Man is a wingless animal with two feet and flat nails.

One of the penalties for refusing to participate in politics is that you end up being governed by your inferiors.

The science [geometry] is pursued for the sake of the knowledge of what eternally exists, and not of what comes for a moment into existence, and then perishes.

Let no-one ignorant of geometry enter. Said to have been inscribed above the door of Plato's Academy.

Virtue is the desire of things honourable and the power of attaining them.

[M]ere knowledge of the truth will not give you the art of persuasion.

I must yield to you, for you are irresistible.