But there is a second problem, less precise, and by some mistakenly regarded as unimportant - I mean the problem of how best to utilize our command over the forces of nature. This includes such burning issues as democracy versus dictatorship, capitalism versus socialism, international government versus international anarchy, free speculation versus authoritarian dogma. On such issues the laboratory can give no decisive guidance. The kind of knowledge that gives most help in solving such problems is a wide survey of human life, in the past as well as in the present, and an appreciation of the sources of misery or contentment as they appear in history. It will be found that increase of skill has not, of itself, insured any increase of human happiness or wellbeing. When men first learnt to cultivate the soil, they used their knowledge to establish a cruel cult of human sacrifice. The men who first tamed the horse employed him to pillage and enslave peaceable populations. When, in the infancy of the industrial revolution, men discovered how to make cotton goods by machinery, the results were horrible: Jefferson's movement for the emancipation of slaves in America, which had been on the point of success, was killed dead; child labor in England was developed to a point of appalling cruelty; and ruthless imperialism in Africa was stimulated in the hope that black men could be induced to clothe themselves in cotton goods. In our own day a combination of scientific genius and technical skill has produced the atomic bomb, but having produced it we are all terrified, and do not know what to do with it. These instances, from widely different periods of history, show that something more than skill is required, something which may perhaps be called 'wisdom'. This is something that must be learnt, if it can be learnt, by means of other studies than those required for scientific technique. And it is something more needed now than ever before, because the rapid growth of technique has made ancient habits of thought and action more inadequate than in any earlier time.

'Philosophy' means 'love of wisdom', and philosophy in this sense is what men must acquire if the new powers invented by technicians, and handed over by them to be wielded by ordinary men and women, are not to plunge mankind into an appalling cataclysm. But the philosophy that should be a part of general education is not the same thing as the philosophy of specialists. Not only in philosophy, but in all branches of academic study, there is a distinction between what has cultural value and what is only of professional interest. Historians may debate what happened to Sennacherib's unsuccessful expedition of 698 BC, but those who are not historians need not know the difference between it and his successful expedition three years earlier. Professional Grecians may usefully discuss a disputed reading in a play of Aeschylus, but such matters are not for the man who wishes, in spite of a busy life, to acquire some knowledge of what the Greeks achieved. Similarly the men who devote their lives to philosophy must consider questions that the general educated public does right to ignore, such as the differences between the theory of universals in Aquinas and in Duns Scotus, or the characteristics that a language must have if it is to be able, without falling into nonsense, to say things about itself. Such questions belong to the technical aspects of philosophy, and their discussion cannot form part of its contribution to general culture.

Academic education should aim at giving, as a corrective of the specialization which increase of knowledge has made unavoidable, as much as time will permit of what has cultural value in such studies as history, literature and philosophy. It should be made easy for a young man who knows no Greek to acquire through translations some understanding, however inadequate, of what the Greeks accomplished. Instead of studying the Anglo-Saxon kings over and over again at school, some attempt should be made to give a conspectus of world history, bringing the problems of our own day into relation with those of Egyptian priests, Babylonian kings, and Athenian reformers, as well as with all the hopes and despairs of the intervening centuries. But it is only of philosophy, treated from a similar point of view, that I wish to write.

Philosophy has had from its earliest days two different objects which were believed to be closely interrelated. On the one hand, it aimed at a theoretical understanding of the structure of the world; on the other hand, it tried to discover and inculcate the best possible way of life. From Heraclitus to Hegel, or even to Marx, it consistently kept both ends in view; it was neither purely theoretical nor purely practical, but sought a theory of the universe upon which to base a practical ethic.

Philosophy has thus been closely related to science on the one hand, and to religion on the other. Let us consider first the relation to science. Until the eighteenth century science was included in what was commonly called 'philosophy', but since that time the word 'philosophy' has been confined, on its theoretical side, to what is more speculative and general in the topics with which science deals. It is often said that philosophy is unprogressive, but this is largely a verbal matter: as soon as a way is found of arriving at definite knowledge on some ancient question, the new knowledge is counted as belonging to 'science', and 'philosophy' is deprived of the credit. In Greek times, and down to the time of Newton, planetary theory belonged to 'philosophy', because it was uncertain and speculative, but Newton took the subject out of the realm of the free play of hypothesis, and made it one requiring a different type of skill from that which it had required when it was still open to fundamental doubts. Anaximander, in the sixth century BC, had a theory of evolution, and maintained that men are descended from fishes. This was philosophy because it was a speculation unsupported by detailed evidence, but Darwin's theory of evolution was science, because it was based on the succession of forms of life as found in fossils, and upon the distribution of animals and plants in many parts of the world. A man might say, with enough truth to justify a joke: 'Science is what we know, and philosophy is what we don't know'. But it should be added that philosophical speculation as to what we do not yet know has shown itself a valuable preliminary to exact scientific knowledge. The guesses of the Pythagoreans in astronomy, of Anaximander and Empedocles in biological evolution, and of Democritus as to the atomic constitution of matter, provided the men of science in later times with hypotheses which, but for the philosophers, might never have entered their heads. We may say that, on its theoretical side, philosophy consists, at least in part, in the framing of large general hypotheses which science is not yet in a position to test; but when it becomes possible to test the hypotheses they become, if verified, a part of science, and cease to count as 'philosophy'.

The utility of philosophy, on the theoretical side, is not confined to speculations which we may hope to see confirmed or confuted by science within a measurable time. Some men are so impressed by what science knows that they forget what it does not know; others are so much more interested in what it does not know than in what it does that they belittle its achievements. Those who think that science is everything become complacent and cocksure, and decry all interest in problems not having the circumscribed definiteness that is necessary for scientific treatment. In practical matters they tend to think that skill can take the place of wisdom, and that to kill each other by means of the latest technique is more 'progressive', and therefore better, than to keep each other alive by old-fashioned methods. On the other hand, those who pooh-pooh science revert, as a rule, to some ancient and pernicious superstition, and refuse to admit the immense increase of human happiness which scientific technique, if widely used, would make possible. Both these attitudes are to be deplored, and it is philosophy that shows the right attitude, by making clear at once the scope and the limitations of scientific knowledge.

Leaving aside, for the moment, all questions that have to do with ethics or with values, there are a number of purely theoretical questions, of perennial and passionate interest, which science is unable to answer, at any rate at present. Do we survive death in any sense, and if so, do we survive for a time or for ever? Can mind dominate matter, or does matter completely dominate mind, or has each, perhaps, a certain limited independence? Has the universe a purpose? Or is it driven by blind necessity? Or is it a mere chaos and jumble, in which the natural laws that we think we find are only a phantasy generated by our own love of order? If there is a cosmic scheme, has life more importance in it than astronomy would lead us to suppose, or is our emphasis upon life mere parochialism and self-importance? I do not know the answer to these questions, and I do not believe that anybody else does, but I think human life would be impoverished if they were forgotten, or if definite answers were accepted without adequate evidence. To keep alive the interest in such questions, and to scrutinize suggested answers, is one of the functions of philosophy.

Those who have a passion for quick returns and for an exact balance sheet of effort and reward may feel impatient of a study which cannot, in the present state of our knowledge, arrive at certainties, and which encourages what may be thought the timewasting occupation of inconclusive meditation on insoluble problems. To this view I cannot in any degree subscribe. Some kind of philosophy is a necessity to all but the most thoughtless, and in the absence of knowledge it is almost sure to be a silly philosophy. The result of this is that the human race becomes divided into rival groups of fanatics, each group firmly persuaded that its own brand of nonsense is sacred truth, while the other side's is damnable heresy. Arians and Catholics, Crusaders and Muslims, Protestants and adherents of the Pope, Communists and Fascists, have filled large parts of the last 1,600 years with futile strife, when a little philosophy would have shown both sides in all these disputes that neither had any good reason to believe itself in the right. Dogmatism is an enemy to peace, and an insuperable barrier to democracy. In the present age, at least as much as in former times, it is the greatest of the mental obstacles to human happiness.

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. If you take your children for a picnic on a doubtful day, they will demand a dogmatic answer as to whether it will be fine or wet, and be disappointed in you when you cannot be sure. The same sort of assurance is demanded, in later life, of those who undertake to lead populations into the Promised Land. 'Liquidate the capitalists and the survivors will enjoy eternal bliss.' 'Exterminate the Jews and everyone will be virtuous.' 'Kill the Croats and let the Serbs reign.' 'Kill the Serbs and let the Croats reign.' These are samples of the slogans that have won wide popular acceptance in our time. Even a modicum of philosophy would make it impossible to accept such bloodthirsty nonsense. But so long as men are not trained to withhold judgment in the absence of evidence, they will be led astray by cocksure prophets, and it is likely that their leaders will be either ignorant fanatics or dishonest charlatans. To endure uncertainty is difficult, but so are most of the other virtues. For the learning of every virtue there is an appropriate discipline, and for the learning of suspended judgment the best discipline is philosophy.

But if philosophy is to serve a positive purpose, it must not teach mere skepticism, for, while the dogmatist is harmful, the skeptic is useless. Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or of ignorance. Knowledge is not so precise a concept as is commonly thought. Instead of saying 'I know this', we ought to say 'I more or less know something more or less like this'. It is true that this proviso is hardly necessary as regards the multiplication table, but knowledge in practical affairs has not the certainty or the precision of arithmetic. Suppose I say 'democracy is a good thing': I must admit, first, that I am less sure of this than I am that two and two are four, and secondly, that 'democracy' is a somewhat vague term which I cannot define precisely. We ought to say, therefore: 'I am fairly certain that it is a good thing if a government has something of the characteristics that are common to the British and American Constitutions', or something of this sort. And one of the aims of education ought to be to make such a statement more effective from a platform than the usual type of political slogan.

For it is not enough to recognize that all our knowledge is, in a greater or less degree, uncertain and vague; it is necessary, at the same time, to learn to act upon the best hypothesis without dogmatically believing it. To revert to the picnic: even though you admit that it may rain, you start out if you think fine weather probable, but you allow for the opposite possibility by taking mackintoshes. If you were a dogmatist you would leave the mackintoshes at home. The same principles apply to more important issues. One may say broadly: all that passes for knowledge can be arranged in a hierarchy of degrees of certainty, with arithmetic and the facts of perception at the top. That two and two are four, and that I am sitting in my room writing, are statements as to which any serious doubt on my part would be pathological. I am nearly as certain that yesterday was a fine day, but not quite, because memory does sometimes play odd tricks. More distant memories are more doubtful, particularly if there is some strong emotional reason for remembering falsely, such, for instance, as made George IV remember being at the battle of Waterloo. Scientific laws may be very nearly certain, or only slightly probable, according to the state of the evidence When you act upon a hypothesis which you know to be uncertain, your action should be such as will not have very harmful results if your hypothesis is false. In the matter of the picnic, you may risk a wetting if all your party are robust, but not if one of them is so delicate as to run a risk of pneumonia Or suppose you meet a Muggletonian, you will be justified in arguing with him, because not much harm will have beer done if Mr Muggleton was in fact as great a man as his disciples suppose, but you will not be justified in burning him at the stake, because the evil of being burnt alive is more certain than any proposition of theology. Of course if the Muggletonians were so numerous and so fanatical that either you or they must be killed the question would grow more difficult, but the general principle remains, that an uncertain hypothesis cannot justify a certain evil unless an equal evil is equally certain on the opposite hypothesis.

Philosophy, we said, has both a theoretical and a practice aim. It is now time to consider the latter.

Among most of the philosophers of antiquity there was close connection between a view of the universe and a doctrine as to the best way of life. Some of them founded fraternities which had a certain resemblance to the monastic orders of later times. Socrates and Plato were shocked by the sophists because they had no religious aims. If philosophy is to play a serious part in the lives of men who are not specialists, it must not cease to advocate some way of life. In doing this it is seeking to do something of what religion has done but with certain differences. The greatest difference is the there is no appeal to authority, whether that of tradition or that of a sacred book. The second important difference is the a philosopher should not attempt to establish a Church; Auguste Comte tried, but failed, as he deserved to do. The third is that more stress should be laid on the intellectual virtues than has been customary since the decay of Hellenic civilization.

There is one important difference between the ethical teachings of ancient philosophers and those appropriate to our own day. The ancient philosophers appealed to gentlemen of leisure, who could live as seemed good to them, and could even, if they chose, found an independent City having laws that embodied the master's doctrines. The immense majority of modern educated men have no such freedom; they have to earn their living within the existing framework of society, and they cannot make important changes in their own way of life unless they can first secure important changes in political and economic organization. The consequence is that a man's ethical convictions have to be expressed more in political advocacy, and less in his private behavior, than was the case in antiquity. And a conception of a good way of life has to be a social rather than an individual conception. Even among the ancients, it was so conceived by Plato in the Republic, but many of them had a more individualistic conception of the ends of life.

With this proviso, let us see what philosophy has to say on the subject of ethics.

To begin with the intellectual virtues: The pursuit of philosophy is founded on the belief that knowledge is good, even if what is known is painful. A man imbued with the philosophic spirit, whether a professional philosopher or not, will wish his beliefs to be as true as he can make them, and will, in equal measure, love to know and hate to be in error. This principle has a wider scope than may be apparent at first sight. Our beliefs spring from a great variety of causes: what we were told in youth by parents and school-teachers, what Powerful organizations tell us in order to make us act as they wish, what either embodies or allays our fears, what ministers to our self-esteem, and so on. Any one of these causes may happen to lead us to true beliefs, but is more likely to lead us in the opposite direction. Intellectual sobriety, therefore, will lead us to scrutinize our beliefs closely, with a view to discovering which of them there is any reason to believe true. If we are wise, we shall apply solvent criticism especially to the beliefs that we find it most painful to doubt, and to those most likely to involve us in violent conflict with men who hold opposite but equally groundless beliefs. If this attitude could become common, the gain in diminishing the acerbity of disputes would be incalculable.

There is another intellectual virtue, which is that of generally or impartially. I recommend the following exercise: When, in a sentence expressing political opinion, there are words that arouse powerful but different emotions in different readers, try replacing them by symbols, A, B. C, and so on and forgetting the particular significance of the symbols. Suppose A is England, B is Germany and C is Russia. So long as you remember what the letters mean, most of the things you will believe will depend upon whether you are English, German or Russian, which is logically irrelevant. When, in elementary algebra, you do problems about A, B and C going up a mountain, you have no emotional interest in the gentlemen concerned, and you do your best to work out the solution with impersonal correctness. But if you thought that A was yourself, B your hated rival and C the schoolmaster who set the problem, your calculations would go askew, and you would be sure to find that A was first and C was last. In thinking about political problems this kind of emotional bias is bound to be present, and only care and practice can enable you to think as objectively as you do in the algebraic problem.

Thinking in abstract terms is of course not the only way to achieve ethical generally; it can be achieved as well, or perhaps even better, if you can feel generalized emotions. But to most people this is difficult. If you are hungry, you will make great exertions, if necessary, to get food; if your children are hungry, you may feel an even greater urgency. If a friend is starving, you will probably exert yourself to relieve his distress. But if you hear that some millions of Indians or Chinese are in danger of death from malnutrition, the problem is so vast and so distant that unless you have some official responsibility you probably soon forget all about it. Nevertheless, if you have the emotional capacity to feel distant evils acutely, you can achieve ethical generally through feeling. If you have not this rather rare gift, the habit of viewing practical problems abstractly as well as concretely is the best available substitute.

The inter-relation of logical and emotional generally in ethics is an interesting subject. 'Thou shalt love thy neighbor as thyself' inculcates emotional generally; 'ethical statements should not contain proper names' inculcates logical generally. The two precepts sound very different, but when they are examined it will be found that they are scarcely distinguishable in practical import. Benevolent men will prefer the traditional form; logicians may prefer the other. I hardly know which class of men is the smaller. Either form of statement, if accepted by statesmen and tolerated by the populations whom they represent, would quickly lead to the millennium. Jews and Arabs would come together and say 'Let us see how to get the greatest amount of good for both together, without inquiring too closely how it is distributed between us'. Obviously each group would get far more of what makes for happiness of both than either can at present. The same would be true of Hindus and Moslems, Chinese communists and adherents of Chiang Kai-shek, Italians and Yugoslavs, Russians and Western democrats. But alas! neither logic nor benevolence is to be expected on either side in any of these disputes.

It is not to be supposed that young men and women who are busy acquiring valuable specialized knowledge can spare a great deal of time for the study of philosophy, but even in the time that can easily be spared without injury to the learning of technical skills, philosophy can give certain things that will greatly increase the student's value as a human being and as a citizen. It can give a habit of exact and careful thought, not only in mathematics and science, but in questions of large practical import. It can give an impersonal breadth and scope to the conception of the ends of life. It can give to the individual a just measure of himself in relation to society, of man in the present to man in the past and in the future, and of the whole history of man in relation to the astronomical cosmos. By enlarging the objects of his thoughts it supplies an antidote to the anxieties and anguish of the present, and makes possible the nearest approach to serenity that is available to a sensitive mind in our tortured and uncertain world.