Wise men talk because they have something to say; Fools, because they have to say something. - Plato

Parmenides: I was pleased with you, Socrates, because you would not discuss the doubtful question in terms of visible objects or in relation to them, but only with reference to what we conceive most entirely by the intellect and may call ideas… But if you wish to get better training, you must do something more than that; you must consider not only what happens if a particular hypothesis is true, but also what happens if it is not true.

States will never be happy until rulers become philosophers or philosophers become rulers.

Whereas the truth is that the State in which the rulers are most reluctant to govern is always the best and most quietly governed, and the State in which they are most eager, the worst.