In pondering the implications of Aubry’s narrower construal of form in Aristotle, an important case to consider is the classic definition of soul. The standard scholastic “soul is the form of the body” does in fact ultimately refer to Aristotle’s more precise statement in On the Soul book 2 chapter 1 that “soul is an entelechy of the first kind of a natural body having life as a potentiality” (Sachs tr., p. 82, modified). Entelechy is a strictly more powerful concept than form.
Plato calls the soul a form, but I always found it difficult to reconcile the soul’s apparent diverse activity in life with what Plato says about the eternal and apparently static nature of form.
On the other hand, Aristotle begins the chapter mentioned above by distinguishing form, matter, and the composite. And he says, “Therefore it is necessary that the soul has its thinghood [ousia] as the form of a natural body having life as a potency. But this sort of thinghood is a being-at-work-staying-itself [entelechy]; therefore the soul is the being-at-work-staying-itself of such a body” (p. 81, emphasis added).
Clearly, the quote I opened with is a more precise version of this, following Aristotle’s frequent pattern of first mentioning something in more colloquial terms, before offering a more definitive formulation of it.
The opening distinction of form, matter, and composite is even presented as a division of ousia. But Aristotle’s authoritative and in-depth discussion of ousia in book Zeta of the Metaphysics begins by distinguishing at least four senses of ousia, only one of which is an “underlying thing” (primary substance in the sense of the Categories). Then only “in a certain way” (ch. 3, Sachs tr., p. 119) are matter and form said to be of that sort. And the “underlying thing” sense is the one that is most left behind in Aristotle’s long development of what ousia really is.
Next in this series: Substance, Essence, Form
The Postmodern Peripatetic 