Only mathematics and mathematical logic can say as little as the physicist means to say.

The modern man thinks that everything ought to be done for the sake of something else, and never for its own sake.

The luxury to disparage freedom is the privilege of those who already possess it.

Altogether it will be found that a quiet life is characteristic of great men, and that their pleasures have not been of the sort that would look exciting to the outward eye.

Moral indignation is one of the most harmful forces in the modern world, the more so as it can always be diverted to sinister uses by those who control propaganda.

The first step in wisdom, as well as in morality, is to open the windows of the ego as wide as possible.

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