Aristotle on the human good

If the function of man is an activity of soul [...] and if we say ‘a so-and-so’ and ‘a good so-and-so’ [...] (e.g. a lyre player and a good lyre player), and so without qualification in all cases, eminence in respect of goodness being added to the name of the function (for the function of a lyre player is to play the lyre, and that of a good lyre player is to do so well) — if this is the case, and we state the function of man to be a certain kind of life, and this to be an activity or actions of the soul [...], and the function of a good man to be the good and noble performance of these [...] — if this is the case, human good turns out to be activity of soul exhibiting excellence.”

Aristotle Nicomachean Ethics I. 7