d will are one mind."

_I answer that,_ Since it is of the nature of the memory to preserve
the species of those things which are not actually apprehended, we
must first of all consider whether the intelligible species can thus
be preserved in the intellect: because Avicenna held that this was
impossible. For he admitted that this could happen in the sensitive
part, as to some powers, inasmuch as they are acts of corporeal
organs, in which certain species may be preserved apart from actual
apprehension. But in the intellect, which has no corporeal organ,
nothing but what is intelligible exists. Wherefore every thing of
which the likeness exists in the intellect must be actually
understood. Thus, therefore, according to him, as soon as we cease to
understand something actually, the species of that thing ceases to be
in our intellect, and if we wish to understand that thing anew, we
must turn to the active intellect, which he held to be a separate
substance, in order that the intelligible species may thence flow
again into our passive intellect. And from the practice and habit of
turning to the active intellect there is formed, according to him, a
certain aptitude in the passive intellect for turning to the active
intellect; which aptitude he calls the habit of knowledge. According,
therefore, to this supposition, nothing is preserved in the
intellectual part that is not actually understood: wherefore it would
not be possible to admit memory in the intellectual part.

But this opinion is clearly opposed to the teaching of Aristotle.
For he says (De Anima iii, 4) that, when the passive intellect "is
identified with each thing as knowing it, it is said to be in act,"
and that "this happens when it can operate of itself. And, even then,
it is in potentiality, but not in the same way as before learning and
discovering." Now, the passive intellect is said to be each thing,
inasmuch as it receives the intelligible species of each thing. To
the fact, therefore, that it receives the species of intelligible
things it owes its being able to operate when it wills, but not so
that it be always operating: for even then is it in potentiality in
a certain sense, though otherwise than before the act of
understanding--namely, in the sense that whoever has habitual
knowledge is in potentiality to actual consideration.

The foregoing opinion is also opposed to reason. For what is received
into something is received according to the condi