Energeia
ἐνέργεια (energeia)
The act, the activity, the being in exercise—as opposed to mere capacity or possession that remains inert. Aristotle refuses to place the supreme good in a quality one might have without using it: capacity can exist in a man who sleeps without producing anything, whereas the act itself necessarily acts and acts well. Happiness is thus not a having but a doing: the activity of the soul guided by virtue, unfolding over an entire life. To be distinguished from the dormant disposition (*hexis* unexercised) and from *eudaimonia*, which is precisely this accomplished activity, not a state one possesses at rest.
Mais il n'est pas du tout indifférent de placer le bien suprême dans la possession ou dans l'usage de certaines qualités, dans la simple aptitude ou dans l'acte lui-même. L'aptitude peut exister fort réellement sans produire aucun bien, comme par exemple dans un homme qui dort, ou dans un homme qui pour toute autre cause reste inactif. L'acte au contraire ne peut jamais être dans ce cas, puisqu'il agit nécessairement, et que de plus il agit bien.
The Greek word energeia (ἐνέργεια)—coined by Aristotle from ergon, meaning “work” or “deed”—refers to being in action, as opposed to what remains merely potential or possessed without use. Barthélemy-Saint-Hilaire translates it as “act” or “activity.” It marks one of philosophy’s most decisive distinctions: between what a thing can do and what it actually does, between dormant quality and quality at work.
Aristotle uses it to settle the question of happiness. Possessing virtue is not enough; one must also exercise it. “Capacity may exist quite genuinely without producing any good, as in a man who sleeps”—the finest disposition, when inactive, is worthless until it acts. The act, by contrast, “necessarily acts, and moreover acts well.” Human flourishing, then, is not a hoarded treasure but a putting-into-practice.
Hence his comparison to the Olympic Games: the crown does not go to the most beautiful or the strongest, but to those who enter the contest, for victors are found only among competitors. Likewise, those who act well—not merely those who could—are the ones who may claim a happy life. The proper good of man, he concludes, is “the activity of the soul guided by virtue”—and, if there are many virtues, by the highest. Prudence governs this activity in particular cases; the magnanimous elevates it to its full stature.
Energeia ≠ mere possession: virtue held but not exercised sleeps like a sleeping man, producing no good. Energeia ≠ hexis: the one is the acquired, stable state one possesses; the other is its enactment, the exercise that alone yields the deed. And eudaimonia is not something one has—it is this activity of the soul in accordance with virtue, sustained “throughout a complete and entire life”—for one swallow does not make a spring.