Knowledge is true opinion.

If we are to keep our flock at the highest pitch of excellence, there should be as many unions of the best of both sexes, and as few of the inferior as possible, and that only the offspring of the better unions should be kept.

A State would be happy where philosophers were kings, or kings philosophers.

He who without the Muse's madness in his soul comes knocking at the door of poesy and thinks that art will make him anything fit to be called a poet, finds that the poetry which he indites in his sober senses is beaten hollow by the poetry of madmen.

The first and the best victory is to conquer self.

Rhythm and melody enter into the soul of the well-instructed youth and produce there a certain mental harmony hardly obtainable in any other way. . . . thus music, too, is concerned with the principles of love in their application to harmony and rhythm.

Necessity is literally the mother of invention.