Whether Our Intellect Understands Corporeal and Material Things by
Abstraction from Phantasms?
Objection 1: It would seem that our intellect does not understand
corporeal and material things by abstraction from the phantasms. For
the intellect is false if it understands an object otherwise than as
it really is. Now the forms of material things do not exist as
abstracted from the particular things represented by the phantasms.
Therefore, if we understand material things by abstraction of the
species from the phantasm, there will be error in the intellect.
Obj. 2: Further, material things are those natural things which
include matter in their definition. But nothing can be understood
apart from that which enters into its definition. Therefore material
things cannot be understood apart from matter. Now matter is the
principle of individualization. Therefore material things cannot be
understood by abstraction of the universal from the particular, which
is the process whereby the intelligible species is abstracted from the
phantasm.
Obj. 3: Further, the Philosopher says (De Anima iii, 7) that the
phantasm is to the intellectual soul what color is to the sight. But
seeing is not caused by abstraction of species from color, but by
color impressing itself on the sight. Therefore neither does the act
of understanding take place by abstraction of something from the
phantasm, but by the phantasm impressing itself on the intellect.
Obj. 4: Further, the Philosopher says (De Anima iii, 5) there are
two things in the intellectual soul--the passive intellect and the
active intellect. But it does not belong to the passive intellect to
abstract the intelligible species from the phantasm, but to receive
them when abstracted. Neither does it seem to be the function of the
active intellect, which is related to the phantasm, as light is to
color; since light does not abstract anything from color, but rather
streams on to it. Therefore in no way do we understand by abstraction
from phantasms.
Obj. 5: Further, the Philosopher (De Anima iii, 7) says that "the
intellect understands the species in the phantasm"; and not,
therefore, by abstraction.
_On the contrary,_ The Philosopher says (De Anima iii, 4) that "things
are intelligible in proportion as they are separate from matter."
Therefore material things must needs be understood according as they
are abstracted from matter and from material images, namely,
phantasms.
_I answer that,_ As stated above (Q. 84, A. 7), the object of
knowledge is proportionate to the power of knowledge. Now there are
three grades of the cognitive powers. For one cognitive power,
namely, the sense, is the act of a corporeal organ. And therefore the
object of every sensitive power is a form as existing in corporeal
matter. And since such matter is the principle of individuality,
therefore every power of the sensitive part can only have knowledge
of the individual. There is another grade of cognitive power which is
neither the act of a corporeal organ, nor in any way connected with
corporeal matter; such is the angelic intellect, the object of whose
cognitive power is therefore a form existing apart from matter: for
though angels know material things, yet they do not know them save in
something immaterial, namely, either in themselves or in God. But the
human intellect holds a middle place: for it is not the act of an
organ; yet it is a power of the soul which is the form of the body,
as is clear from what we have said above (Q. 76, A. 1). And therefore
it is proper to it to know a form existing individually in corporeal
matter, but not as existing in this individual matter. But to know
what is in individual matter, not as existing in such matter, is to
abstract the form from individual matter which is represented by the
phantasms. Therefore we must needs say that our intellect understands
material things by abstracting from the phantasms; and through
material things thus considered we acquire some knowledge of
immaterial things, just as, on the contrary, angels know material
things through the immaterial.
But Plato, considering only the immateriality of the human intellect,
and not its being in a way united to the body, held that the objects
of the intellect are separate ideas; and that we understand not by
abstraction, but by participating things abstract, as stated above
(Q. 84, A. 1).
Reply Obj. 1: Abstraction may occur in two ways: First, by way of
composition and division; thus we may understand that one thing does
not exist in some other, or that it is separate therefrom. Secondly,
by way of simple and absolute consideration; thus we understand one
thing without considering the other. Thus for the intellect to
abstract one from another things which are not really abstract from
one another, does, in the first mode of abstraction, imply falsehood.
But, in the second mode of abstraction, for the intellect to abstract
things which are not really abstract from one another, does not
involve falsehood, as clearly appears in the case of the senses. For
if we understood or said that color is not in a colored body, or that
it is separate from it, there would be error in this opinion or
assertion. But if we consider color and its properties, without
reference to the apple which is colored; or if we express in word
what we thus understand, there is no error in such an opinion or
assertion, because an apple is not essential to color, and therefore
color can be understood independently of the apple. Likewise, the
things which belong to the species of a material thing, such as a
stone, or a man, or a horse, can be thought of apart from the
individualizing principles which do not belong to the notion of the
species. This is what we mean by abstracting the universal from the
particular, or the intelligible species from the phantasm; that is,
by considering the nature of the species apart from its individual
qualities represented by the phantasms. If, therefore, the intellect
is said to be false when it understands a thing otherwise than as it
is, that is so, if the word "otherwise" refers to the thing
understood; for the intellect is false when it understands a thing
otherwise than as it is; and so the intellect would be false if it
abstracted the species of a stone from its matter in such a way as to
regard the species as not existing in matter, as Plato held. But it
is not so, if the word "otherwise" be taken as referring to the one
who understands. For it is quite true that the mode of understanding,
in one who understands, is not the same as the mode of a thing in
existing: since the thing understood is immaterially in the one who
understands, according to the mode of the intellect, and not
materially, according to the mode of a material thing.
Reply Obj. 2: Some have thought that the species of a natural thing
is a form only, and that matter is not part of the species. If that
were so, matter would not enter into the definition of natural
things. Therefore it must be said otherwise, that matter is twofold,
common, and "signate" or individual; common, such as flesh and bone;
and individual, as this flesh and these bones. The intellect
therefore abstracts the species of a natural thing from the
individual sensible matter, but not from the common sensible matter;
for example, it abstracts the species of man from "this flesh and
these bones," which do not belong to the species as such, but to the
individual (Metaph. vii, Did. vi, 10), and need not be considered in
the species: whereas the species of man cannot be abstracted by the
intellect from "flesh and bones."
Mathematical species, however, can be abstracted by the intellect
from sensible matter, not only from individual, but also from common
matter; not from common intelligible matter, but only from individual
matter. For sensible matter is corporeal matter as subject to
sensible qualities, such as being cold or hot, hard or soft, and the
like: while intelligible matter is substance as subject to quantity.
Now it is manifest that quantity is in substance before other
sensible qualities are. Hence quantities, such as number, dimension,
and figures, which are the terminations of quantity, can be
considered apart from sensible qualities; and this is to abstract
them from sensible matter; but they cannot be considered without
understanding the substance which is subject to the quantity; for
that would be to abstract them from common intelligible matter. Yet
they can be considered apart from this or that substance; for that is
to abstract them from individual intelligible matter. But some things
can be abstracted even from common intelligible matter, such as
"being," "unity," "power," "act," and the like; all these can exist
without matter, as is plain regarding immaterial things. Because
Plato failed to consider the twofold kind of abstraction, as above
explained (ad 1), he held that all those things which we have stated
to be abstracted by the intellect, are abstract in reality.
Reply Obj. 3: Colors, as being in individual corporeal matter, have
the same mode of existence as the power of sight: therefore they can
impress their own image on the eye. But phantasms, since they are
images of individuals, and exist in corporeal organs, have not the
same mode of existence as the human intellect, and therefore have
not the power of themselves to make an impression on the passive
intellect. This is done by the power of the active intellect which
by turning towards the phantasm produces in the passive intellect a
certain likeness which represents, as to its specific conditions
only, the thing reflected in the phantasm. It is thus that the
intelligible species is said to be abstracted from the phantasm;
not that the identical form which previously was in the phantasm is
subsequently in the passive intellect, as a body transferred from
one place to another.
Reply Obj. 4: Not only does the active intellect throw light on
the phantasm: it does more; by its own power it abstracts the
intelligible species from the phantasm. It throws light on the
phantasm, because, just as the sensitive part acquires a greater
power by its conjunction with the intellectual part, so by the power
of the active intellect the phantasms are made more fit for the
abstraction therefrom of intelligible intentions. Furthermore, the
active intellect abstracts the intelligible species from the
phantasm, forasmuch as by the power of the active intellect we are
able to disregard the conditions of individuality, and to take into
our consideration the specific nature, the image of which informs
the passive intellect.
Reply Obj. 5: Our intellect both abstracts the intelligible species
from the phantasms, inasmuch as it considers the natures of things
in universal, and, nevertheless, understands these natures in the
phantasms since it cannot understand even the things of which it
abstracts the species, without turning to the phantasms, as we have
said above (Q. 84, A. 7).
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