"In the Nichomachean Ethics, Aristotle develops a theory of the good life (eudiamonia) for humans. “Eudiamonia” is perhaps best translated as flourishing or living well and doing well. So when Aristotle speaks of the good life as the happy life, he does not mean that the good life is merely one of feeling happy or amused. Rather ... the good life for a person is the active life of functioning well in those ways that are essential and unique to humans."

Sources:

Aristotle: Nicomachean Ethics

http://facweb.bcc.ctc... (the above quote if from this article)

http://en.wikipedia.o...