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.

To create a healthy philosophy you should renounce metaphysics but be a good mathematician.

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 has made them.

Pure mathematics consists entirely of assertions to the effect that, if such and such a proposition is true of anything, then suchand such another proposition is true of that thing.... 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.

Do not feel envious of the happiness of those who live in a fool's paradise, for only a fool will think that is happiness.

Unfortunately, however, power is sweet, and the man who in the beginning seeks power merely in order to have scope for his benevolence is likely, before long, to love the power for its own sake.

I used often to go to America during Prohibition, and there was far more drunkenness there then than before; the prohibition of pornography has much the same effect.