“Every art and every inquiry, and similarly every action as well as choice, is held to aim at some good. …
Now, since there are many actions, arts, and sciences,4 the ends too are many: of medicine, the end is health; of shipbuilding, a ship; of generalship, victory; of household management, wealth. …
If, therefore, there is some end of our actions that we wish for on account of itself, the rest being things we wish for on account of this end, and if we do not choose all things on account of something else—for in this way the process will go on infinitely such that the longing involved is empty and pointless—clearly this would be the good, that is, the best.
And with a view to our life, then, is not the knowledge of this good of great weight, and would we not, like archers in possession of a target, better hit on what is needed? If this is so, then one must try to grasp, in outline at least, whatever it is and to which of the sciences or capacities it belongs.” (Aristotle, Nicomachean Ethics, I.1,2)
Aristotle on happiness as the ultimate good