“Happiness,” the term that Aristotle uses to designate the highest human good, is the usual translation of the Greek eudaimonia. Although it is impossible to abandon the English term at this stage of history, it should be borne in mind that what Aristotle means by eudaimonia is something more like well-being or flourishing than any feeling of contentment. Aristotle argues, in fact, that happiness is activity of the rational soul in accordance with virtue. Human beings must have a function, because particular types of humans (e.g., sculptors) do, as do the parts and organs of individual human beings. This function must be unique to humans; thus, it cannot consist of growth and nourishment, for this is shared by plants, or the life of the senses, for this is shared by animals. It must therefore involve the peculiarly human faculty of reason. The highest human good is the same as good human functioning, and good human functioning is the same as the good exercise of the faculty of reason—that is to say, the activity of rational soul in accordance with virtue. There are two kinds of virtue: moral and intellectual. Moral virtues are exemplified by courage, temperance, and liberality; the key intellectual virtues are wisdom, which governs ethical behaviour, and understanding, which is expressed in scientific endeavour and contemplation.
(Encyclopedia Britannica)
