A wise man speaks because he has something to say; a fool because he has to say something.

Mathematics is the language in which the gods talk to people.

Either we shall find what it is we are seeking or at least we shall free ourselves from the persuasion that we know what we do not know.

Seven years of silent inquiry are needful for a man to learn the truth, but fourteen in order to learn how to make it known to his fellow-men.

The good man is the only excellent musician, because he gives forth a perfect harmony not with a lyre or other instrument but with the whole of his life.

Let him know how to choose the mean and avoid the extremes on either side, as far as possible. . . . For this is the way of happiness.

The good, of course, is always beautiful, and the beautiful never lacks proportion.