The best authorities are unanimous in saying that a war with H-bombs might possibly put an end to the human race. It is feared that if many H-bombs are used there will be universal death, sudden only for a minority, but for the majority a slow torture of disease and disintegration. Many warnings have been uttered by eminent men of science and by authorities in military strategy. None of them will say that the worst results are certain. What they do say is that these results are possible, and no one can be sure that they will not be realized. We have not yet found that the views of experts on this question depend in any degree upon their politics or prejudices. They depend only, so far as our researches have revealed, upon the extent of the particular expert's knowledge. We have found that the men who know most are the most gloomy.

The good life, as I conceive it, is a happy life. I do not mean that if you are good you will be happy; I mean that if you are happy you will be good.

As soon as it is held that any belief, no matter what, is important for some other reason than that it is true, a whole host of evils is ready to spring up. Discouragement of inquiry, ... is the first of these, but others are pretty sure to follow. Positions of authority will be open to the orthodox. Historical records must be falsified if they throw doubt on received opinion. Sooner or later unorthodoxy will come to be considered a crime to be dealt with by the stake, the purge, or the concentration camp. I can respect the men who argue that religion is true and therefore ought to be believed, but I can only feel profound moral reprobation for those who say that religion ought to be believed because it is useful, and that to ask whether it is true is a waste of time.

Man is a rational animal - so at least I have been told. Throughout a long life, I have looked diligently for evidence in favor of this statement, but so far I have not had the good fortune to come across it, though I have searched in many countries spread over three continents. Often paraphrased as "It has been said that man is a rational animal. All my life I have been searching for evidence which could support this."

We may define "faith" as a firm belief in something for which there is no evidence. Where there is evidence, no one speaks of "faith". We do not speak of faith that two and two are four or that the earth is round. We only speak of faith when we wish to substitute emotion for evidence. The substitution of emotion for evidence is apt to lead to strife, since different groups substitute different emotions.

This idea of weapons of mass extermination is utterly horrible and is something which no one with one spark of humanity can tolerate. I will not pretend to obey a government which is organising a mass massacre of mankind.

The world at present is obsessed by the conflict of rival ideologies, and one of the apparent causes of conflict is the desire for the victory of our own ideology and the defeat of the other. I do not think that the fundamental motive here has much to do with ideologies. I think the ideologies are merely a way of grouping people, and that the passions involved are merely those which always arise between rival groups. Ideologies, in fact, are one of the methods by which herds are created, and the psychology is much the same however the herd may have been generated.

I wanted certainty in the kind of way in which people want religious faith. I thought that certainty is more likely to be found in mathematics than elsewhere. But I discovered that many mathematical demonstrations, which my teachers expected me to accept, were full of fallacies, and that, if certainty were indeed discoverable in mathematics, it would be in a new field of mathematics, with more solid foundations than those that had hitherto been thought secure. But as the work proceeded, I was continually reminded of the fable about the elephant and the tortoise. having constructed an elephant upon which the mathematical world could rest, I found the elephant tottering, and proceeded to construct a tortoise to keep the elephant from falling. But the tortoise was no more secure than the elephant, and after some twenty years of very arduous toil, I came to the conclusion that there was nothing more that I could do in the way of making mathematical knowledge indubitable.

Fanaticism is the danger of the world, and always has been, and has done untold harm. I might almost say that I was fanatical against fanaticism.

Science, ever since the time of the Arabs, has had two functions: (1) to enable us to know things, and (2) to enable us to do things.

If you're certain, you're certainly wrong, because nothing deserves certainty.

Power, like vanity, is insatiable. Nothing short of omnipotence could satisfy it completely. And as it is especially the vice of energetic men, the causal efficacy of love of power is out of all proportion to its frequency. It is, indeed, by far the strongest motive in the lives of important men. Love of power is greatly increased by the experience of power, and this applies to petty power as well as to that of potentates.

Most of us are not neutral in feeling, but, as human beings, we have to remember that, if the issues between East and West are to be decided in any manner that can give any possible satisfaction to anybody, whether Communist or anti-Communist, whether Asian or European or American, whether White or Black, then these issues must not be decided by war. We should wish this to be understood, both in the East and in the West.

I observe that a very large portion of the human race does not believe in God and suffers no visible punishment in consequence. And if there were a God, I think it very unlikely that he would have such an uneasy vanity as to be offended by those who doubt his existence.

All sources of energy upon which industry depends are wasted when they are employed; and industry is expending them at a continually increasing rate. Already coal has been largely replaced by oil, and oil is being used up so fast that East and West alike conceive it necessary to their own prosperity to destroy the industry of the other. And what is true of oil is equally true of other natural resources. Every day, many square miles of forest are turned into newspaper, but there is no known process by which newspaper can be turned into forest. You will say that this need not worry us, since newspapers will be replaced by radio, but radio requires electricity, electricity requires power, and power depends upon raw materials.

There was once a millionaire who bought an infinite number of pairs of shoes and, whenever he bought a pair of shoes, he also bought a pair of socks. We can make a selection choosing one out of each pair of shoes, because we can choose always the right shoe or always the left shoe. Thus, so far as the shoes are concerned, selections exist. But, as regards the socks, where there is no distinction of right and left, we cannot use this rule of selection.

Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.

There is something feeble and a little contemptible about a man who cannot face the perils of life without the help of comfortable myths. Almost inevitably some part of him is aware that they are myths and that he believes them only because they are comforting. But he dare not face this thought! Moreover, since he is aware, however dimly, that his opinions are not rational, he becomes furious when they are disputed.

I resolved from the beginning of my quest that I would not be misled by sentiment and desire into beliefs for which there was no good evidence.

If the Russians still adhered to the Greek Orthodox religion, if they had instituted parliamentary government, and if they had a completely free press which daily vituperated us, then - provided they still had armed forces as powerful as they have now - we should still hate them if they gave us ground for thinking them hostile.

The second matter in which Mill's principles condemn existing legislation is homosexuality. If two adults voluntarily enter into such a relation, this is a matter which concerns them only, and in which, therefore, the community ought not to intervene. If it were still believed, as it once was, that the toleration of such behavior would expose the community to the fate of Sodom and Gomorrah, the community would have every right to intervene. But it does not acquire a right to intervene merely on the ground that such conduct is thought wicked. The criminal law may rightly be invoked to prevent violence or fraud inflicted upon unwilling victims, but it ought not to be invoked when whatever damage there may be is suffered only by the agents-always assuming that the agents are adults.

When I was a boy, I had a clock with a pendulum that could be lifted off. I found that the clock went very much faster without the pendulum. If the main purpose of a clock is to go, the clock was the better for losing its pendulum. True, it could no longer tell the time, but that did not matter if one could teach oneself to be indifferent to the passage of time. The linguistic philosophy which cares only about language and not about the world, is like the boy who preferred the clock without the pendulum because, although it no longer told the time, it went more easily than before and at a more exhilarating pace.

Some part of life - perhaps the most important part - must be left to the spontaneous action of individual impulse, for where all is system there will be mental and spiritual death.

I find that the whiter my hair becomes the more ready people are to believe what I say.

The pursuit of knowledge is, I think, mainly actuated by love of power. And so are all advances in scientific technique. In politics, also, a reformer may have just as strong a love of power as a despot. It would be a complete mistake to decry love of power altogether as a motive. Whether you will be led by this motive to actions which are useful, or to actions which are pernicious, depends upon the social system, and upon your capacities.

There lies before us, if we choose, continual progress in happiness, knowledge, and wisdom. Shall we, instead, choose death, because we cannot forget our quarrels? We appeal as human beings to human beings: Remember your humanity, and forget the rest. If you can do so, the way lies open to a new Paradise; if you cannot, there lies before you the risk of universal death.

I have always thought respectable people scoundrels, and I look anxiously at my face every morning for signs of my becoming a scoundrel.

It is sometimes maintained that racial mixture is biologically undesirable. There is no evidence whatever for this view. Nor is there, apparently, any reason to think that Negroes are congenitally less intelligent than white people, but as to that it will be difficult to judge until they have equal scope and equally good social conditions.

Some modern philosophers have gone so far as to say that words should never be confronted with facts but should live in a pure, autonomous world where they are compared only with other words. When you say, 'the cat is a carnivorous animal,' you do not mean that actual cats eat actual meat, but only that in zoology books the cat is classified among carnivora. These authors tell us that the attempt to confront language with fact is 'metaphysics' and is on this ground to be condemned. This is one of those views which are so absurd that only very learned men could possibly adopt them.

Neither a man nor a crowd nor a nation can be trusted to act humanely or to think sanely under the influence of a great fear.

If you think that your belief is based upon reason, you will support it by argument, rather than by persecution, and will abandon it if the argument goes against you. But if your belief is based on faith, you will realize that argument is useless, and will therefore resort to force either in the form of persecution or by stunting and distorting the minds of the young in what is called "education". This last is particularly dastardly, since it takes advantage of the defencelessness of immature minds. Unfortunately it is practiced in greater or less degree in the schools of every civilised country.

Truth is a shining goddess, always veiled, always distant, never wholly approachable, but worthy of all the devotion of which the human spirit is capable.

I do not think it can be questioned that sympathy is a genuine motive, and that some people at some times are made somewhat uncomfortable by the sufferings of some other people. It is sympathy that has produced the many humanitarian advances of the last hundred years. We are shocked when we hear stories of the ill-treatment of lunatics, and there are now quite a number of asylums in which they are not ill-treated. Prisoners in Western countries are not supposed to be tortured, and when they are, there is an outcry if the facts are discovered. We do not approve of treating orphans as they are treated in Oliver Twist.

In fact, contempt for happiness is usually contempt for other people's happiness, and is an elegant disguise for hatred of the human race.

Just as we teach children to avoid being destroyed by motor cars if they can, so we should teach them to avoid being destroyed by cruel fanatics, and to this end we should seek to produce independence of mind, somewhat sceptical and wholly scientific, and to preserve, as far as possible, the instinctive joy of life that is natural to healthy children. This is the task of a liberal education: to give a sense of the value of things other than domination, to help create wise citizens of a free community, and through the combination of citizenship with liberty in individual creativeness to enable men to give to human life that splendour which some few have shown that it can achieve.

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.

I think modern educational theorists are inclined to attach too much importance to the negative virtue of not interfering with children, and too little to the positive merit of enjoying their company.

I once received a letter from an eminent logician, Mrs. Christine Ladd Franklin, saying that she was a solipsist, and was surprised that there were no others. Coming from a logician, this surprise surprised me.

There are some simple maxims [...] which I think might be commanded to writers of expository prose. First: never use a long word if a short word will do. Second: if you want to make a statement with a great many qualifications, put some of the qualifications in separate sentences. Third: do not let the beginning of your sentence lead the reader to an expectation which is contradicted by the end.

Among human beings, the subjection of women is much more complete at a certain level of civilization than it is among savages. And the subjection is always reinforced by morality.

It is impossible to imagine a more dramatic and horrifying combination of scientific triumph with political and moral failure than has been shown to the world in the destruction of Hiroshima. From the scientific point of view, the atomic bomb embodies the results of a combination of genius and patience as remarkable as any in the history of mankind.

In the past, there was a small leisure class and a larger working class. The leisure class enjoyed advantages for which there was no basis in social justice; this necessarily made it oppressive, limited its sympathies, and caused it to invent theories by which to justify its privileges.

It is entirely clear that there is only one way in which great wars can be permanently prevented, and that is the establishment of an international government with a monopoly of serious armed force.

We need a science to save us from science.

Power may be defined as the production of intended effects.

Instinctively we divide mankind into friends and foes - friends, towards whom we have the morality of co-operation; foes, towards whom we have that of competition. But this division is constantly changing; at one moment a man hates his business competitor, at another, when both are threatened by Socialism or by an external enemy, he suddenly begins to view him as a brother. Always when we pass beyond the limits of the family it is the external enemy which supplies the cohesive force. In times of safety we can afford to hate our neighbour, but in times of danger we must love him.

Choose your parents wisely.

Ever since the war began, I have felt that I could no longer go on being a pacifist, but I have hesitated to say so, because of the responsibility involved. If I were young enough to fight myself, I should do so, but it is more difficult to urge others. Now, however, I feel that I ought to announce that I have changed my mind.

Not to be absolutely certain is, I think, one of the essential things in rationality. 

Two men who differ as to the ends of life cannot hope to agree about education.