In NDPR, Christopher P. Long reviews
Aryeh Kosman's The Activity of Being: An Essay on Aristotle's Ontology
Kosman suggests, and rightly, that "the choice of substance as the primary mode of being is not as arbitrary and tendentious as it sounds. . . . It is [ousia's] translation as substance that is the tendentious move". This can be heard, however, only if we attend to the word in its ancient sense, as what is most one's own -- not only one's property, though also that -- but more significantly, the conditioned habits of being what one really is. Heidegger is helpful in this regard: "What is characteristic of the customary meaning is that not only does it express a being, but a being in the how of its being." Thus, the direction to which Aristotle points at the beginning of his inquiry into being is toward a being in the how of its being, toward a determinate being doing what it does, being what it is -- ousia.