The perfection of the form of a thing is its entelechy (ivr€AMXECa) in virtue of which it attains its fullest realization of function (De anima, Í.
Thus the entelechy of the body is the soul.
The soul is created by God when the body of which it is the entelechy is prepared for it.
Psychologically, Aristotle applied his dualism of matter and form to explain the antithesis of body and soul, so that the soul is the form, or entelechy, of an organic body, and he applied the same dualism to explain sensation, which he supposed to be reception of the sensible form or essence, without the matter, of a body, e.g.
Dicaearchus agreed with his friend in this naturalistic rendering of the Aristotelian entelechy, and is recorded to have argued formally against the immortality of the soul.