No man should bring children into the world who is unwilling to persevere to the end in their nature and education.

Man is a biped without feathers.

All knowledge is but remembrance.

They ought to be gentle to their friends and dangerous to their enemies.

One cannot make a slave of a free person, for a free person is free even in a prison.

Cunning... is but the low mimic of wisdom.

And tell him it's quite true that the best of the philosophers are of no use to their fellows; but that he should blame, not the philosophers, but those who fail to make use of them.