Since we think we understand when we know the explanation, and there are four types of explanation (one, what it is to be a thing; one, that if certain things hold it is necessary that this does; another, what initiated the change; and fourth, the aim), all these are proved through the middle term.

Boundaries don't protect rivers, people do.

In the Laws it is maintained that the best constitution is made up of democracy and tyranny, which are either not constitutions at all, or are the worst of all. But they are nearer the truth who combine many forms; for the constitution is better which is made up of more numerous elements. The constitution proposed in the Laws has no element of monarchy at all; it is nothing but oligarchy and democracy, leaning rather to oligarchy.

It is just that we should be grateful, not only to those with whose views we may agree, but also to those who have expressed more superficial views; for these also contributed something, by developing before us the powers of thought.

The high-minded man must care more for the truth than for what people think.

I will not allow the Athenians to sin twice against philosophy.

Metaphor is halfway between the unintelligible and the commonplace.