A sense of duty is useful in work but offensive in personal relations. People wish to be liked, not to be endured with patient resignation.

Mathematics is, I believe, the chief source of the belief in eternal and exact truth, as well as a sensible intelligible world.

I think the subject which will be of most importance politically is Mass Psychology... Its importance has been enormously increased by the growth of modern methods of propaganda. Although this science will be diligently studied, it will be rigidly confined to the governing class. The populace will not be allowed to know how its convictions are generated.

It is not my prayer and humility that you cause things to go as you wish, but by acquiring a knowledge of natural laws.

The problem with the wise is they are so filled with doubts while the dull are so certain.

When conscious activity is wholly concentrated on some one definite purpose, the ultimate result, for most people, is lack of balance accompanied by some form of nervous disorder.

It seems to us unwise to have insisted on teaching geometry to the younger Dionysius, tyrant of Syracuse, in order to make him a good king, but from Plato's point of view it was essential. He was sufficiently Pythagorean to think that without mathematics no true wisdom is possible.