Full Idea
We define the happy man as 'one who is active in accordance with complete virtue, and who is adequately furnished with external goods, and that not for some unspecified period but throughout a complete life'.
Gist of Idea
Happiness is activity in accordance with complete virtue, for a whole life, with adequate external goods
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1101a13)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.84
A Reaction
The only plausible objection to this definition is that it sounds worthy but dull. There is some exciting, romantic, Nietzschean ingredient missing - but the happy man will routinely perform 'fine deeds', and these may involve novelty and boldness.