Aristotle could have avoided the mistake of thinking that women have fewer teeth than men, by the simple device of asking Mrs. Aristotle to keep her mouth open while he counted.

Boredom is... a vital problem for the moralist, since half the sins of mankind are caused by the fear of it.

Drunkenness is temporary suicide.

Aristotle maintained that women have fewer teeth than men; although he was twice married, it never occurred to him to verify this statement by examining his wives' mouths.

Most people would sooner die than think; in fact, they do so.

I say quite deliberately that the Christian religion, as organized in its Churches, has been and still is the principal enemy of moral progress in the world.

No one gossips about other people's secret virtues.

Men are born ignorant, not stupid. They are made stupid by education.

The secret of happiness is this: let your interests be as wide as possible, and let your reactions to the things and persons that interest you be as far as possible friendly rather than hostile.

No; we have been as usual asking the wrong question. It does not matter a hoot what the mockingbird on the chimney is singing. The real and proper question is: Why is it beautiful?

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.

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

It has been said that man is a rational animal. All my life I have been searching for evidence which could support this.

Admiration of the proletariat, like that of dams, power stations, and aeroplanes, is part of the ideology of the machine age.

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 civilised men.

Freedom comes only to those who no longer ask of life that it shall yield them any of those personal goods that are subject to the mutations of time.

Against my will, in the course of my travels, the belief that everything worth knowing was known at Cambridge gradually wore off. In this respect my travels were very useful to me.

Religions that teach brotherly love have been used as an excuse for persecution, and our profoundest scientific insight is made into a means of mass destruction.

Of all forms of caution, caution in love is perhaps the most fatal to true happiness.

The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd.

Dogmatism and skepticism are both, in a sense, absolute philosophies; one is certain of knowing, the other of not knowing. What philosophy should dissipate is certainty, whether of knowledge or ignorance.

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.

Why is propaganda so much more successful when it stirs up hatred than when it tries to stir up friendly feeling?

In America everybody is of the opinion that he has no social superiors, since all men are equal, but he does not admit that he has no social inferiors, for, from the time of Jefferson onward, the doctrine that all men are equal applies only upwards, not downwards.

With the introduction of agriculture mankind entered upon a long period of meanness, misery, and madness, from which they are only now being freed by the beneficent operation of the machine.

A process which led from the amoeba to man appeared to the philosophers to be obviously a progress though whether the amoeba would agree with this opinion is not known.

I remain convinced that obstinate addiction to ordinary language in our private thoughts is one of the main obstacles to progress in philosophy.

Order, unity, and continuity are human inventions, just as truly as catalogues and encyclopedias.

The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as poetry.

It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly.

The most savage controversies are about matters as to which there is no good evidence either way.

Do not fear to be eccentric in opinion, for every opinion now accepted was once eccentric.

To acquire immunity to eloquence is of the utmost importance to the citizens of a democracy.

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.

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

If there were in the world today any large number of people who desired their own happiness more than they desired the unhappiness of others, we could have a paradise in a few years.

All movements go too far.

The slave is doomed to worship time and fate and death, because they are greater than anything he finds in himself, and because all his thoughts are of things which they devour.

Conventional people are roused to fury by departure from convention, largely because they regard such departure as a criticism of themselves.

The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.

Liberty is the right to do what I like; license, the right to do what you like.

The time you enjoy wasting is not wasted time.

Religion is something left over from the infancy of our intelligence, it will fade away as we adopt reason and science as our guidelines.

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

None but a coward dares to boast that he has never known fear.

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.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

A hallucination is a fact, not an error; what is erroneous is a judgment based upon it.

A truer image of the world, I think, is obtained by picturing things as entering into the stream of time from an eternal world outside, than from a view which regards time as the devouring tyrant of all that is.