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.

Change is one thing, progress is another.

Diet, injections, and injunctions will combine, from a very early age, to produce the sort of character and the sort of beliefs that the authorities consider desirable, and any serious criticism of the powers that be will become psychologically impossible. Even if all are miserable, all will believe themselves happy, because the government will tell them that they are so.

The state is primarily an organization for killing foreigners.

The politician may change sides so frequently as to find himself always in the majority, but most politicians have a preference for one party to the other, and subordinate their love of power to this preference.

We invite this Congress, and through it the scientists of the world and the general public, to subscribe to the following resolution: "In view of the fact that in any future world war nuclear weapons will certainly be employed, and that such weapons threaten the continued existence of mankind, we urge the governments of the world to realize, and to acknowledge publicly, that their purpose cannot be furthered by a world war, and we urge them, consequently, to find peaceful means for the settlement of all matters of dispute between them".

Thank you for your letter and for the enclosure which I return herewith. I have been wondering whether there is any means of preventing the confusion between you and me, and I half-thought that we might write a joint letter to The Times in the following terms: Sir, To prevent the continuation of confusions which frequently occur, we beg to state that neither of us is the other. Do you think this would be a good plan?

Our great democracies still tend to think that a stupid man is more likely to be honest than a clever man, and our politicians take advantage of this prejudice by pretending to be even more stupid than nature made them.

I do not think it possible to get anywhere if we start from scepticism. We must start from a broad acceptance of whatever seems to be knowledge and is not rejected for some specific reason.

All human activity is prompted by desire. There is a wholly fallacious theory advanced by some earnest moralists to the effect that it is possible to resist desire in the interests of duty and moral principle. I say this is fallacious, not because no man ever acts from a sense of duty, but because duty has no hold on him unless he desires to be dutiful. If you wish to know what men will do, you must know not only, or principally, their material circumstances, but rather the whole system of their desires with their relative strengths.

We are speaking on this occasion, not as members of this or that nation, continent, or creed, but as human beings, members of the species Man, whose continued existence is in doubt.

Perhaps the best hope for the future of mankind is that ways will be found of increasing the scope and intensity of sympathy.

The harm that is done by a religion is of two sorts, the one depending on the kind of belief which it is thought ought to be given to it, and the other upon the particular tenets believed. As regards the kind of belief: it is thought virtuous to have faith-that is to say, to have a conviction which cannot be shaken by contrary evidence. Or, if contrary evidence might induce doubt, it is held that contrary evidence must be suppressed.

The essence of the Liberal outlook lies not in what opinions are held, but in how they are held: instead of being held dogmatically, they are held tentatively, and with a consciousness that new evidence may at any moment lead to their abandonment.

If throughout your life you abstain from murder, theft, fornication, perjury, blasphemy, and disrespect toward your parents, your church, and your king, you are conventionally held to deserve moral admiration even if you have never done a single kind or generous or useful action. This very inadequate notion of virtue is an outcome of taboo morality, and has done untold harm.

You, your families, your friends and your countries are to be exterminated by the common decision of a few brutal but powerful men. To please these men, all the private affections, all the public hopes, all that has been achieved in art, and knowledge and thought and all that might be achieved hereafter is to be wiped out forever. Our ruined lifeless planet will continue for countless ages to circle aimlessly round the sun unredeemed by the joys and loves, the occasional wisdom and the power to create beauty which have given value to human life.

What is serious about excitement is that so many of its forms are destructive. It is destructive in those who cannot resist excess in alcohol or gambling. It is destructive when it takes the form of mob violence. And above all it is destructive when it leads to war. It is so deep a need that it will find harmful outlets of this kind unless innocent outlets are at hand. There are such innocent outlets at present in sport, and in politics so long as it is kept within constitutional bounds. But these are not sufficient, especially as the kind of politics that is most exciting is also the kind that does most harm. Civilized life has grown altogether too tame, and, if it is to be stable, it must provide harmless outlets for the impulses which our remote ancestors satisfied in hunting.

When I was a child the atmosphere in the house was one of puritan piety and austerity. There were family prayers at eight o'clock every morning. Although there were eight servants, food was always of Spartan simplicity, and even what there was, if it was at all nice, was considered too good for children. For instance, if there was apple tart and rice pudding, I was only allowed the rice pudding. Cold baths all the year round were insisted upon, and I had to practice the piano from seven-thirty to eight every morning although the fires were not yet lit. My grandmother never allowed herself to sit in an armchair until the evening. Alcohol and tobacco were viewed with disfavor although stern convention compelled them to serve a little wine to guests. Only virtue was prized, virtue at the expense of intellect, health, happiness, and every mundane good.

There is no need to worry about mere size. We do not necessarily respect a fat man more than a thin man. Sir Isaac Newton was very much smaller than a hippopotamus, but we do not on that account value him less.

The criminal law has, from the point of view of thwarted virtue, the merit of allowing an outlet for those impulses of aggression which cowardice, disguised as morality, restrains in their more spontaneous forms. War has the same merit. You must not kill you neighbor, whom perhaps you genuinely hate, but by a little propaganda this hate can be transferred to some foreign nation, against whom all your murderous impulses become patriotic heroism.

I must before I die, find some way to say the essential thing that is in me, that I have never said yet - a thing that is not love or hate or pity or scorn, but the very breath of life, fierce and coming from far away, bringing into human life the vastness and fearful passionless force of non-human things...

Man differs from other animals in one very important respect, and that is that he has some desires which are, so to speak, infinite, which can never be fully gratified, and which would keep him restless even in Paradise. The boa constrictor, when he has had an adequate meal, goes to sleep, and does not wake until he needs another meal. Human beings, for the most part, are not like this.

The world is full of conflicts; and, overshadowing all minor conflicts, the titanic struggle between Communism and anti-Communism. Almost everybody who is politically conscious has strong feelings about one or more of these issues; but we want you, if you can, to set aside such feelings and consider yourselves only as members of a biological species which has had a remarkable history, and whose disappearance none of us can desire. We shall try to say no single word which should appeal to one group rather than to another. All, equally, are in peril, and, if the peril is understood, there is hope that they may collectively avert it.

Politics is concerned with herds rather than with individuals, and the passions which are important in politics are, therefore, those in which the various members of a given herd can feel alike.

The conviction that it is important to believe this or that, even if a free inquiry would not support the belief, is one which is common to almost all religions and which inspires all systems of state education. The consequence is that the minds of the young are stunted and are filled with fanatical hostility both to those who have other fanaticisms, and, even more virulently, to those who object to all fanaticisms.

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.

Suppose atomic bombs had reduced the population of the world to one brother and one sister, should they let the human race die out? I do not know the answer, but I do not think it can be in the affirmative merely on the ground that incest is wicked.

We used to think that Hitler was wicked when he wanted to kill all the Jews, but what Kennedy and Macmillan and others both in the East and in the West pursue policies which will probably lead to killing not only all the Jews but all the rest of us too. They are much more wicked than Hitler and this idea of weapons of mass extermination is utterly and absolutely horrible and it is a thing which no man with one spark of humanity can tolerate and I will not pretend to obey a government which is organising the massacre of the whole of mankind. I will do anything I can to oppose such Governments in any non-violent way that seems likely to be fruitful, and I should exhort all of you to feel the same way. We cannot obey these murderers. They are wicked and abominable. They are the wickedest people that ever lived in the history of man and it is our duty to do what we can.

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.