The same thing may have all the kinds of causes, e.g. the moving cause of a house is the art or the builder, the final cause is the function it fulfils, the matter is earth and stones, and the form is the definitory formula.

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.

Jealousy is both reasonable and belongs to reasonable men, while envy is base and belongs to the base, for the one makes himself get good things by jealousy, while the other does not allow his neighbour to have them through envy.

The excellence of a thing is related to its proper function.

One thing alone not even God can do,To make undone whatever hath been done.

He who can be, and therefore is, another's, and he who participates in reason enough to apprehend, but not to have, is a slave by nature.

Now property is part of a household, and the acquisition of property part of household-management; for neither life itself nor the good life is possible without a certain minimum supply of the necessities.