The physician himself, if sick, actually calls in another physician, knowing that he cannot reason correctly if required to judge his own condition while suffering.

All three states - the Lacedaemonian, the Cretan, and the Carthaginian - nearly resemble one another, and are very different from any others. Many of the Carthaginian institutions are excellent. The superiority of their constitution is proved by the fact that the common people remains loyal to the constitution; the Carthaginians have never had any rebellion worth speaking of, and have never been under the rule of a tyrant.

Metaphysics is universal and is exclusively concerned with primary substance. ... And here we will have the science to study that which is, both in its essence and in the properties which it has.

A human being is a naturally political [animal].

The most perfect political community is one in which the middle class is in control, and outnumbers both of the other classes.

All friendly feelings toward others come from the friendly feelings a person has for himself.

The greatest virtues are those which are most useful to other persons.