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.

Whatever we know without inference is mental.

Obscenity is whatever happens to shock some elderly and ignorant magistrate.

An individual may perceive a way of life, or a method of social organisation, by which more of the desires of mankind could be satisfied than under the existing method. If he perceives truly, and can persuade men to adopt his reform, he is justified. Without rebellion, mankind would stagnate, and injustice would be irremediable.

Science may set limits to knowledge, but should not set limits to imagination.

There is much pleasure to be gained from useless knowledge.

I am ashamed of belonging to the species Homo Sapiens...You & I may be thankful to have lived in happier times - you more than I, because you have no children.

It is said (I do not know with what truth) that a certain Hindu thinker believed the earth to rest upon an elephant. When asked what the elephant rested upon, he replied that it rested upon a tortoise. When asked what the tortoise rested upon, he said, "I am tired of this. Suppose we change the subject." This illustrates the unsatisfactory character of the First-Cause argument.

Most people, at a crisis, feel more loyalty to their nation than to their class.

A life without adventure is likely to be unsatisfying, but a life in which adventure is allowed to take whatever form it will is sure to be short.

The secret of happiness is to face the fact that the world is horrible, horrible, horrible.

The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself.

As a philosopher, if I were speaking to a purely philosophic audience I should say that I ought to describe myself as an Agnostic, because I do not think that there is a conclusive argument by which one prove that there is not a God. On the other hand, if I am to convey the right impression to the ordinary man in the street I think that I ought to say that I am an Atheist, because, when I say that I cannot prove that there is not a God, I ought to add equally that I cannot prove that there are not the Homeric gods.

Every man would like to be God, if it were possible; some few find it difficult to admit the impossibility.

Probably in time physiologists will be able to make nerves connecting the bodies of different people; this will have the advantage that we shall be able to feel another man's tooth aching.

Cock-sure certainty is the source of much that is worst in our present world, and it is something of which the contemplation of history ought to cure us, not only or chiefly because there were wise men in the past, but because so much that was thought wisdom turned out to be folly - which suggests that much of our own supposed wisdom is no better. I do not mean to maintain that we should lapse into a lazy scepticism. We should hold our beliefs, and hold them strongly. Nothing great is achieved without passion, but underneath the passion there should always be that large impersonal survey which sets limits to actions that our passions inspire.

The love of power is a part of human nature, but power-philosophies are, in a certain precise sense, insane. The existence of the external world, both that of matter and of other human beings, is a datum, which may be humiliating to a certain kind of pride, but can only be denied by a madman. Men who allow their love of power to give them a distorted view of the world are to be found in every asylum: one man will think he is Governor of the Bank of England, another will think he is the King, and yet another will think he is God. Highly similar delusions, if expressed by educated men in obscure language, lead to professorships in philosophy; and if expressed by emotional men in eloquent language, lead to dictatorships. Certified lunatics are shut up because of the proneness to violence when their pretensions are questioned; the uncertified variety are given control of powerful armies, and can inflict death and disaster upon all sane men within their reach.

A stupid man's report of what a clever man says is never accurate, because he unconsciously translates what he hears into something that he can understand.

For my part, while I am as convinced a Socialist as the most ardent Marxian, I do not regard Socialism as a gospel of proletarian revenge, nor even, primarily, as a means of securing economic justice. I regard it primarily as an adjustment to machine production demanded by considerations of common sense, and calculated to increase the happiness, not only of proletarians, but of all except a tiny minority of the human race.

Men tend to have the beliefs that suit their passions. Cruel men believe in a cruel God, and use their belief to excuse their cruelty. Only kindly men believe in a kindly God, and they would be kindly in any case.

People will tell us that without the consolations of religion they would be intolerably unhappy. So far as this is true, it is a coward's argument. Nobody but a coward would consciously choose to live in a fool's paradise. When a man suspects his wife of infidelity, he is not thought the better of for shutting his eyes to the evidence. And I cannot see why ignoring evidence should be contemptible in one case and admirable in the other.

We thus have a kind of see-saw: first, pure persuasion leading to the conversion of a minority; then force exerted to secure that the rest of the community shall be exposed to the right propaganda; and finally a genuine belief on the part of the great majority, which makes the use of force again unnecessary.

Too little liberty brings stagnation, and too much brings chaos.

If the Communists conquered the world, it would be very unpleasant for a while, but not forever. But if the human race is wiped out, that is the end.

To understand the actual world as it is, not as we should wish it to be, is the beginning of wisdom.

Science seems to be at war with itself.... Naive realism leads to physics, and physics, if true, shows naive realism to be false. Therefore naive realism, if true, is false; therefore it is false.

When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others. It is much more nearly certain that we are assembled here tonight than it is that this or that political party is in the right. Certainly there are degrees of certainty, and one should be very careful to emphasize that fact, because otherwise one is landed in an utter skepticism, and complete skepticism would, of course, be totally barren and completely useless.

The fundamental concept in social science is Power, in the same sense in which Energy is the fundamental concept in physics.

I should say that the universe is just there, and that is all.

Pi's face was masked, and it was understood that none could behold it and live. But piercing eyes looked out from the mask, inexorable, cold and enigmatic.

It is not altogether true that persuasion is one thing and force is another. Many forms of persuasion - even many of which everybody approves - are really a kind of force. Consider what we do to our children. We do not say to them: "Some people think the earth is round, and others think it is flat; when you grow up, you can, if you like, examine the evidence and form your own conclusion." Instead of this we say: "The earth is round." By the time our children are old enough to examine the evidence, our propaganda has closed their minds.

In the welter of conflicting fanaticisms, one of the few unifying forces is scientific truthfulness, by which I mean the habit of basing our beliefs upon observations and inferences as impersonal, and as much divested of local and temperamental bias, as is possible for human beings.

I cannot escape from the conclusion that the great ages of progress have depended upon a small number of individuals of transcendent ability. 

There is a further advantage [to hydrogen bombs]: the supply of uranium in the planet is very limited, and it might be feared that it would be used up before the human race was exterminated, but now that the practically unlimited supply of hydrogen can be utilized, there is considerable reason to hope that homo sapiens may put an end to himself, to the great advantage of such less ferocious animals as may survive. But it is time to return to less cheerful topics.

When I come to my own beliefs, I find myself quite unable to discern any purpose in the universe, and still more unable to wish to discern one.

Competition for power is of two sorts: between organizations, and between individuals for leadership within an organization.

Self-respect will keep a man from being abject when he is in the power of enemies, and will enable him to feel that he may be in the right when the world is against him.

What is new in our time is the increased power of the authorities to enforce their prejudices.

First of all: what is work? Work is of two kinds: first, altering the position of matter at or near the earth's surface relatively to other such matter; second, telling other people to do so. The first kind is unpleasant and ill paid; the second is pleasant and highly paid.

The first thing to realize, if you wish to become a philosopher, is that most people go through life with a whole world of beliefs that have no sort of rational justification, and that one man's world of beliefs is apt to be incompatible with another man's, so that they cannot both be right. People's opinions are mainly designed to make them feel comfortable; truth, for most people is a secondary consideration.

All who are not lunatics are agreed about certain things. That it is better to be alive than dead, better to be adequately fed than starved, better to be free than a slave. Many people desire those things only for themselves and their friends; they are quite content that their enemies should suffer. These people can only be refuted by science: Humankind has become so much one family that we cannot ensure our own prosperity except by ensuring that of everyone else. If you wish to be happy yourself, you must resign yourself to seeing others also happy.

Most men do not feel in themselves the competence required for leading their group to victory, and therefore seek out a captain who appears to possess the courage and sagacity necessary for the achievement of supremacy. Even in religion this impulse appears. Nietzsche accused Christianity of inculcating a slave-morality, but ultimate triumph was always the goal. "Blessed are the meek, for they shall inherit the earth."

A physicist looks for causes; that does not necessarily imply that there are causes everywhere. A man may look for gold without assuming that there is gold everywhere; if he finds gold, well and good, if he doesn't he's had bad luck. The same is true when the physicists look for causes.

What modern apologists call 'true' Christianity is something depending upon a very selective process. It ignores much that is to be found in the Gospels: for example, the parable of the sheep and the goats, and the doctrine that the wicked will suffer eternal torment in Hell fire. It picks out certain parts of the Sermon on the Mount, though even these it often rejects in practice. It leaves the doctrine of non-resistance, for example, to be practised only by non-Christians such as Gandhi. The precepts that it particularly favours are held to embody such a lofty morality that they must have had a divine origin. And yet ... these precepts were uttered by Jews before the time of Christ.