On The Soul
case of mind thought about an object that is highly intelligible
renders it more and not less able afterwards to think objects that are
less intelligible: the reason is that while the faculty of sensation
is dependent upon the body, mind is separable from it.
Once the mind has become each set of its possible objects, as a
man of science has, when this phrase is used of one who is actually
a man of science (this happens when he is now able to exercise the
power on his own initiative), its condition is still one of
potentiality, but in a different sense from the potentiality which
preceded the acquisition of knowledge by learning or discovery: the
mind too is then able to think itself.
Since we can distinguish between a spatial magnitude and what it
is to be such, and between water and what it is to be water, and so in
many other cases (though not in all; for in certain cases the thing
and its form are identical), flesh and what it is to be flesh are
discriminated either by different faculties, or by the same faculty in
two different states: for flesh necessarily involves matter and is
like what is snub-nosed, a this in a this. Now it is by means of the
sensitive faculty that we discriminate the hot and the cold, i.e.
the factors which combined in a certain ratio constitute flesh: the
essential character of flesh is apprehended by something different
either wholly separate from the sensitive faculty or related to it
as a bent line to the same line when it has been straightened out.
Again in the case of abstract objects what is straight is
analogous to what is snub-nosed; for it necessarily implies a
continuum as its matter: its constitutive essence is different, if
we may distinguish between straightness and what is straight: let us
take it to be two-ness. It must be apprehended, therefore, by a
different power or by the same power in a different state. To sum
up, in so far as the realities it knows are capable of being separated
from their matter, so it is also with the powers of mind.
The problem might be suggested: if thinking is a passive