Every community is an association of some kind and every community is established with a view to some good; for everyone always acts in order to obtain that which they think good. But, if all communities aim at some good, the state or political community, which is the highest of all, and which embraces all the rest, aims at good in a greater degree than any other, and at the highest good.

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

No one chooses what does not rest with himself, but only what he thinks can be attained by his own act.

That which is common to the greatest number has the least care bestowed upon it. Every one thinks chiefly of his own, hardly at all of the common interest; and only when he is himself concerned as an individual. For besides other considerations, everybody is more inclined to neglect the duty which he expects another to fulfill.

... a science must deal with a subject and its properties.

The virtue of the good man is necessarily the same as the virtue of the citizen of the perfect state.

It has been well said that 'he who has never learned to obey cannot be a good commander.' The two are not the same, but the good citizen ought to be capable of both; he should know how to govern like a freeman, and how to obey like a freeman - these are the virtues of a citizen.