Justice is a certain rectitude of mind whereby a man does what he ought to do in the circumstances confronting him.

If... the motion of the earth were circular, it would be violent and contrary to nature, and could not be eternal, since ... nothing violent is eternal .... It follows, therefore, that the earth is not moved with a circular motion.

The knowledge of God is the cause of things. For the knowledge of God is to all creatures what the knowledge of the artificer is to things made by his art.

Sorrow can be alleviated by good sleep, a bath and a glass of wine.

It must be understood that prime matter, and form as well, is neither generated nor corrupted, because every generation is from something to something. Now that from which generation proceeds is matter, and that to which it proceeds is form. So that, if matter or form were generated, there would be a matter for matter and a form for form, endlessly. Whence, there is generation only of the composite, properly speaking.

Friendship is the source of the greatest pleasures, and without friends even the most agreeable pursuits become tedious.

It is not possible to be ignorant of the end of things if we know their beginning.