A man is his own best friend; therefore he ought to love himself best.

The greatest victory is over self.

The more you know, the more you know you don't know.

Hence both women and children must be educated with an eye to the constitution, if indeed it makes any difference to the virtue of a city-state that its children be virtuous, and its women too. And it must make a difference, since half the free population are women, and from children come those who participate in the constitution.

Life is full of chances and changes, and the most prosperous of men may in the evening of his days meet with great misfortunes.

But a man's best friend is the one who not only wishes him well but wishes it for his own sake (even though nobody will ever know it): and this condition is best fulfilled by his attitude towards himself - and similarly with all the other attributes that go to define a friend. For we have said before that all friendly feelings for others are extensions of a man's feelings for himself.

Nothing in life is more necessary than friendship.