Aristotle’s text in the De Anima
On the Soul,
III, 4, 429a10-429b9
to the part of the soul with which the soul knows and thinks
(whether this is separable from the others in definition only,
or spatially as well) we have to inquire (1) what differentiates
this part, and (2) how thinking can take place.
is like perceiving, it must be either a process in which the
soul is acted upon by what is capable of being thought, or
a process different from but analogous to that. The thinking
part of the soul must therefore be, while impassible, capable
of receiving the form of an object; that is, must be potentially
identical in character with its object without being the object.
Mind must be related to what is thinkable, as sense is to
what is sensible.
since everything is a possible object of thought, mind in
order, as Anaxagoras says, to dominate, that is, to know,
must be pure from all admixture; for the co-presence of what
is alien to its nature is a hindrance and a block: it follows
that it too, like the sensitive part, can have no nature of
its own, other than that of having a certain capacity. Thus
that in the soul which is called mind (by mind I mean that
whereby the soul thinks and judges) is, before it thinks,
not actually any real thing. For this reason it cannot reasonably
be regarded as blended with the body: if so, it would acquire
some quality, e.g. warmth or cold, or even have an organ like
the sensitive faculty: as it is, it has none. It was a good
idea to call the soul ‘the place of forms’, though (1) this
description holds only of the intellective soul, and (2) even
this is the forms only potentially, not actually.
of the sense-organs and their employment reveals a distinction
between the impassibility of the sensitive and that of the
intellective faculty. After strong stimulation of a sense
we are less able to exercise it than before, as e.g. in the
case of a loud sound we cannot hear easily immediately after,
or in the case of a bright colour or a powerful odour we cannot
see or smell, but in the 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.”
(trad. by J. A. Smith)
of this text:
Thinking is like perceiving: namely, (a) whatever
thinks or perceives, while impassible, is capable of receiving
the form of an object; (b) it is potentially similar in character
with its object without being the object.
Aristotle’s conclusion is that “intellect (nous)”
is “pure from all admixture,” “cannot reasonably be regarded
as blended with the body,” and “is separable from it.” The
stress here is on being separable. [It is important to highlight
that Aristotle’s conclusion does not concern the “person,”
and not even the “soul” as such or the “human subject;” it
just addresses what he calls “intellect”.]
main argument is that (a) “everything is a possible object
of thought,” (b) so intellect must be pure “for the co-presence
of what is alien to its nature is a hindrance and a block”.
Supporting argument: the strong stimulation of the
faculty of thought does not diminish the thinking ability;
on the contrary, it increases it.
clarification: “impassible,” in Aristotle’s text, means that
something is capable of receiving the form of something else
without a substantial change in its own form (knowledge is
an accidental change).
be indeterminate in order to receive every kind of
form. The analogy with the concept of “prime matter” can help.
Prime matter, though, is not impassible. The analogy with
sensory knowledge is helpful too. Sensory knowledge, though,
can receive only bodily forms given by the images, and it
is not perfectly impassible (see the fourth point about Aristotle’s