Nicomachean Ethics

Every art, and every science reduced to a teachable form, and in like manner every action and moral choice, aims, it is thought, at some good: for which reason a common and by no means a bad description of the Chief Good is, “that which all things aim at.”

Now there plainly is a difference in the Ends proposed: for in some cases they are acts of working, and in others certain works or tangible results beyond and beside the acts of working: and where there are certain Ends beyond and beside the actions, the works are in their nature better than the acts of working. Again, since actions and arts and sciences are many, the Ends likewise come to be many: of the healing art, for instance, health; of the ship-building art, a vessel; of the military art, victory; and of domestic management, wealth; are respectively the Ends.

And whatever of such actions, arts, or sciences range under some one faculty (as under that of horsemanship the art of making bridles, and all that are connected with the manufacture of horse-furniture in general; this itself again, and every action connected with war, under the military art; and in the same way others under others), in all such, the Ends of the master-arts are more choice-worthy than those ranging under them, because it is with a view to the former that the latter are pursued.