Any polis which is truly so called, and is not merely one in name, must devote itself to the end of encouraging goodness. Otherwise, political association sinks into a mere alliance.
The man who is isolated, who is unable to share in the benefits of political association, or has no need to share because he is already self-sufficient, is no part of the polis, and must therefore be either a beast or a god.
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.
Some kinds of animals burrow in the ground; others do not. Some animals are nocturnal, as the owl and the bat; others use the hours of daylight. There are tame animals and wild animals. Man and the mule are always tame; the leopard and the wolf are invariably wild, and others, as the elephant, are easily tamed.
Thus we must advance from generalities to particulars; for it is a whole that is best known to sense-perception, (25) and a generality is a kind of whole, comprehending many things within it, like parts.