Then the Good of Man comes to be "a working of the Soul in the way of Excellence"

From The Ethics of Aristotle.

If then the work of Man is a working of the soul in accordance with reason, or at least not independently of reason, and we say that the work of any given subject, and of that subject good of its kind, are the same in kind (as, for instance, of a harp-player and a good harp-player, and so on in every case, adding to the work eminence in the way of excellence; I mean, the work of a harp-player is to play the harp, and of a good harp-player to play it well); if, I say, this is so, and we assume the work of Man to be life of a certain kind, that is to say a working of the soul, and actions with reason, and of a good man to do these things well and nobly, and in fact everything is finished off well in the way of the excellence which peculiarly belongs to it: if all this is so, then the Good of Man comes to be "a working of the Soul in the way of Excellence," or, if Excellence admits of degrees, in the way of the best and most perfect Excellence.

And we must add, in a complete life; for as it is not one swallow or one fine day that makes a spring, so it is not one day or a short time that makes a man blessed and happy.