You should never think without an image.

We have no evidence as yet about mind or the power to think; it seems to be a widely different kind of soul, differing as what is eternal from what is perishable; it alone is capable of existence in isolation from all other psychic powers.

All persons ought to endeavor to follow what is right, and not what is established.

Again, it is possible to fail in many ways (for evil belongs to the class of the unlimited and good to that of the limited), while to succeed is possible only in one way (for which reason also one is easy and the other difficult—to miss the mark easy, to hit it difficult); for these reasons also, then, excess and defect are characteristic of vice, and the mean of virtue; For men are good in but one way, but bad in many.

The young are heated by Nature as drunken men by wine.

He is his own best friend and takes delight in privacy whereas the man of no virtue or ability is his own worst enemy and is afraid of solitude.

The tyrant, who in order to hold his power, suppresses every superiority, does away with good men, forbids education and light, controls every movement of the citizens and, keeping them under a perpetual servitude, wants them to grow accustomed to baseness and cowardice, has his spies everywhere to listen to what is said in the meetings, and spreads dissension and calumny among the citizens and impoverishes them, is obliged to make war in order to keep his subjects occupied and impose on them permanent need of a chief.