I can show you that the art of calculation has to do with odd and even numbers in their numerical relations to themselves and to each other.

Those wretches who never have experienced the sweets of wisdom and virtue, but spend all their time in revels and debauches, sink downward day after day, and make their whole life one continued series of errors.

At the Egyptian city of Naucratis there was a famous old god whose name was Theuth; the bird which is called the Ibis was sacred to him, and he was the inventor of many arts, such as arithmetic and calculation and geometry and astronomy and draughts and dice, but his great discovery was the use of letters.

And so, when a person meets the half that is his very own, whatever his orientation, whether it's to young men or not, then something wonderful happens: the two are struck from their senses by love, by a sense of belonging to one another, and by desire, and they don't want to be separated from one another, not even for a moment.

To do injustice is the greatest of all evils.

Mathematics is like draughts in being suitable for the young, not too difficult, amusing, and without peril to the state.

Of all the animals, the boy is the most unmanageable.