Happiness is a quality of the soul...not a function of one's material circumstances.

There are branches of learning and education which we must study merely with a view to leisure spent in intellectual activity, and these are to be valued for their own sake; whereas those kinds of knowledge which are useful in business are to be deemed necessary, and exist for the sake of other things.

Character is that which reveals moral purpose, exposing the class of things a man chooses and avoids.

The structural unity of the parts is such that, if any one of them is displaced or removed, the whole will be disjointed and dis­turbed. For a thing whose presence or absence makes no visible difference is not an organic part of the whole.

It [Justice] is complete virtue in the fullest sense, because it is the active exercise of complete virtue; and it is complete because its possessor can exercise it in relation to another person, and not only by himself.

But then in what way are things called good? They do not seem to be like the things that only chance to have the same name. Are goods one then by being derived from one good or by all contributing to one good, or are they rather one by analogy? Certainly as sight is in the body, so is reason in the soul, and so on in other cases.

The energy of the mind is the essence of life.