To modern educated people, it seems obvious that matters of fact are to be ascertained by observation, not by consulting ancient authorities. But this is an entirely modern conception, which hardly existed before the seventeenth century.

Religion may in most of its forms be defined as the belief that the gods are on the side of the government.

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. ... In art nothing worth doing can be done without genius; in science even a very moderate capacity can contribute to a supreme achievement.

We do not like to be robbed of an enemy; we want someone to hate when we suffer. It is so depressing to think that we suffer because we are fools; yet, taking mankind in the mass, that is the truth.

One is often told that it is a very wrong thing to attack religion, because religion makes men virtuous. So I am told; I have not noticed it.

My sad conviction is that people can only agree about what they're not really interested in.

The true spirit of delight...is to be found in mathematics as surely as in poetry.