To save the world requires faith and courage: faith in reason, and courage to proclaim what reason shows to be true.

If any philosopher had been asked for a definition of infinity, he might have produced some unintelligible rigmarole, but he would certainly not have been able to give a definition that had any meaning at all.

The instinctive foundation of the intellectual life is curiosity, which is found among animals in its elementary forms. Intelligence demands an alert curiosity, but it must be of a certain kind. The sort that leads village neighbours to try to peer through curtains after dark has no very high value. The widespread interest in gossip is inspired, not by a love of knowledge but by malice: no one gossips about other people's secret virtues, but only about their secret vices. Accordingly most gossip is untrue, but care is taken not to verify it. Our neighbour's sins, like the consolations of religion, are so agreeable that we do not stop to scrutinise the evidence closely.

I believe that the abolition of private ownership of land and capital is a necessary step toward any world in which the nations are to live at peace with one another.

A fundamental economic reconstruction, bringing with it very far-reaching changes in ways of thinking and feeling, in philosophy and art and private relations, seems absolutely necessary if industrialism is to become the servant of man instead of his master. In all this, I am at one with the Bolsheviks; politically, I criticize them only when their methods seem to involve a departure from their own ideals.

Certain forms of sex which do not lead to children are at present punished by the criminal law: this is purely superstitious, since the matter is one which affects no one except the parties directly concerned... The peculiar importance attached, at present, to adultery is quite irrational... Moral rules ought not to be such as to make instinctive happiness impossible.

Those who forget good and evil and seek only to know the facts are more likely to achieve good than those who view the world through the distorting medium of their own desires.

The Chinese are a great nation, incapable of permanent suppression by foreigners. They will not consent to adopt our vices in order to acquire military strength; but they are willing to adopt our virtues in order to advance in wisdom. I think they are the only people in the world who quite genuinely believe that wisdom is more precious than rubies. That is why the West regards them as uncivilized.

The great majority of men and women, in ordinary times, pass through life without ever contemplating or criticising, as a whole, either their own conditions or those of the world at large. They find themselves born into a certain place in society, and they accept what each day brings forth, without any effort of thought beyond what the immediate present requires. Almost as instinctively as the beasts of the field, they seek the satisfaction of the needs of the moment, without much forethought, and without considering that by sufficient effort the whole conditions of their lives could be changed.

The camera is as subjective as we are.

In obedience to the feeling of reality, we shall insist that, in the analysis of propositions, nothing "unreal" is to be admitted. But, after all, if there is nothing unreal, how, it may be asked, could we admit anything unreal? The reply is that, in dealing with propositions, we are dealing in the first instance with symbols, and if we attribute significance to groups of symbols which have no significance, we shall fall into the error of admitting unrealities, in the only sense in which this is possible, namely, as objects described.

The governors of the world believe, and have always believed, that virtue can only be taught by teaching falsehood, and that any man who knew the truth would be wicked. I disbelieve this, absolutely and entirely. I believe that love of truth is the basis of all real virtue, and that virtues based upon lies can only do harm.

Thus mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.

The average man's opinions are much less foolish than they would be if he thought for himself: in science, at least, his respect for authority is on the whole beneficial.

Only in thought is man a God; in action and desire we are the slaves of circumstance.

Essentially, this war...is a great race-conflict, a conflict of Teuton and Slav, in which certain other nations, England, France and Belgium, have been led into cooperation with the Slav. ... The conflict of Germany and Russia has been produced not by this or that diplomatic incident, but by primitive passions expressing themselves in the temper of the two races.

I do not pretend to start with precise questions. I do not think you can start with anything precise. You have to achieve such precision as you can, as you go along.

Ironclads and Maxim guns must be the ultimate arbiters of metaphysical truth.

That I, a funny little gesticulating animal on two legs, should stand beneath the stars and declaim in a passion about my rights - it seems so laughable, so out of all proportion. Much better, like Archimedes, to be killed because of absorption in eternal things... There is a possibility in human minds of something mysterious as the night-wind, deep as the sea, calm as the stars, and strong as Death, a mystic contemplation, the "intellectual love of God." Those who have known it cannot believe in wars any longer, or in any kind of hot struggle. If I could give to others what has come to me in this way, I could make them too feel the futility of fighting. But I do not know how to communicate it: when I speak, they stare, applaud, or smile, but do not understand.

I should like to believe my people's religion, which was just what I could wish, but alas, it is impossible. I have really no religion, for my God, being a spirit shown merely by reason to exist, his properties utterly unknown, is no help to my life. I have not the parson's comfortable doctrine that every good action has its reward, and every sin is forgiven. My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

Mathematics takes us still further from what is human, into the region of absolute necessity, to which not only the world, but every possible world, must conform.

Both in thought and in feeling, even though time be real, to realise the unimportance of time is the gate of wisdom.

I have been merely oppressed by the weariness and tedium and vanity of things lately: nothing stirs me, nothing seems worth doing or worth having done: the only thing that I strongly feel worth while would be to murder as many people as possible so as to diminish the amount of consciousness in the world. These times have to be lived through: there is nothing to be done with them.

I don't care for the applause one gets by saying what others are thinking; I want actually to change people's thoughts. Power over people's minds is the main personal desire of my life; and this sort of power is not acquired by saying popular things.

The life of man is a long march through the night, surrounded by invisible foes, tortured by weariness and pain, towards a goal that few can hope to reach, and where none may tarry long.

Philosophy, from the earliest times, has made greater claims, and achieved fewer results, than any other branch of learning.

Philosophy seems to me on the whole a rather hopeless business.

The Austrians are a highly civilised race, half-surrounded by Slavs in a relatively backward state of culture. ... Servia, a country so barbaric that a man can secure the throne by instigating the assassination of his predecessor, is engaged constantly in fermenting the racial discontent of men of the same race who are Austrian subjects.

My desire and wish is that the things I start with should be so obvious that you wonder why I spend my time stating them. This is what I aim at because the point of philosophy is to start with something so simple as not to seem worth stating, and to end with something so paradoxical that no one will believe it.

That Man is the product of causes that had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and his beliefs, are but the outcome of accidental collocations of atoms; that no fire, no heroism, no intensity of thought and feeling, can preserve individual life beyond the grave; that all the labors of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and that the whole temple of Man's achievement must inevitably be buried beneath the debris of a universe in ruins - all these things, if not quite beyond dispute, are yet so nearly certain that no philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul's habitation henceforth be safely built.

What a queer work the Bible is. ...Some texts are very funny. Deut. XXIV, 5: "When a man hath taken a new wife, he shall not go out to war, neither shall he be charged with any business: but he shall be free at home one year, and shall cheer up his wife which he hath taken." I should never have guessed "cheer up" was a Biblical expression. Here is another really inspiring text: "Cursed be he that lieth with his mother-in-law. And all the people shall say, Amen." St Paul on marriage: "I say therefore to the unmarried and widows, It is good for them if they abide even as I. But if they cannot contain, let them marry: for it is better to marry than to burn." This has remained the doctrine of the Church to this day. It is clear that the Divine purpose in the text "it is better to marry than to burn" is to make us all feel how very dreadful the torments of Hell must be.

I am looking forward very much to getting back to Cambridge, and being able to say what I think and not to mean what I say: two things which at home are impossible. Cambridge is one of the few places where one can talk unlimited nonsense and generalities without anyone pulling one up or confronting one with them when one says just the opposite the next day.

I like mathematics because it is not human and has nothing particular to do with this planet or with the whole accidental universe - because, like Spinoza's God, it won't love us in return.

Men fear thought as they fear nothing else on earth - more than ruin, more even than death. Thought is subversive and revolutionary, destructive and terrible; thought is merciless to privilege, established institutions, and comfortable habits; thought is anarchic and lawless, indifferent to authority, careless of the well-tried wisdom of the ages. Thought looks into the pit of hell and is not afraid. It sees man, a feeble speck, surrounded by unfathomable depths of silence; yet it bears itself proudly, as unmoved as if it were lord of the universe. Thought is great and swift and free, the light of the world, and the chief glory of man.

The past alone is truly real: the present is but a painful, struggling birth into the immutable being of what is no longer. Only the dead exist fully. The lives of the living are fragmentary, doubtful, and subject to change; but the lives of the dead are complete, free from the sway of Time, the all but omnipotent lord of the world. Their failures and successes, their hopes and fears, their joys and pains, have become eternal-our efforts cannot now abate one jot of them. Sorrows long buried in the grave, tragedies of which only a fading memory remains, loves immortalized by Death's hallowing touch these have a power, a magic, an untroubled calm, to which no present can attain. ...On the banks of the river of Time, the sad procession of human generations is marching slowly to the grave; in the quiet country of the Past, the march is ended, the tired wanderers rest, and the weeping is hushed.

I don't like the spirit of socialism - I think freedom is the basis of everything.

Brief and powerless is Man's life; on him and all his race the slow, sure doom falls pitiless and dark.

The conception of the necessary unit of all that is resolves itself into the poverty of the imagination, and a freer logic emancipates us from the straitwaistcoated benevolent institution which idealism palms off as the totality of being.

Pure Mathematics is the class of all propositions of the form "p implies q," where p and q are propositions containing one or more variables, the same in the two propositions, and neither p nor q contains any constants except logical constants. And logical constants are all notions definable in terms of the following: Implication, the relation of a term to a class of which it is a member, the notion of such that, the notion of relation, and such further notions as may be involved in the general notion of propositions of the above form. In addition to these, mathematics uses a notion which is not a constituent of the propositions which it considers, namely the notion of truth.

It must not be supposed that this conflict is, on the part of the Teuton, aggressive in substance, whatever it may be in form. In substance it is defensive, the attempt to preserve Central Europe for a type of civilisation indubitably higher and of more value to mankind than that of any Slav State. The existence of the Russian menace on the Eastern border is, quite legitimately, a nightmare to Germany.

The reason that I call my doctrine logical atomism is because the atoms that I wish to arrive at as the sort of last residue in analysis are logical atoms and not physical atoms. Some of them will be what I call "particulars" - such things as little patches of color or sounds, momentary things - and some of them will be predicates or relations and so on.

In spite of Death, the mark and seal of the parental control, Man is yet free, during his brief years, to examine, to criticise, to know, and in imagination to create. To him alone, in the world with which he is acquainted, this freedom belongs; and in this lies his superiority to the resistless forces that control his outward life.

In the visible world, the Milky Way is a tiny fragment; within this fragment, the solar system is an infinitesimal speck, and of this speck our planet is a microscopic dot. On this dot, tiny lumps of impure carbon and water, of complicated structure, with somewhat unusual physical and chemical properties, crawl about for a few years, until they are dissolved again into the elements of which they are compounded. They divide their time between labour designed to postpone the moment of dissolution for themselves and frantic struggles to hasten it for others of their kind.

Thee will find out in time that I have a great love of professing vile sentiments, I don't know why, unless it springs from long efforts to avoid priggery.

Life seems to me essentially passion, conflict, rage... It is only intellect that keeps me sane; perhaps this makes me overvalue intellect against feeling.

Political ideals must be based upon ideals for the individual life. The aim of politics should be to make the lives of individuals as good as possible.

A logical theory may be tested by its capacity for dealing with puzzles, and it is a wholesome plan, in thinking about logic, to stock the mind with as many puzzles as possible, since these serve much the same purpose as is served by experiments in physical science.

One must look into hell before one has any right to speak of heaven.

To those who inquire as to the purpose of mathematics, the usual answer will be that it facilitates the making of machines, the travelling from place to place, and the victory over foreign nations, whether in war or commerce. ... The reasoning faculty itself is generally conceived, by those who urge its cultivation, as merely a means for the avoidance of pitfalls and a help in the discovery of rules for the guidance of practical life.

The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is.