It is clear that thought is not free if the profession of certain opinions makes it impossible to earn a living. It is clear also that thought is not free if all the arguments on one side of a controversy are perpetually presented as attractively as possible, while the arguments on the other side can only be discovered by diligent search.

Men who are unhappy, like men who sleep badly, are always proud of the fact.

There is one very serious defect to my mind in Christ's moral character, and that is that He believed in hell. I do not myself feel that any person who is really profoundly humane can believe in everlasting punishment.

Ordinary language is totally unsuited for expressing what physics really asserts, since the words of everyday life are not sufficiently abstract. Only mathematics and mathematical logic can say as little as the physicist means to say.

With our present industrial technique we can, if we choose, provide a tolerable subsistence for everybody. We could also secure that the world's population should be stationary if we were not prevented by the political influence of churches which prefer war, pestilence, and famine to contraception. The knowledge exists by which universal happiness can be secured; the chief obstacle to its utilization for that purpose is the teaching of religion. Religion prevents our children from having a rational education; religion prevents us from removing fundamental causes of war; religion prevents us from teaching the ethic of scientific co-operation in place of the old fierce doctrines of sin and punishment. It is possible that mankind is on the threshold of a golden age; but, if so, it will be necessary first to slay the dragon that guards the door, and this dragon is religion.

It is obvious that "obscenity" is not a term capable of exact legal definition; in the practice of the Courts, it means "anything that shocks the magistrate."

I am against a League war in present circumstances, because the anti-League powers are strong. The analogy is not King v. Barons, but the War of the Roses. If the League were strong enough I should favour sanctions, because the effect would suffice, or the war would be short and small. The whole question is quantitative.

Belief in eternal hell fire was an essential item of Christian belief until pretty recent times. In this country, as you know, it ceased to be an essential item because of a decision of the Privy Council, and from that decision the Archbishop of Canterbury and the Archbishop of York dissented; but in this country our religion is settled by Act of Parliament, and therefore the Privy Council was able to override Their Graces and hell was no longer necessary to a Christian. Consequently I shall not insist that a Christian must believe in hell. What is a Christian?

Marriage is for women the commonest mode of livelihood, and the total amount of undesired sex endured by women is probably greater in marriage than in prostitution.

I regard [religion] as a disease born of fear and as a source of untold misery to the human race.

A world full of happiness is not beyond human power to create; the obstacles imposed by inanimate nature are not insuperable. The real obstacles lie in the heart of man, and the cure for these is a firm hope, informed and fortified by thought.

The hopes which inspire communism are, in the main, as admirable as those instilled by the Sermon on the Mount, but they are held as fanatically and are as likely to do as much harm.

Mystery is delightful, but unscientific, since it depends upon ignorance.

In science men have discovered an activity of the very highest value in which they are no longer, as in art, dependent for progress upon the appearance of continually greater genius, for in science the successors stand upon the shoulders of their predecessors; where one man of supreme genius has invented a method, a thousand lesser men can apply it.

There is a connected set of events (light-waves) travelling outward from a centre... there are some respects in which all events are alike, and others in which they differ... We must not think of a light-wave as a 'thing', but as a connected group of rhythmical events. The mathematical characteristics of such a group can be inferred by physics, but the intrinsic character of the component events cannot be inferred.

Whatever bitterness and hate may be found in the movements which we are to examine, it is not bitterness or hate, but love, that is their mainspring. It is difficult not to hate those who torture the objects of our love. Though difficult, it is not impossible; but it requires a breadth of outlook and a comprehensiveness of understanding which are not easy to preserve amid a desperate contest. If ultimate wisdom has not always been preserved by Socialists and Anarchists, they have not differed in this from their opponents; and in the source of their inspiration they have shown themselves superior to those who acquiesce ignorantly or supinely in the injustices and oppressions by which the existing system is preserved.

So much of modern mathematical work is obviously on the border-line of logic, so much of modern logic is symbolic and formal, that the very close relationship of logic and mathematics has become obvious to every instructed student. The proof of their identity is, of course, a matter of detail: starting with premisses which would be universally admitted to belong to logic, and arriving by deduction at results which as obviously belong to mathematics, we find that there is no point at which a sharp line can be drawn, with logic to the left and mathematics to the right. If there are still those who do not admit the identity of logic and mathematics, we may challenge them to indicate at what point, in the successive definitions and deductions of Principia Mathematica, they consider that logic ends and mathematics begins. It will then be obvious that any answer must be quite arbitrary.

Passing from quantity to quality of population, we come to the question of eugenics. We may perhaps assume that, if people grow less superstitious, government will acquire the right to sterilize those who are not considered desirable as parents. This power will be used, at first, to diminish imbecility, a most desirable object. But probably, in time, opposition to the government will be taken to prove imbecility, so that rebels of all kinds will be sterilized. Epileptics, consumptives, dipsomaniacs and so on will gradually be included; in the end, there will be a tendency to include all who fail to pass the usual school examinations. The result will be to increase the average intelligence; in the long run, it may be greatly increased. But probably the effect upon really exceptional intelligence will be bad. Mr. Micawber, who was Dickens's father, would hardly have been regarded as a desirable parent. How many imbeciles ought to outweigh one Dickens I do not profess to know.

Reason is a harmonising, controlling force rather than a creative one.

An irrational fear should never be simply let alone, but should be gradually overcome by familiarity with its fainter forms.

Formerly, it was held by philosophers and mathematicians alike that the proofs in Geometry depended on the figure; nowadays, this is known to be false. In the best books there are no figures at all. The reasoning proceeds by the strict rules of formal logic from a set of axioms laid down to begin with.

Those who have been inspired to action by the doctrine of the class war will have acquired the habit of hatred, and will instinctively seek new enemies when the old ones have been vanquished. But in actual fact the psychology of the working man in any of the Western democracies is totally unlike that which is assumed in the Communist Manifesto. He does not by any means feel that he has nothing to lose but his chains, nor indeed is this true. The chains which bind Asia and Africa in subjection to Europe are partly riveted by him. He is himself part of a great system of tyranny and exploitation. Universal freedom would remove, not only his own chains, which are comparatively light, but the far heavier chains which he has helped to fasten upon the subject races of the world.

I think if I had met him [Lenin] without knowing who he was, I should not have guessed that he was a great man; he struck me as too opinionated and narrowly orthodox. His strength comes, I imagine, from his honesty, courage, and unwavering faith-religious faith in the Marxian gospel, which takes the place of the Christian martyr's hopes of Paradise, except that it is less egotistical... I went to Russia a Communist; but contact with those who have no doubts has intensified a thousandfold my own doubts, not as to Communism in itself, but as to the wisdom of holding a creed so firmly that for its sake men are willing to inflict widespread misery.

There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago.

A life devoted to science is therefore a happy life, and its happiness is derived from the very best sources that are open to dwellers on this troubled and passionate planet.

Modern physics... reduces matter to a set of events which proceed outward from a centre. If there is something further in the centre itself, we cannot know about it, and it is irrelevant to physics.

The plan we are advocating amounts essentially to this: that a certain small income, sufficient for necessaries, should be secured to all, whether they work or not, and that a larger income, as much larger as might be warranted by the total amount of commodities produced, should be given to those who are willing to engage in some work which the community recognizes as useful.

People seem good while they are oppressed, but they only wish to become oppressors in their turn: life is nothing but a competition to be the criminal rather than the victim.

The good life is one inspired by love and guided by knowledge.

The theoretical understanding of the world, which is the aim of philosophy, is not a matter of great practical importance to animals, or to savages, or even to most civilized men.

Written words differ from spoken words in being material structures. A spoken word is a process in the physical world, having an essential time-order; a written word is a series of pieces of matter, having an essential space-order.

An extra-terrestrial philosopher, who had watched a single youth up to the age of twenty-one and had never come across any other human being, might conclude that it is the nature of human beings to grow continually taller and wiser in an indefinite progress towards perfection; and this generalisation would be just as well founded as the generalisation which evolutionists base upon the previous history of this planet.

Government by majorities can be made less oppressive by devolution, by placing the decision of questions primarily affecting only a section of the community in the hands of that section, rather than of a Central Chamber. In this way, men are no longer forced to submit to decisions made in a hurry by people mostly ignorant of the matter in hand and not personally interested.

...it [is] possible to suppose that, if Russia is allowed to have peace, an amazing industrial development may take place, making Russia a rival of the United States.

The supreme maxim in scientific philosophising is this: wherever possible, logical constructions are to be substituted for inferred entities.

The scientific attitude of mind involves a sweeping away of all other desires in the interests of the desire to know-it involves suppression of hopes and fears, loves and hates, and the whole subjective emotional life, until we become subdued to the material, able to see it frankly, without preconceptions, without bias, without any wish except to see it as it is, and without any belief that what it is must be determined by some relation, positive or negative, to what we should like it to be, or to what we can easily imagine it to be.

Physics is mathematical not because we know so much about the physical world, but because we know so little: it is only its mathematical properties that we can discover.

Freedom is the greatest of political goods. I do not say freedom is the greatest of all goods: the best things come from within-they are such things as creative art, and love, and thought. Such things can be helped or hindered by political conditions, but not actually produced by them; and freedom is, both in itself and in its relation to these other goods the best thing that political and economic conditions can secure.

In art the Chinese aim at being exquisite, and in life at being reasonable.

We are and irrefutable arbiters of value, and in the world of value Nature is only a part. Thus in this world we are greater than Nature. In the world of values, Nature in itself is neutral, neither good nor bad deserving of neither admiration nor censure. It is we who create value and our desires which confer value. In this realm we are kings, and we debase our kingship if we bow down to Nature. It is for us to determine our good life, not for Nature - not even for Nature personified as God.

When the intensity of emotional conviction subsides, a man who is in the habit of reasoning will search for logical grounds in favour of the belief which he finds in himself.

Our words tend to conceal what is private and particular in our impressions, and to make us believe that different people live in a common world to a greater extent than is in fact the case.

Organic life, we are told, has developed gradually from the protozoon to the philosopher, and this development, we are assured, is indubitably an advance. Unfortunately it is the philosopher, not the protozoon, who gives us this assurance.

The method of "postulating" what we want has many advantages; they are the same as the advantages of theft over honest toil.

One who believes, as I do, that the free intellect is the chief engine of human progress, cannot but be fundamentally opposed to Bolshevism, as much as to the Church of Rome.

All traditional logic habitually assumes that precise symbols are being employed. It is therefore not applicable to this terrestial life but only to an imagined celestial existence... logic takes us nearer to heaven than other studies.

Every great study is not only an end in itself, but also a means of creating and sustaining a lofty habit of mind.

I went to Salt Lake City and the Mormons tried to convert me, but when I found they forbade tea and tobacco I thought it was no religion for me.

Many of the actions by which men have become rich are far more harmful to the community than the obscure crimes of poor men, yet they go unpunished because they do not interfere with the existing order.

The typical Westerner wishes to be the cause of as many changes as possible in his environment; the typical Chinaman wishes to enjoy as much and as delicately as possible.