It is the characteristic of the magnanimous man to ask no favor but to be ready to do kindness to others.

Pleasure causes us to do base actions and pain causes us to abstain from doing noble actions.

If every tool, when ordered, or even of its own accord, could do the work that befits it... then there would be no need either of apprentices for the master workers or of slaves for the lords.

There is nothing strange in the circle being the origin of any and every marvel.

One cannot say of something that it is and that it is not in the same respect at the same time.

We do not know a truth without knowing its cause.

The secret to humor is surprise.