Happiness is an activity of the soul in accordance with virtue

Since the things we do determine the character of life, no blessed person can become unhappy. For he will never do those things which are hateful and petty.

But what is happiness? If we consider what the function of man is, we find that happiness is a virtuous activity of the soul.

Bring your desires down to your present means. Increase them only when your increased means permit.

Nor need it cause surprise that things disagreeable to the good man should seem pleasant to some men; for mankind is liable to many corruptions and diseases, and the things in question are not really pleasant, but only pleasant to these particular persons, who are in a condition to think them so.

A state of the soul is either (1) an emotion, (2) a capacity, or (3) a disposition; virtue therefore must be one of these three things.

The senses are gateways to the intelligence. There is nothing in the intelligence which did not first pass through the senses.