In science, as in art, and, as I believe, in every other sphere of human activity, there may be wisdom in a multitude of counsellors, but it is only in one or two of them.

The population question is the real riddle of the sphinx, to which no political Oedipus has as yet found the answer. In view of the ravages of the terrible monster over-multiplication, all other riddle sink into insignificance.

The chess-board is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

Every great advance in natural knowledge has involved the absolute rejection of authority.

It is the first duty of a hypothesis to be intelligible.

It is not who is right, but what is right, that is of importance.