falsehood of which is evident from the fact that they are believed only by those who share the same national bias. But the application of reason to these systems of belief is thought as wicked as the application of reason to religious dogmas was formerly thought. When people are challenged as to why scepticism in such matters should be wicked, the only answer is that myths help to win wars, so that a rational nation would be killed rather than kill. The view that there is something shameful in saving one's skin by wholesale slander of foreigners is one which, so far as I know, has hitherto found no supporters among professional moralists outside the ranks of Quakers. If it is suggested that a rational nation would find ways of keeping out of wars altogether, the answer is usually more abuse.

What would be the effect of a spread of rational scepticism? Human events spring from passions, which generate systems of attendant myths. Psychoanalysts have studied the individual manifestations of this process in lunatics, certified and uncertified. A man who has suffered some humiliation invents a theory that he is King of England, and develops all kinds of ingenious explanations of the fact that he is not treated with that respect which his exalted position demands. In this case, his delusion is one with which his neighbours do not sympathize, so they lock him up. But if, instead of asserting only his own greatness, he asserts the greatness of his nation or his class or his creed, he wins hosts of adherents, and becomes a political or religious leader, even if, to the impartial outsider, his views seem just as absurd as those found in asylums. In this way a collective insanity grows up, which follows laws very similar to those of individual insanity. Every one knows that it is dangerous to depute with a lunatic who thinks he is King of England; but as he is isolated, he can be overpowered. When a whole nation shares a delusion, its anger is of the same kind as that of an individual lunatic if its pretensions are disputed, but nothing short of war can compel it to submit to reason.

The part played by intellectual factors in human behaviour is a matter as to which there is much disagreement among psychologists. There are two quite distinct questions: (1) how far are beliefs operative as causes of actions? (2) how far are beliefs derived from logically adequate evidence, or capable of being so derived? On both questions, psychologists are agreed in giving a much smaller place to the intellectual factors than the plain man would give, but within this general agreement there is room for considerable differences of degree. Let us take the two questions in succession.

(1) How far are beliefs operative as causes of action? Let us not discuss the question theoretically, but let us take an ordinary day of an ordinary man's life. He begins by getting up in the morning, probably from force of habit, without the intervention of any belief. He eats his breakfast, catches his train, reads his newspaper, and goes to his office, all from force of habit. There was a time in the past when he formed these habits, and in the choice of the office, at least, belief played a part. He probably believed, at the time, that the job offered him there was as good as he was likely to get. In most men, belief plays a part in the original choice of a career, and therefore, derivatively, in all that is entailed by this choice.

At the office, if he is an underling, he may continue to act merely from habit, without active volition, and without the explicit intervention of belief. It might be thought that, if he adds up the columns of figures, he believes the arithmetical rules which he employs. But that would be an error; these rules are mere habits of his body, like those of a tennis player. They were acquired in youth, not from an intellectual belief that they corresponded to the truth, but to please the schoolmaster, just as a dog learns to sit on its hind legs and beg for food. I do not say that all education is of this sort, but certainly most learning of the three R's is.

If, however, our friend is a partner or director, he may be called upon during his day to make difficult decisions of policy. In these decisions it is probable that belief will play a part. He believes that some things will go up and others will go down, that so-and-so is a sound man, and such-and-such on the verge of bankruptcy. On these beliefs he acts. It is just because he is called upon to act on beliefs rather than mere habits that he is considered such a much greater man than a mere clerk, and is able to get so much more money -- provided his beliefs are true.

In his home-life there will be much the same proportion of occasions when belief is a cause of action. At ordinary times, his behaviour to his wife and children will be governed by habit, or by instinct modified by habit. On great occasions -- when he proposes marriage, when he decides what school to send his son to, or when he finds reason to suspect his wife of unfaithfulness -- he cannot be guided wholly by habit. In proposing marriage, he may be guided more by instinct, or he may be influenced by the belief that the lady is rich. If he is guided by instinct, he no doubt believes that the lady possesses every virtue, and this may seem to him to be a cause of his action, but in fact it is merely another effect of the instinct which alone suffices to account for his action. In choosing a school for his son, he probably proceeds in much the same way as in making difficult business decisions; here belief usually plays an important part. If evidence comes into his possession showing that his wife has been unfaithful, his behaviour is likely to be purely instinctive, but the instinct is set in operation by a belief, which is the first cause of everything that follows.

Thus, although beliefs are not directly responsible for more than a small part of our actions, the actions for which they are responsible are among the most important, and largely determine the general structure of our lives. In particular, our religious and political actions are associated with beliefs.

(2) I come now to our second question, which is itself twofold: (a) how far are beliefs in fact based upon evidence? (b) how far is it possible or desirable that they should be?

(a) The extent to which beliefs are based upon evidence is very much less than believers suppose. Take the kind of action which is most nearly rational: the investment of money by a rich City man. You will often find that his view (say) on the question whether the French franc will go up or down depends upon his political sympathies, and yet is so strongly held that he is prepared to risk money on it. In bankruptcies it often appears that some sentimental factor was the original cause of ruin. Political opinions are hardly ever based upon evidence, except in the case of civil servants, who are forbidden to give utterance to them. There are of course exceptions. In the tariff reform controversy which began several years ago, most manufacturers supported the side that would increase their own incomes, showing that their opinions were really based on evidence, however little their utterances would have led one to suppose so. We have here a complication. Freudians have accustomed us to "rationalizing," i.e. the process of inventing what seem to ourselves rational grounds for a decision or opinion that is in fact quite irrational. But there is, especially in English-speaking countries, a converse process which may be called "irrationalizing." A shrewd man will sum up, more or less subconsciously, the pros and cons of a question from a selfish point of view. (Unselfish considerations seldom weigh subconsciously except where one's children are concerned.) Having come to a sound egoistic decision by the help of the unconscious, a man proceeds to invent, or adopt from others, a set of high-sounding phrases showing how he is pursuing the public good at immense personal sacrifice. Anybody who believes that these phrases give his real reasons must suppose him quite incapable of judging evidence, since the supposed public good is not going to result from his action. In this case a man appears less rational than he is; what is still more curious, the irrational part of him is conscious and the rational part unconscious. It is this trait in our characters that has made the English and Americans so successful.

Shrewdness, when it is genuine, belong, more to the unconscious than to the conscious part of our nature. It is, I suppose, the main quality required for success in business. From a moral point of view, it is a humble quality, since it is always selfish; yet it suffices to keep men from the worst crimes. If the Germans had had it, they would not have adopted the unlimited submarine campaign. If the French had had it, they would not have behaved as they did in the Ruhr. If Napoleon had had it, he would not have gone to war again after the Treaty of Amiens. It may be laid down as a general rule to which there are few exceptions that, when people are mistaken as to what is to their own interest, the course that they believe to be wise is more harmful to others than the course that really is wise. Therefore anything that makes people better judges of their own interest does good. There are innumerable examples of men making fortunes because, on moral grounds, they did something which they believed to be contrary to their own interests. For instance, among early Quakers there were a number of shopkeepers who adopted the practice of asking no more for their goods than they were willing to accept, instead of bargaining with each customer, as everybody else did. They adopted this practice because they held it to be a lie to ask more than they would take. But the convenience to customers was so great that everybody came to their shops, and they grew rich. (I forget where I read this, but if my memory serves me it was in some reliable source.) The same policy might have been adopted from shrewdness, but in fact no one was sufficiently shrewd. Our unconscious is more malevolent than it pays us to be; therefore the people who do most completely what is in fact to their interest are those who deliberately, on moral grounds, do what they believe to be against their interest. Next to them come the people who try to think out rationally and consciously what is to their own interest, eliminating as far as possible the influence of passion. Third come the people who have instinctive shrewdness. Last of all come the people whose malevolence overbalances their shrewdness, making them pursue the ruin of others in ways that lead to their own ruin. This last class embraces 90 per cent. of the population of Europe.

I may seem to have digressed somewhat from my topic, but it was necessary to disentangle unconscious reason, which is called shrewdness, from the conscious variety. The ordinary methods of education have practically no effect upon the unconscious, so that shrewdness cannot be taught by our present technique. Morality, also, except where it consists of mere habit, seems incapable of being taught by present methods; at any rate I have never noticed any beneficent effect upon those who are exposed to frequent exhortations. Therefore on our present lines any deliberate improvement must be brought about by intellectual means. We do not know how to teach people to be shrewd or virtuous, but we do know, within limits, how to teach them to be rational: it is only necessary to reverse the practice of education authorities in every particular. We may hereafter learn to create virtue by manipulating the ductless glands and stimulating or restraining their secretions. But for the present it is easier to create rationality than virtue -- meaning by "rationality" a scientific habit of mind in forecasting the effects of our actions.

(b) This brings me to the question: How far could or should men's actions be rational? Let us take "should" first. There are very definite limits, to my mind, within which rationality should be confined; some of the most important departments of life are ruined by the invasion of reason. Leibniz in his old age told a correspondent that he had only once asked a lady to marry him, and that was when he was fifty. "Fortunately," he added, "the lady asked time to consider. This gave me also time to consider, and I withdrew the offer." Doubtless his conduct was very rational, but I cannot say that I admire it

Shakespeare puts "the lunatic, the lover, and the poet" together, as being "of imagination all compact." The problem is to keep the lover and the poet, without the lunatic. I will give an illustration. In 1919 I saw The Trojan Women acted at the Old Vic. There is an unbearably pathetic scene where Astyanax is put to death by the Greeks for fear he should grow up into a second Hector. There was hardly a dry eye in the theatre, and the audience found the cruelty of the Greeks in the play hardly credible. Yet those very people who wept were, at that very moment, practicing that very cruelty on a scale which the imagination of Euripides could have never contemplated. They had lately voted (most of them) for a Government which prolonged the blockade of Germany after the armistice, and imposed the blockade of Russia. It was known that these blockades caused the death of immense numbers of children, but it was felt desirable to diminish the population of enemy countries: the children, like Astyanax, might grow up to emulate their fathers. Euripides the poet awakened the lover in the imagination of the audience; but lover and poet were forgotten at the door of the theatre, and the lunatic (in the shape of the homicidal maniac) controlled the political actions of these men and women who thought themselves kind and virtuous.

Is it possible to preserve the lover and the poet without preserving the lunatic? In each of us, all three exist in varying degrees. Are they so bound up together that when the one is brought under control the others perish? I do not believe it. I believe there is in each of us a certain energy which must find vent in art, in passionate love, or in passionate hate, according to circumstances. Respectability, regularity, and routine -- the whole cast-iron discipline of a modern industrial society -- have atrophied the artistic impulse, and imprisoned love so that it can no longer be generous and free and creative, but must be either stuffy or furtive. Control has been applied to the very things which should be free, while envy, cruelty, and hate sprawl at large with the blessing of nearly the whole bench of Bishops. Our instinctive apparatus consists of two parts -- the one tending to further our own life and that of our descendants, the other tending to thwart the lives of supposed rivals. The first includes the joy of life, and love, and art, which is psychologically an offshoot of love. The second includes competition, patriotism, and war. Conventional morality does everything to suppress the first and encourage the second. True morality would do the exact opposite. Our dealings with those whom we love may be safely left to instinct; it is our dealings with those whom we hate that ought to be brought under the dominion of reason. In the modern world, those whom we effectively hate are distant groups, especially foreign nations. We conceive them abstractly, and deceive ourselves into the belief that acts which are really embodiments of hatred are done from love of justice or some such lofty motive. Only a large measure of scepticism can tear away the veils which hide this truth from us. Having achieved that, we could begin to build a new morality, not based on envy and restriction, but on the wish for a full life and the realization that other human beings are a help and not a hindrance when once the madness of envy has been cured. This is not a Utopian hope; it was partially realized in Elizabethan England. It could be realized tomorrow if men would learn to pursue their own happiness rather than the misery of others. This is no impossibly austere morality, yet its adoption would turn our earth into a paradise.