What we know is not capable of being otherwise; of things capable of being otherwise we do not know, when they have passed outsideour observation, whether they exist or not. Therefore the object of knowledge is of necessity. Therefore it is eternal; for things that are of necessity in the unqualified sense are all eternal; and things that are eternal are ungenerated and imperishable.

In inventing a model we may assume what we wish, but should avoid impossibilities.

Worthless persons appointed to have supreme control of weighty affairs do a lot of damage.

Comedy has had no history, because it was not at first treated seriously.

There are, then, these three means of effecting persuasion. The man who is to be in command of them must, it is clear, be able (1) to reason logically, (2) to understand human character and goodness in their various forms, and (3) to understand the emotions--that is, to name them and describe them, to know their causes and the way in which they are excited.

In general, what is written must be easy to read and easy to speak; which is the same.

The secret to humor is surprise.