le in the soul. For the soul by its very essence
is an act. Therefore if the very essence of the soul were the
immediate principle of operation, whatever has a soul would always
have actual vital actions, as that which has a soul is always an
actually living thing. For as a form the soul is not an act ordained
to a further act, but the ultimate term of generation. Wherefore,
for it to be in potentiality to another act, does not belong to it
according to its essence, as a form, but according to its power. So
the soul itself, as the subject of its power, is called the first
act, with a further relation to the second act. Now we observe that
what has a soul is not always actual with respect to its vital
operations; whence also it is said in the definition of the soul,
that it is "the act of a body having life potentially"; which
potentiality, however, "does not exclude the soul." Therefore it
follows that the essence of the soul is not its power. For nothing
is in potentiality by reason of an act, as act.

Reply Obj. 1: Augustine is speaking of the mind as it knows and loves
itself. Thus knowledge and love as referred to the soul as known and
loved, are substantially or essentially in the soul, for the very
substance or essence of the soul is known and loved. In the same way
are we to understand what he says in the other passage, that those
things are "one life, one mind, one essence." Or, as some say, this
passage is true in the sense in which the potential whole is
predicated of its parts, being midway between the universal whole,
and the integral whole. For the universal whole is in each part
according to its entire essence and power; as animal in a man and in
a horse; and therefore it is properly predicated of each part. But
the integral whole is not in each part, neither according to its
whole essence, nor according to its whole power. Therefore in no way
can it be predicated of each part; yet in a way it is predicated,
though improperly, of all the parts together; as if we were to say
that the wall, roof, and foundations are a house. But the potential
whole is in each part according to its whole essence, not, however,
according to its whole power. Therefore in a way it can be predicated
of each part, but not so properly as the universal whole. In this
sense, Augustine says that the memory, understanding, and the will
are the one essence of the soul.

Reply Obj. 2: The act to which primary matter is in potentiality