Therefore
the intellect understands many things at the same time.
Summa Theologica
Under this
head there are eight points of inquiry:
(1) Whether our intellect understands by abstracting the species from
the phantasms?
(2) Whether the intelligible species abstracted from the phantasms are
what our intellect understands, or that whereby it understands?
(3) Whether our intellect naturally first understands the more
universal?
(4) Whether our intellect can know many things at the same time?
(5) Whether our intellect understands by the process of composition and
division?
(6) Whether the intellect can err?
(7) Whether one intellect can understand better than another?
(8) Whether our intellect understands the indivisible before the
divisible?
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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.
Objection 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.
Objection 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.
Objection 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.
Objection 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 ([683]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 the body, as is clear from
what we have said above ([684]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
([685]Q[84] , A[1]).
Reply to Objection 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 to Objection 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 form "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 to Objection 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 to Objection 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 to Objection 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 ([686]Q[84], A[7]).
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Whether the intelligible species abstracted from the phantasm is related to
our intellect as that which is understood?
Objection 1: It would seem that the intelligible species abstracted
from the phantasm is related to our intellect as that which is
understood. For the understood in act is in the one who understands:
since the understood in act is the intellect itself in act. But nothing
of what is understood is in the intellect actually understanding, save
the abstracted intelligible species. Therefore this species is what is
actually understood.
Objection 2: Further, what is actually understood must be in something;
else it would be nothing. But it is not in something outside the soul:
for, since what is outside the soul is material, nothing therein can be
actually understood. Therefore what is actually understood is in the
intellect. Consequently it can be nothing else than the aforesaid
intelligible species.
Objection 3: Further, the Philosopher says (1 Peri Herm. i) that "words
are signs of the passions in the soul. " But words signify the things
understood, for we express by word what we understand. Therefore these
passions of the soul---viz. the intelligible species, are what is
actually understood.
On the contrary, The intelligible species is to the intellect what the
sensible image is to the sense. But the sensible image is not what is
perceived, but rather that by which sense perceives. Therefore the
intelligible species is not what is actually understood, but that by
which the intellect understands.
I answer that, Some have asserted that our intellectual faculties know
only the impression made on them; as, for example, that sense is
cognizant only of the impression made on its own organ. According to
this theory, the intellect understands only its own impression, namely,
the intelligible species which it has received, so that this species is
what is understood.
This is, however, manifestly false for two reasons. First, because the
things we understand are the objects of science; therefore if what we
understand is merely the intelligible species in the soul, it would
follow that every science would not be concerned with objects outside
the soul, but only with the intelligible species within the soul; thus,
according to the teaching of the Platonists all science is about ideas,
which they held to be actually understood [*[687]Q[84], A[1]].
Secondly, it is untrue, because it would lead to the opinion of the
ancients who maintained that "whatever seems, is true" [*Aristotle,
Metaph. iii. 5], and that consequently contradictories are true
simultaneously. For if the faculty knows its own impression only, it
can judge of that only. Now a thing seems according to the impression
made on the cognitive faculty. Consequently the cognitive faculty will
always judge of its own impression as such; and so every judgment will
be true: for instance, if taste perceived only its own impression, when
anyone with a healthy taste perceives that honey is sweet, he would
judge truly; and if anyone with a corrupt taste perceives that honey is
bitter, this would be equally true; for each would judge according to
the impression on his taste. Thus every opinion would be equally true;
in fact, every sort of apprehension.
Therefore it must be said that the intelligible species is related to
the intellect as that by which it understands: which is proved thus.
There is a twofold action (Metaph. ix, Did. viii, 8), one which remains
in the agent; for instance, to see and to understand; and another which
passes into an external object; for instance, to heat and to cut; and
each of these actions proceeds in virtue of some form. And as the form
from which proceeds an act tending to something external is the
likeness of the object of the action, as heat in the heater is a
likeness of the thing heated; so the form from which proceeds an action
remaining in the agent is the likeness of the object. Hence that by
which the sight sees is the likeness of the visible thing; and the
likeness of the thing understood, that is, the intelligible species, is
the form by which the intellect understands. But since the intellect
reflects upon itself, by such reflection it understands both its own
act of intelligence, and the species by which it understands. Thus the
intelligible species is that which is understood secondarily; but that
which is primarily understood is the object, of which the species is
the likeness. This also appears from the opinion of the ancient
philosophers, who said that "like is known by like. " For they said that
the soul knows the earth outside itself, by the earth within itself;
and so of the rest. If, therefore, we take the species of the earth
instead of the earth, according to Aristotle (De Anima iii, 8), who
says "that a stone is not in the soul, but only the likeness of the
stone"; it follows that the soul knows external things by means of its
intelligible species.
Reply to Objection 1: The thing understood is in the intellect by its
own likeness; and it is in this sense that we say that the thing
actually understood is the intellect in act, because the likeness of
the thing understood is the form of the intellect, as the likeness of a
sensible thing is the form of the sense in act. Hence it does not
follow that the intelligible species abstracted is what is actually
understood; but rather that it is the likeness thereof.
Reply to Objection 2: In these words "the thing actually understood"
there is a double implication---the thing which is understood, and the
fact that it is understood. In like manner the words "abstract
universal" imply two things, the nature of a thing and its abstraction
or universality. Therefore the nature itself to which it occurs to be
understood, abstracted or considered as universal is only in
individuals; but that it is understood, abstracted or considered as
universal is in the intellect. We see something similar to this is in
the senses. For the sight sees the color of the apple apart from its
smell. If therefore it be asked where is the color which is seen apart
from the smell, it is quite clear that the color which is seen is only
in the apple: but that it be perceived apart from the smell, this is
owing to the sight, forasmuch as the faculty of sight receives the
likeness of color and not of smell. In like manner humanity understood
is only in this or that man; but that humanity be apprehended without
conditions of individuality, that is, that it be abstracted and
consequently considered as universal, occurs to humanity inasmuch as it
is brought under the consideration of the intellect, in which there is
a likeness of the specific nature, but not of the principles of
individuality.
Reply to Objection 3: There are two operations in the sensitive part.
One, in regard of impression only, and thus the operation of the senses
takes place by the senses being impressed by the sensible. The other is
formation, inasmuch as the imagination forms for itself an image of an
absent thing, or even of something never seen. Both of these operations
are found in the intellect. For in the first place there is the passion
of the passive intellect as informed by the intelligible species; and
then the passive intellect thus informed forms a definition, or a
division, or a composition, expressed by a word. Wherefore the concept
conveyed by a word is its definition; and a proposition conveys the
intellect's division or composition. Words do not therefore signify the
intelligible species themselves; but that which the intellect forms for
itself for the purpose of judging of external things.
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Whether the more universal is first in our intellectual cognition?
Objection 1: It would seem that the more universal is not first in our
intellectual cognition. For what is first and more known in its own
nature, is secondarily and less known in relation to ourselves. But
universals come first as regards their nature, because "that is first
which does not involve the existence of its correlative" (Categor. ix).
Therefore the universals are secondarily known as regards our
intellect.
Objection 2: Further, the composition precedes the simple in relation
to us. But universals are the more simple. Therefore they are known
secondarily by us.
Objection 3: Further, the Philosopher says (Phys. i, 1), that the
object defined comes in our knowledge before the parts of its
definition. But the more universal is part of the definition of the
less universal, as "animal" is part of the definition of "man. "
Therefore the universals are secondarily known by us.
Objection 4: Further, we know causes and principles by their effects.
But universals are principles. Therefore universals are secondarily
known by us.
On the contrary, "We must proceed from the universal to the singular
and individual" (Phys. i, 1)
I answer that, In our knowledge there are two things to be considered.
First, that intellectual knowledge in some degree arises from sensible
knowledge: and, because sense has singular and individual things for
its object, and intellect has the universal for its object, it follows
that our knowledge of the former comes before our knowledge of the
latter. Secondly, we must consider that our intellect proceeds from a
state of potentiality to a state of actuality; and every power thus
proceeding from potentiality to actuality comes first to an incomplete
act, which is the medium between potentiality and actuality, before
accomplishing the perfect act. The perfect act of the intellect is
complete knowledge, when the object is distinctly and determinately
known; whereas the incomplete act is imperfect knowledge, when the
object is known indistinctly, and as it were confusedly. A thing thus
imperfectly known, is known partly in act and partly in potentiality,
and hence the Philosopher says (Phys. i, 1), that "what is manifest and
certain is known to us at first confusedly; afterwards we know it by
distinguishing its principles and elements. " Now it is evident that to
know an object that comprises many things, without proper knowledge of
each thing contained in it, is to know that thing confusedly. In this
way we can have knowledge not only of the universal whole, which
contains parts potentially, but also of the integral whole; for each
whole can be known confusedly, without its parts being known. But to
know distinctly what is contained in the universal whole is to know the
less common, as to "animal" indistinctly is to know it as "animal";
whereas to know "animal" distinctly is know it as "rational" or
"irrational animal," that is, to know a man or a lion: therefore our
intellect knows "animal" before it knows man; and the same reason holds
in comparing any more universal idea with the less universal.
Moreover, as sense, like the intellect, proceeds from potentiality to
act, the same order of knowledge appears in the senses. For by sense we
judge of the more common before the less common, in reference both to
place and time; in reference to place, when a thing is seen afar off it
is seen to be a body before it is seen to be an animal; and to be an
animal before it is seen to be a man, and to be a man before it seen to
be Socrates or Plato; and the same is true as regards time, for a child
can distinguish man from not man before he distinguishes this man from
that, and therefore "children at first call men fathers, and later on
distinguish each one from the others" (Phys. i, 1). The reason of this
is clear: because he who knows a thing indistinctly is in a state of
potentiality as regards its principle of distinction; as he who knows
"genus" is in a state of potentiality as regards "difference. " Thus it
is evident that indistinct knowledge is midway between potentiality and
act.
We must therefore conclude that knowledge of the singular and
individual is prior, as regards us, to the knowledge of the universal;
as sensible knowledge is prior to intellectual knowledge. But in both
sense and intellect the knowledge of the more common precedes the
knowledge of the less common.
Reply to Objection 1: The universal can be considered in two ways.
First, the universal nature may be considered together with the
intention of universality. And since the intention of
universality---viz. the relation of one and the same to many---is due
to intellectual abstraction, the universal thus considered is a
secondary consideration. Hence it is said (De Anima i, 1) that the
"universal animal is either nothing or something secondary. " But
according to Plato, who held that universals are subsistent, the
universal considered thus would be prior to the particular, for the
latter, according to him, are mere participations of the subsistent
universals which he called ideas.
Secondly, the universal can be considered in the nature itself---for
instance, animality or humanity as existing in the individual. And thus
we must distinguish two orders of nature: one, by way of generation and
time; and thus the imperfect and the potential come first. In this way
the more common comes first in the order of nature; as appears clearly
in the generation of man and animal; for "the animal is generated
before man," as the Philosopher says (De Gener. Animal ii, 3). The
other order is the order of perfection or of the intention of nature:
for instance, act considered absolutely is naturally prior to
potentiality, and the perfect to the imperfect: thus the less common
comes naturally before the more common; as man comes before animal. For
the intention of nature does not stop at the generation of animal but
goes on to the generation of man.
Reply to Objection 2: The more common universal may be compared to the
less common, as the whole, and as the part. As the whole, considering
that in the more universal is potentially contained not only the less
universal, but also other things, as in "animal" is contained not only
"man" but also "horse. " As part, considering that the less common
contains in its idea not only the more common, but also more; as "man"
contains not only "animal" but also "rational. " Therefore "animal" in
itself comes into our knowledge before "man"; but "man" comes before
"animal" considered as part of the same idea.
Reply to Objection 3: A part can be known in two ways. First,
absolutely considered in itself; and thus nothing prevents the parts
being known before the whole, as stones are known before a house is
known. Secondly as belonging to a certain whole; and thus we must needs
know the whole before its parts. For we know a house vaguely before we
know its different parts. So likewise principles of definition are
known before the thing defined is known; otherwise the thing defined
would not be known at all. But as parts of the definition they are
known after. For we know man vaguely as man before we know how to
distinguish all that belongs to human nature.
Reply to Objection 4: The universal, as understood with the intention
of universality, is, indeed, in a way, a principle of knowledge, in so
far as the intention of universality results from the mode of
understanding by way of abstraction. But what is a principle of
knowledge is not of necessity a principle of existence, as Plato
thought: since at times we know a cause through its effect, and
substance through accidents. Wherefore the universal thus considered,
according to the opinion of Aristotle, is neither a principle of
existence, nor a substance, as he makes clear (Metaph. vii, Did. vi,
13). But if we consider the generic or specific nature itself as
existing in the singular, thus in a way it is in the nature of a formal
principle in regard to the singulars: for the singular is the result of
matter, while the idea of species is from the form. But the generic
nature is compared to the specific nature rather after the fashion of a
material principle, because the generic nature is taken from that which
is material in a thing, while the idea of species is taken from that
which is formal: thus the notion of animal is taken from the sensitive
part, whereas the notion of man is taken from the intellectual part.
Thus it is that the ultimate intention of nature is to the species and
not to the individual, or the genus: because the form is the end of
generation, while matter is for the sake of the form. Neither is it
necessary that, as regards us, knowledge of any cause or principle
should be secondary: since at times through sensible causes we become
acquainted with unknown effects, and sometimes conversely.
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Whether we can understand many things at the same time?
Objection 1: It would seem that we can understand many things at the
same time. For intellect is above time, whereas the succession of
before and after belongs to time. Therefore the intellect does not
understand different things in succession, but at the same time.
Objection 2: Further, there is nothing to prevent different forms not
opposed to each other from actually being in the same subject, as, for
instance, color and smell are in the apple. But intelligible species
are not opposed to each other. Therefore there is nothing to prevent
the same intellect being in act as regards different intelligible
species, and thus it can understand many things at the same time.
Objection 3: Further, the intellect understands a whole at the same
time, such as a man or a house. But a whole contains many parts.
Therefore the intellect understands many things at the same time.
Objection 4: Further, we cannot know the difference between two things
unless we know both at the same time (De Anima iii, 2), and the same is
to be said of any other comparison. But our intellect knows the
difference and comparison between one thing and another. Therefore it
knows many things at the same time.
On the contrary, It is said (Topic. ii, 10) that "understanding is of
one thing only, knowledge is of many. "
I answer that, The intellect can, indeed, understand many things as
one, but not as many: that is to say by "one" but not by "many"
intelligible species. For the mode of every action follows the form
which is the principle of that action. Therefore whatever things the
intellect can understand under one species, it can understand at the
same time: hence it is that God sees all things at the same time,
because He sees all in one, that is, in His Essence. But whatever
things the intellect understands under different species, it does not
understand at the same time. The reason of this is that it is
impossible for one and the same subject to be perfected at the same
time by many forms of one genus and diverse species, just as it is
impossible for one and the same body at the same time to have different
colors or different shapes. Now all intelligible species belong to one
genus, because they are the perfections of one intellectual faculty:
although the things which the species represent belong to different
genera. Therefore it is impossible for one and the same intellect to be
perfected at the same time by different intelligible species so as
actually to understand different things.
Reply to Objection 1: The intellect is above that time, which is the
measure of the movement of corporeal things. But the multitude itself
of intelligible species causes a certain vicissitude of intelligible
operations, according as one operation succeeds another. And this
vicissitude is called time by Augustine, who says (Gen. ad lit. viii,
20,22), that "God moves the spiritual creature through time. "
Reply to Objection 2: Not only is it impossible for opposite forms to
exist at the same time in the same subject, but neither can any forms
belonging to the same genus, although they be not opposed to one
another, as is clear from the examples of colors and shapes.
Reply to Objection 3: Parts can be understood in two ways. First, in a
confused way, as existing in the whole, and thus they are known through
the one form of the whole, and so are known together. In another way
they are known distinctly: thus each is known by its species; and so
they are not understood at the same time.
Reply to Objection 4: If the intellect sees the difference or
comparison between one thing and another, it knows both in relation to
their difference or comparison; just, as we have said above (ad 3), as
it knows the parts in the whole.
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Whether our intellect understands by composition and division?
Objection 1: It would seem that our intellect does not understand by
composition and division. For composition and division are only of
many; whereas the intellect cannot understand many things at the same
time. Therefore it cannot understand by composition and division.
Objection 2: Further, every composition and division implies past,
present, or future time. But the intellect abstracts from time, as also
from other individual conditions. Therefore the intellect does not
understand by composition and division.
Objection 3: Further, the intellect understands things by a process of
assimilation to them. But composition and division are not in things,
for nothing is in things but what is signified by the predicate and the
subject, and which is one and the same, provided that the composition
be true, for "man" is truly what "animal" is. Therefore the intellect
does not act by composition and division.
On the contrary, Words signify the conceptions of the intellect, as the
Philosopher says (Peri Herm. i). But in words we find composition and
division, as appears in affirmative and negative propositions.
Therefore the intellect acts by composition and division.
I answer that, The human intellect must of necessity understand by
composition and division. For since the intellect passes from
potentiality to act, it has a likeness to things which are generated,
which do not attain to perfection all at once but acquire it by
degrees: so likewise the human intellect does not acquire perfect
knowledge by the first act of apprehension; but it first apprehends
something about its object, such as its quiddity, and this is its first
and proper object; and then it understands the properties, accidents,
and the various relations of the essence. Thus it necessarily compares
one thing with another by composition or division; and from one
composition and division it proceeds to another, which is the process
of reasoning.
But the angelic and the Divine intellect, like all incorruptible
things, have their perfection at once from the beginning. Hence the
angelic and the Divine intellect have the entire knowledge of a thing
at once and perfectly; and hence also in knowing the quiddity of a
thing they know at once whatever we can know by composition, division,
and reasoning. Therefore the human intellect knows by composition,
division and reasoning. But the Divine intellect and the angelic
intellect know, indeed, composition, division, and reasoning, not by
the process itself, but by understanding the simple essence.
Reply to Objection 1: Composition and division of the intellect are
made by differentiating and comparing. Hence the intellect knows many
things by composition and division, as by knowing the difference and
comparison of things.
Reply to Objection 2: Although the intellect abstracts from the
phantasms, it does not understand actually without turning to the
phantasms, as we have said [688](A[1]; [689]Q[84], A[7]). And forasmuch
as it turns to the phantasms, composition and division of the intellect
involve time.
Reply to Objection 3: The likeness of a thing is received into the
intellect according to the mode of the intellect, not according to the
mode of the thing. Wherefore something on the part of the thing
corresponds to the composition and division of the intellect; but it
does not exist in the same way in the intellect and in the thing. For
the proper object of the human intellect is the quiddity of a material
thing, which comes under the action of the senses and the imagination.
Now in a material thing there is a twofold composition. First, there is
the composition of form with matter; and to this corresponds that
composition of the intellect whereby the universal whole is predicated
of its part: for the genus is derived from common matter, while the
difference that completes the species is derived from the form, and the
particular from individual matter. The second comparison is of accident
with subject: and to this real composition corresponds that composition
of the intellect, whereby accident is predicated of subject, as when we
say "the man is white. " Nevertheless composition of the intellect
differs from composition of things; for in the latter the things are
diverse, whereas composition of the intellect is a sign of the identity
of the components. For the above composition of the intellect does not
imply that "man" and "whiteness" are identical, but the assertion, "the
man is white," means that "the man is something having whiteness": and
the subject, which is a man, is identified with a subject having
whiteness. It is the same with the composition of form and matter: for
animal signifies that which has a sensitive nature; rational, that
which has an intellectual nature; man, that which has both; and
Socrates that which has all these things together with individual
matter; and according to this kind of identity our intellect predicates
the composition of one thing with another.
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Whether the intellect can be false?
Objection 1: It would seem that the intellect can be false; for the
Philosopher says (Metaph. vi, Did. v, 4) that "truth and falsehood are
in the mind. " But the mind and intellect are the same, as is shown
above ([690]Q[79], A[1]). Therefore falsehood may be in the mind.
Objection 2: Further, opinion and reasoning belong to the intellect.
But falsehood exists in both. Therefore falsehood can be in the
intellect.
Objection 3: Further, sin is in the intellectual faculty. But sin
involves falsehood: for "those err that work evil" (Prov. 14:22).
Therefore falsehood can be in the intellect.
On the contrary, Augustine says (QQ. 83, qu. 32), that "everyone who is
deceived, does not rightly understand that wherein he is deceived. " And
the Philosopher says (De Anima iii, 10), that "the intellect is always
true. "
I answer that, The Philosopher (De Anima iii, 6) compares intellect
with sense on this point. For sense is not deceived in its proper
object, as sight in regard to color; has accidentally through some
hindrance occurring to the sensile organ---for example, the taste of a
fever-stricken person judges a sweet thing to be bitter, through his
tongue being vitiated by ill humors. Sense, however, may be deceived as
regards common sensible objects, as size or figure; when, for example,
it judges the sun to be only a foot in diameter, whereas in reality it
exceeds the earth in size. Much more is sense deceived concerning
accidental sensible objects, as when it judges that vinegar is honey by
reason of the color being the same. The reason of this is evident; for
every faculty, as such, is "per se" directed to its proper object; and
things of this kind are always the same. Hence, as long as the faculty
exists, its judgment concerning its own proper object does not fail.
Now the proper object of the intellect is the "quiddity" of a material
thing; and hence, properly speaking, the intellect is not at fault
concerning this quiddity; whereas it may go astray as regards the
surroundings of the thing in its essence or quiddity, in referring one
thing to another, as regards composition or division, or also in the
process of reasoning. Therefore, also in regard to those propositions,
which are understood, the intellect cannot err, as in the case of first
principles from which arises infallible truth in the certitude of
scientific conclusions.
The intellect, however, may be accidentally deceived in the quiddity of
composite things, not by the defect of its organ, for the intellect is
a faculty that is independent of an organ; but on the part of the
composition affecting the definition, when, for instance, the
definition of a thing is false in relation to something else, as the
definition of a circle applied to a triangle; or when a definition is
false in itself as involving the composition of things incompatible;
as, for instance, to describe anything as "a rational winged animal. "
Hence as regards simple objects not subject to composite definitions we
cannot be deceived unless, indeed, we understand nothing whatever about
them, as is said Metaph. ix, Did. viii, 10.
Reply to Objection 1: The Philosopher says that falsehood is in the
intellect in regard to composition and division. The same answer
applies to the Second Objection concerning opinion and reasoning, and
to the Third Objection, concerning the error of the sinner, who errs in
the practical judgment of the appetible object. But in the absolute
consideration of the quiddity of a thing, and of those things which are
known thereby, the intellect is never deceived. In this sense are to be
understood the authorities quoted in proof of the opposite conclusion.
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Whether one person can understand one and the same thing better than another
can?
Objection 1: It would seem that one person cannot understand one and
the same thing better than another can. For Augustine says (QQ. 83, qu.
32), "Whoever understands a thing otherwise than as it is, does not
understand it at all. Hence it is clear that there is a perfect
understanding, than which none other is more perfect: and therefore
there are not infinite degrees of understanding a thing: nor can one
person understand a thing better than another can. "
Objection 2: Further, the intellect is true in its act of
understanding. But truth, being a certain equality between thought and
thing, is not subject to more or less; for a thing cannot be said to be
more or less equal. Therefore a thing cannot be more or less
understood.
Objection 3: Further, the intellect is the most formal of all that is
in man. But different forms cause different species. Therefore if one
man understands better than another, it would seem that they do not
belong to the same species.
On the contrary, Experience shows that some understand more profoundly
than do others; as one who carries a conclusion to its first principles
and ultimate causes understands it better than the one who reduces it
only to its proximate causes.
I answer that, A thing being understood more by one than by another may
be taken in two senses. First, so that the word "more" be taken as
determining the act of understanding as regards the thing understood;
and thus, one cannot understand the same thing more than another,
because to understand it otherwise than as it is, either better or
worse, would entail being deceived, and such a one would not understand
it, as Augustine argues (QQ. 83, qu. 32). In another sense the word
"more" can be taken as determining the act of understanding on the part
of him who understands; and so one may understand the same thing better
than someone else, through having a greater power of understanding:
just as a man may see a thing better with his bodily sight, whose power
is greater, and whose sight is more perfect. The same applies to the
intellect in two ways. First, as regards the intellect itself, which is
more perfect. For it is plain that the better the disposition of a
body, the better the soul allotted to it; which clearly appears in
things of different species: and the reason thereof is that act and
form are received into matter according to matter's capacity: thus
because some men have bodies of better disposition, their souls have a
greater power of understanding, wherefore it is said (De Anima ii, 9),
that "it is to be observed that those who have soft flesh are of apt
mind. " Secondly, this occurs in regard to the lower powers of which the
intellect has need in its operation: for those in whom the imaginative,
cogitative, and memorative powers are of better disposition, are better
disposed to understand.
The reply to the First Objection is clear from the above; likewise the
reply to the Second, for the truth of the intellect consists in the
intellect understanding a thing as it is.
Reply to Objection 3: The difference of form which is due only to the
different disposition of matter, causes not a specific but only a
numerical difference: for different individuals have different forms,
diversified according to the difference of matter.
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Whether the intellect understands the indivisible before the divisible?
Objection 1: It would seem that the intellect understands the
indivisible before the divisible. For the Philosopher says (Phys. i, 1)
that "we understand and know from the knowledge of principles and
elements. " But principles are indivisible, and elements are of
divisible things. Therefore the indivisible is known to us before the
divisible.
Objection 2: Further, the definition of a thing contains what is known
previously, for a definition "proceeds from the first and more known,"
as is said Topic. vi, 4. But the indivisible is part of the definition
of the divisible; as a point comes into the definition of a line; for
as Euclid says, "a line is length without breadth, the extremities of
which are points"; also unity comes into the definition of number, for
"number is multitude measured by one," as is said Metaph. x, Did. ix,
6. Therefore our intellect understands the indivisible before the
divisible.
Objection 3: Further, "Like is known by like. " But the indivisible is
more like to the intellect than is the divisible; because "the
intellect is simple" (De Anima iii, 4). Therefore our intellect first
knows the indivisible.
On the contrary, It is said (De Anima iii, 6) that "the indivisible is
expressed as a privation. " But privation is known secondarily.
Therefore likewise is the indivisible.
I answer that, The object of our intellect in its present state is the
quiddity of a material thing, which it abstracts from the phantasms, as
above stated ([691]Q[84], A[7]). And since that which is known first
and of itself by our cognitive power is its proper object, we must
consider its relationship to that quiddity in order to discover in what
order the indivisible is known. Now the indivisible is threefold, as is
said De Anima iii, 6. First, the continuous is indivisible, since
actually it is undivided, although potentially divisible: and this
indivisible is known to us before its division, which is a division
into parts: because confused knowledge is prior to distinct knowledge,
as we have said above [692](A[3]). Secondly, the indivisible is so
called in relation to species, as man's reason is something
indivisible. This way, also, the indivisible is understood before its
division into logical parts, as we have said above (De Anima iii, 6);
and again before the intellect disposes and divides by affirmation and
negation. The reason of this is that both these kinds of indivisible
are understood by the intellect of itself, as being its proper object.
The third kind of indivisible is what is altogether indivisible, as a
point and unity, which cannot be divided either actually or
potentially. And this indivisible is known secondarily, through the
privation of divisibility. Wherefore a point is defined by way of
privation "as that which has no parts"; and in like manner the notion
of "one" is that is "indivisible," as stated in Metaph. x, Did. ix, 1.
And the reason of this is that this indivisible has a certain
opposition to a corporeal being, the quiddity of which is the primary
and proper object of the intellect.
But if our intellect understood by participation of certain separate
indivisible (forms), as the Platonists maintained, it would follow that
a like indivisible is understood primarily; for according to the
Platonists what is first is first participated by things.
Reply to Objection 1: In the acquisition of knowledge, principles and
elements are not always (known) first: for sometimes from sensible
effects we arrive at the knowledge of principles and intelligible
causes. But in perfect knowledge, the knowledge of effects always
depends on the knowledge of principles and elements: for as the
Philosopher says in the same passage: "Then do we consider that we
know, when we can resolve principles into their causes. "
Reply to Objection 2: A point is not included in the definition of a
line in general: for it is manifest that in a line of indefinite
length, and in a circular line, there is no point, save potentially.
Euclid defines a finite straight line: and therefore he mentions a
point in the definition, as the limit in the definition of that which
is limited. Unity is the measure of number: wherefore it is included in
the definition of a measured number. But it is not included in the
definition of the divisible, but rather conversely.
Reply to Objection 3: The likeness through which we understand is the
species of the known in the knower; therefore a thing is known first,
not on account of its natural likeness to the cognitive power, but on
account of the power's aptitude for the object: otherwise sight would
perceive hearing rather than color.
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WHAT OUR INTELLECT KNOWS IN MATERIAL THINGS (FOUR ARTICLES)
We now have to consider what our intellect knows in material things.
Under this head there are four points of inquiry:
(1) Whether it knows singulars?
(2) Whether it knows the infinite?
(3) Whether it knows contingent things?
(4) Whether it knows future things?
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Whether our intellect knows singulars?
Objection 1: It would seem that our intellect knows singulars. For
whoever knows composition, knows the terms of composition. But our
intellect knows this composition; "Socrates is a man": for it belongs
to the intellect to form a proposition. Therefore our intellect knows
this singular, Socrates.
Objection 2: Further, the practical intellect directs to action. But
action has relation to singular things. Therefore the intellect knows
the singular.
Objection 3: Further, our intellect understands itself. But in itself
it is a singular, otherwise it would have no action of its own; for
actions belong to singulars. Therefore our intellect knows singulars.
Objection 4: Further, a superior power can do whatever is done by an
inferior power. But sense knows the singular. Much more, therefore, can
the intellect know it.
On the contrary, The Philosopher says (Phys. i, 5), that "the universal
is known by reason; and the singular is known by sense. "
I answer that, Our intellect cannot know the singular in material
things directly and primarily. The reason of this is that the principle
of singularity in material things is individual matter, whereas our
intellect, as have said above ([693]Q[85], A[1]), understands by
abstracting the intelligible species from such matter. Now what is
abstracted from individual matter is the universal. Hence our intellect
knows directly the universal only. But indirectly, and as it were by a
kind of reflection, it can know the singular, because, as we have said
above ([694]Q[85], A[7]), even after abstracting the intelligible
species, the intellect, in order to understand, needs to turn to the
phantasms in which it understands the species, as is said De Anima iii,
7. Therefore it understands the universal directly through the
intelligible species, and indirectly the singular represented by the
phantasm. And thus it forms the proposition "Socrates is a man. "
Wherefore the reply to the first objection is clear.
Reply to Objection 2: The choice of a particular thing to be done is as
the conclusion of a syllogism formed by the practical intellect, as is
said Ethic. vii, 3. But a singular proposition cannot be directly
concluded from a universal proposition, except through the medium of a
singular proposition. Therefore the universal principle of the
practical intellect does not move save through the medium of the
particular apprehension of the sensitive part, as is said De Anima iii,
11.
Reply to Objection 3: Intelligibility is incompatible with the singular
not as such, but as material, for nothing can be understood otherwise
than immaterially. Therefore if there be an immaterial singular such as
the intellect, there is no reason why it should not be intelligible.
Reply to Objection 4: The higher power can do what the lower power can,
but in a more eminent way. Wherefore what the sense knows materially
and concretely, which is to know the singular directly, the intellect
knows immaterially and in the abstract, which is to know the universal.
__________________________________________________________________
Whether our intellect can know the infinite?
Objection 1: It would seem that our intellect can know the infinite.
For God excels all infinite things. But our intellect can know God, as
we have said above ([695]Q[12], A[1]). Much more, therefore, can our
intellect know all other infinite things.
Objection 2: Further, our intellect can naturally know "genera" and
"species. " But there is an infinity of species in some genera, as in
number, proportion, and figure. Therefore our intellect can know the
infinite.
Objection 3: Further, if one body can coexist with another in the same
place, there is nothing to prevent an infinite number of bodies being
in one place. But one intelligible species can exist with another in
the same intellect, for many things can be habitually known at the same
time. Therefore our intellect can have an habitual knowledge of an
infinite number of things.
head there are eight points of inquiry:
(1) Whether our intellect understands by abstracting the species from
the phantasms?
(2) Whether the intelligible species abstracted from the phantasms are
what our intellect understands, or that whereby it understands?
(3) Whether our intellect naturally first understands the more
universal?
(4) Whether our intellect can know many things at the same time?
(5) Whether our intellect understands by the process of composition and
division?
(6) Whether the intellect can err?
(7) Whether one intellect can understand better than another?
(8) Whether our intellect understands the indivisible before the
divisible?
__________________________________________________________________
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.
Objection 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.
Objection 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.
Objection 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.
Objection 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 ([683]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 the body, as is clear from
what we have said above ([684]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
([685]Q[84] , A[1]).
Reply to Objection 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 to Objection 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 form "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 to Objection 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 to Objection 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 to Objection 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 ([686]Q[84], A[7]).
__________________________________________________________________
Whether the intelligible species abstracted from the phantasm is related to
our intellect as that which is understood?
Objection 1: It would seem that the intelligible species abstracted
from the phantasm is related to our intellect as that which is
understood. For the understood in act is in the one who understands:
since the understood in act is the intellect itself in act. But nothing
of what is understood is in the intellect actually understanding, save
the abstracted intelligible species. Therefore this species is what is
actually understood.
Objection 2: Further, what is actually understood must be in something;
else it would be nothing. But it is not in something outside the soul:
for, since what is outside the soul is material, nothing therein can be
actually understood. Therefore what is actually understood is in the
intellect. Consequently it can be nothing else than the aforesaid
intelligible species.
Objection 3: Further, the Philosopher says (1 Peri Herm. i) that "words
are signs of the passions in the soul. " But words signify the things
understood, for we express by word what we understand. Therefore these
passions of the soul---viz. the intelligible species, are what is
actually understood.
On the contrary, The intelligible species is to the intellect what the
sensible image is to the sense. But the sensible image is not what is
perceived, but rather that by which sense perceives. Therefore the
intelligible species is not what is actually understood, but that by
which the intellect understands.
I answer that, Some have asserted that our intellectual faculties know
only the impression made on them; as, for example, that sense is
cognizant only of the impression made on its own organ. According to
this theory, the intellect understands only its own impression, namely,
the intelligible species which it has received, so that this species is
what is understood.
This is, however, manifestly false for two reasons. First, because the
things we understand are the objects of science; therefore if what we
understand is merely the intelligible species in the soul, it would
follow that every science would not be concerned with objects outside
the soul, but only with the intelligible species within the soul; thus,
according to the teaching of the Platonists all science is about ideas,
which they held to be actually understood [*[687]Q[84], A[1]].
Secondly, it is untrue, because it would lead to the opinion of the
ancients who maintained that "whatever seems, is true" [*Aristotle,
Metaph. iii. 5], and that consequently contradictories are true
simultaneously. For if the faculty knows its own impression only, it
can judge of that only. Now a thing seems according to the impression
made on the cognitive faculty. Consequently the cognitive faculty will
always judge of its own impression as such; and so every judgment will
be true: for instance, if taste perceived only its own impression, when
anyone with a healthy taste perceives that honey is sweet, he would
judge truly; and if anyone with a corrupt taste perceives that honey is
bitter, this would be equally true; for each would judge according to
the impression on his taste. Thus every opinion would be equally true;
in fact, every sort of apprehension.
Therefore it must be said that the intelligible species is related to
the intellect as that by which it understands: which is proved thus.
There is a twofold action (Metaph. ix, Did. viii, 8), one which remains
in the agent; for instance, to see and to understand; and another which
passes into an external object; for instance, to heat and to cut; and
each of these actions proceeds in virtue of some form. And as the form
from which proceeds an act tending to something external is the
likeness of the object of the action, as heat in the heater is a
likeness of the thing heated; so the form from which proceeds an action
remaining in the agent is the likeness of the object. Hence that by
which the sight sees is the likeness of the visible thing; and the
likeness of the thing understood, that is, the intelligible species, is
the form by which the intellect understands. But since the intellect
reflects upon itself, by such reflection it understands both its own
act of intelligence, and the species by which it understands. Thus the
intelligible species is that which is understood secondarily; but that
which is primarily understood is the object, of which the species is
the likeness. This also appears from the opinion of the ancient
philosophers, who said that "like is known by like. " For they said that
the soul knows the earth outside itself, by the earth within itself;
and so of the rest. If, therefore, we take the species of the earth
instead of the earth, according to Aristotle (De Anima iii, 8), who
says "that a stone is not in the soul, but only the likeness of the
stone"; it follows that the soul knows external things by means of its
intelligible species.
Reply to Objection 1: The thing understood is in the intellect by its
own likeness; and it is in this sense that we say that the thing
actually understood is the intellect in act, because the likeness of
the thing understood is the form of the intellect, as the likeness of a
sensible thing is the form of the sense in act. Hence it does not
follow that the intelligible species abstracted is what is actually
understood; but rather that it is the likeness thereof.
Reply to Objection 2: In these words "the thing actually understood"
there is a double implication---the thing which is understood, and the
fact that it is understood. In like manner the words "abstract
universal" imply two things, the nature of a thing and its abstraction
or universality. Therefore the nature itself to which it occurs to be
understood, abstracted or considered as universal is only in
individuals; but that it is understood, abstracted or considered as
universal is in the intellect. We see something similar to this is in
the senses. For the sight sees the color of the apple apart from its
smell. If therefore it be asked where is the color which is seen apart
from the smell, it is quite clear that the color which is seen is only
in the apple: but that it be perceived apart from the smell, this is
owing to the sight, forasmuch as the faculty of sight receives the
likeness of color and not of smell. In like manner humanity understood
is only in this or that man; but that humanity be apprehended without
conditions of individuality, that is, that it be abstracted and
consequently considered as universal, occurs to humanity inasmuch as it
is brought under the consideration of the intellect, in which there is
a likeness of the specific nature, but not of the principles of
individuality.
Reply to Objection 3: There are two operations in the sensitive part.
One, in regard of impression only, and thus the operation of the senses
takes place by the senses being impressed by the sensible. The other is
formation, inasmuch as the imagination forms for itself an image of an
absent thing, or even of something never seen. Both of these operations
are found in the intellect. For in the first place there is the passion
of the passive intellect as informed by the intelligible species; and
then the passive intellect thus informed forms a definition, or a
division, or a composition, expressed by a word. Wherefore the concept
conveyed by a word is its definition; and a proposition conveys the
intellect's division or composition. Words do not therefore signify the
intelligible species themselves; but that which the intellect forms for
itself for the purpose of judging of external things.
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Whether the more universal is first in our intellectual cognition?
Objection 1: It would seem that the more universal is not first in our
intellectual cognition. For what is first and more known in its own
nature, is secondarily and less known in relation to ourselves. But
universals come first as regards their nature, because "that is first
which does not involve the existence of its correlative" (Categor. ix).
Therefore the universals are secondarily known as regards our
intellect.
Objection 2: Further, the composition precedes the simple in relation
to us. But universals are the more simple. Therefore they are known
secondarily by us.
Objection 3: Further, the Philosopher says (Phys. i, 1), that the
object defined comes in our knowledge before the parts of its
definition. But the more universal is part of the definition of the
less universal, as "animal" is part of the definition of "man. "
Therefore the universals are secondarily known by us.
Objection 4: Further, we know causes and principles by their effects.
But universals are principles. Therefore universals are secondarily
known by us.
On the contrary, "We must proceed from the universal to the singular
and individual" (Phys. i, 1)
I answer that, In our knowledge there are two things to be considered.
First, that intellectual knowledge in some degree arises from sensible
knowledge: and, because sense has singular and individual things for
its object, and intellect has the universal for its object, it follows
that our knowledge of the former comes before our knowledge of the
latter. Secondly, we must consider that our intellect proceeds from a
state of potentiality to a state of actuality; and every power thus
proceeding from potentiality to actuality comes first to an incomplete
act, which is the medium between potentiality and actuality, before
accomplishing the perfect act. The perfect act of the intellect is
complete knowledge, when the object is distinctly and determinately
known; whereas the incomplete act is imperfect knowledge, when the
object is known indistinctly, and as it were confusedly. A thing thus
imperfectly known, is known partly in act and partly in potentiality,
and hence the Philosopher says (Phys. i, 1), that "what is manifest and
certain is known to us at first confusedly; afterwards we know it by
distinguishing its principles and elements. " Now it is evident that to
know an object that comprises many things, without proper knowledge of
each thing contained in it, is to know that thing confusedly. In this
way we can have knowledge not only of the universal whole, which
contains parts potentially, but also of the integral whole; for each
whole can be known confusedly, without its parts being known. But to
know distinctly what is contained in the universal whole is to know the
less common, as to "animal" indistinctly is to know it as "animal";
whereas to know "animal" distinctly is know it as "rational" or
"irrational animal," that is, to know a man or a lion: therefore our
intellect knows "animal" before it knows man; and the same reason holds
in comparing any more universal idea with the less universal.
Moreover, as sense, like the intellect, proceeds from potentiality to
act, the same order of knowledge appears in the senses. For by sense we
judge of the more common before the less common, in reference both to
place and time; in reference to place, when a thing is seen afar off it
is seen to be a body before it is seen to be an animal; and to be an
animal before it is seen to be a man, and to be a man before it seen to
be Socrates or Plato; and the same is true as regards time, for a child
can distinguish man from not man before he distinguishes this man from
that, and therefore "children at first call men fathers, and later on
distinguish each one from the others" (Phys. i, 1). The reason of this
is clear: because he who knows a thing indistinctly is in a state of
potentiality as regards its principle of distinction; as he who knows
"genus" is in a state of potentiality as regards "difference. " Thus it
is evident that indistinct knowledge is midway between potentiality and
act.
We must therefore conclude that knowledge of the singular and
individual is prior, as regards us, to the knowledge of the universal;
as sensible knowledge is prior to intellectual knowledge. But in both
sense and intellect the knowledge of the more common precedes the
knowledge of the less common.
Reply to Objection 1: The universal can be considered in two ways.
First, the universal nature may be considered together with the
intention of universality. And since the intention of
universality---viz. the relation of one and the same to many---is due
to intellectual abstraction, the universal thus considered is a
secondary consideration. Hence it is said (De Anima i, 1) that the
"universal animal is either nothing or something secondary. " But
according to Plato, who held that universals are subsistent, the
universal considered thus would be prior to the particular, for the
latter, according to him, are mere participations of the subsistent
universals which he called ideas.
Secondly, the universal can be considered in the nature itself---for
instance, animality or humanity as existing in the individual. And thus
we must distinguish two orders of nature: one, by way of generation and
time; and thus the imperfect and the potential come first. In this way
the more common comes first in the order of nature; as appears clearly
in the generation of man and animal; for "the animal is generated
before man," as the Philosopher says (De Gener. Animal ii, 3). The
other order is the order of perfection or of the intention of nature:
for instance, act considered absolutely is naturally prior to
potentiality, and the perfect to the imperfect: thus the less common
comes naturally before the more common; as man comes before animal. For
the intention of nature does not stop at the generation of animal but
goes on to the generation of man.
Reply to Objection 2: The more common universal may be compared to the
less common, as the whole, and as the part. As the whole, considering
that in the more universal is potentially contained not only the less
universal, but also other things, as in "animal" is contained not only
"man" but also "horse. " As part, considering that the less common
contains in its idea not only the more common, but also more; as "man"
contains not only "animal" but also "rational. " Therefore "animal" in
itself comes into our knowledge before "man"; but "man" comes before
"animal" considered as part of the same idea.
Reply to Objection 3: A part can be known in two ways. First,
absolutely considered in itself; and thus nothing prevents the parts
being known before the whole, as stones are known before a house is
known. Secondly as belonging to a certain whole; and thus we must needs
know the whole before its parts. For we know a house vaguely before we
know its different parts. So likewise principles of definition are
known before the thing defined is known; otherwise the thing defined
would not be known at all. But as parts of the definition they are
known after. For we know man vaguely as man before we know how to
distinguish all that belongs to human nature.
Reply to Objection 4: The universal, as understood with the intention
of universality, is, indeed, in a way, a principle of knowledge, in so
far as the intention of universality results from the mode of
understanding by way of abstraction. But what is a principle of
knowledge is not of necessity a principle of existence, as Plato
thought: since at times we know a cause through its effect, and
substance through accidents. Wherefore the universal thus considered,
according to the opinion of Aristotle, is neither a principle of
existence, nor a substance, as he makes clear (Metaph. vii, Did. vi,
13). But if we consider the generic or specific nature itself as
existing in the singular, thus in a way it is in the nature of a formal
principle in regard to the singulars: for the singular is the result of
matter, while the idea of species is from the form. But the generic
nature is compared to the specific nature rather after the fashion of a
material principle, because the generic nature is taken from that which
is material in a thing, while the idea of species is taken from that
which is formal: thus the notion of animal is taken from the sensitive
part, whereas the notion of man is taken from the intellectual part.
Thus it is that the ultimate intention of nature is to the species and
not to the individual, or the genus: because the form is the end of
generation, while matter is for the sake of the form. Neither is it
necessary that, as regards us, knowledge of any cause or principle
should be secondary: since at times through sensible causes we become
acquainted with unknown effects, and sometimes conversely.
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Whether we can understand many things at the same time?
Objection 1: It would seem that we can understand many things at the
same time. For intellect is above time, whereas the succession of
before and after belongs to time. Therefore the intellect does not
understand different things in succession, but at the same time.
Objection 2: Further, there is nothing to prevent different forms not
opposed to each other from actually being in the same subject, as, for
instance, color and smell are in the apple. But intelligible species
are not opposed to each other. Therefore there is nothing to prevent
the same intellect being in act as regards different intelligible
species, and thus it can understand many things at the same time.
Objection 3: Further, the intellect understands a whole at the same
time, such as a man or a house. But a whole contains many parts.
Therefore the intellect understands many things at the same time.
Objection 4: Further, we cannot know the difference between two things
unless we know both at the same time (De Anima iii, 2), and the same is
to be said of any other comparison. But our intellect knows the
difference and comparison between one thing and another. Therefore it
knows many things at the same time.
On the contrary, It is said (Topic. ii, 10) that "understanding is of
one thing only, knowledge is of many. "
I answer that, The intellect can, indeed, understand many things as
one, but not as many: that is to say by "one" but not by "many"
intelligible species. For the mode of every action follows the form
which is the principle of that action. Therefore whatever things the
intellect can understand under one species, it can understand at the
same time: hence it is that God sees all things at the same time,
because He sees all in one, that is, in His Essence. But whatever
things the intellect understands under different species, it does not
understand at the same time. The reason of this is that it is
impossible for one and the same subject to be perfected at the same
time by many forms of one genus and diverse species, just as it is
impossible for one and the same body at the same time to have different
colors or different shapes. Now all intelligible species belong to one
genus, because they are the perfections of one intellectual faculty:
although the things which the species represent belong to different
genera. Therefore it is impossible for one and the same intellect to be
perfected at the same time by different intelligible species so as
actually to understand different things.
Reply to Objection 1: The intellect is above that time, which is the
measure of the movement of corporeal things. But the multitude itself
of intelligible species causes a certain vicissitude of intelligible
operations, according as one operation succeeds another. And this
vicissitude is called time by Augustine, who says (Gen. ad lit. viii,
20,22), that "God moves the spiritual creature through time. "
Reply to Objection 2: Not only is it impossible for opposite forms to
exist at the same time in the same subject, but neither can any forms
belonging to the same genus, although they be not opposed to one
another, as is clear from the examples of colors and shapes.
Reply to Objection 3: Parts can be understood in two ways. First, in a
confused way, as existing in the whole, and thus they are known through
the one form of the whole, and so are known together. In another way
they are known distinctly: thus each is known by its species; and so
they are not understood at the same time.
Reply to Objection 4: If the intellect sees the difference or
comparison between one thing and another, it knows both in relation to
their difference or comparison; just, as we have said above (ad 3), as
it knows the parts in the whole.
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Whether our intellect understands by composition and division?
Objection 1: It would seem that our intellect does not understand by
composition and division. For composition and division are only of
many; whereas the intellect cannot understand many things at the same
time. Therefore it cannot understand by composition and division.
Objection 2: Further, every composition and division implies past,
present, or future time. But the intellect abstracts from time, as also
from other individual conditions. Therefore the intellect does not
understand by composition and division.
Objection 3: Further, the intellect understands things by a process of
assimilation to them. But composition and division are not in things,
for nothing is in things but what is signified by the predicate and the
subject, and which is one and the same, provided that the composition
be true, for "man" is truly what "animal" is. Therefore the intellect
does not act by composition and division.
On the contrary, Words signify the conceptions of the intellect, as the
Philosopher says (Peri Herm. i). But in words we find composition and
division, as appears in affirmative and negative propositions.
Therefore the intellect acts by composition and division.
I answer that, The human intellect must of necessity understand by
composition and division. For since the intellect passes from
potentiality to act, it has a likeness to things which are generated,
which do not attain to perfection all at once but acquire it by
degrees: so likewise the human intellect does not acquire perfect
knowledge by the first act of apprehension; but it first apprehends
something about its object, such as its quiddity, and this is its first
and proper object; and then it understands the properties, accidents,
and the various relations of the essence. Thus it necessarily compares
one thing with another by composition or division; and from one
composition and division it proceeds to another, which is the process
of reasoning.
But the angelic and the Divine intellect, like all incorruptible
things, have their perfection at once from the beginning. Hence the
angelic and the Divine intellect have the entire knowledge of a thing
at once and perfectly; and hence also in knowing the quiddity of a
thing they know at once whatever we can know by composition, division,
and reasoning. Therefore the human intellect knows by composition,
division and reasoning. But the Divine intellect and the angelic
intellect know, indeed, composition, division, and reasoning, not by
the process itself, but by understanding the simple essence.
Reply to Objection 1: Composition and division of the intellect are
made by differentiating and comparing. Hence the intellect knows many
things by composition and division, as by knowing the difference and
comparison of things.
Reply to Objection 2: Although the intellect abstracts from the
phantasms, it does not understand actually without turning to the
phantasms, as we have said [688](A[1]; [689]Q[84], A[7]). And forasmuch
as it turns to the phantasms, composition and division of the intellect
involve time.
Reply to Objection 3: The likeness of a thing is received into the
intellect according to the mode of the intellect, not according to the
mode of the thing. Wherefore something on the part of the thing
corresponds to the composition and division of the intellect; but it
does not exist in the same way in the intellect and in the thing. For
the proper object of the human intellect is the quiddity of a material
thing, which comes under the action of the senses and the imagination.
Now in a material thing there is a twofold composition. First, there is
the composition of form with matter; and to this corresponds that
composition of the intellect whereby the universal whole is predicated
of its part: for the genus is derived from common matter, while the
difference that completes the species is derived from the form, and the
particular from individual matter. The second comparison is of accident
with subject: and to this real composition corresponds that composition
of the intellect, whereby accident is predicated of subject, as when we
say "the man is white. " Nevertheless composition of the intellect
differs from composition of things; for in the latter the things are
diverse, whereas composition of the intellect is a sign of the identity
of the components. For the above composition of the intellect does not
imply that "man" and "whiteness" are identical, but the assertion, "the
man is white," means that "the man is something having whiteness": and
the subject, which is a man, is identified with a subject having
whiteness. It is the same with the composition of form and matter: for
animal signifies that which has a sensitive nature; rational, that
which has an intellectual nature; man, that which has both; and
Socrates that which has all these things together with individual
matter; and according to this kind of identity our intellect predicates
the composition of one thing with another.
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Whether the intellect can be false?
Objection 1: It would seem that the intellect can be false; for the
Philosopher says (Metaph. vi, Did. v, 4) that "truth and falsehood are
in the mind. " But the mind and intellect are the same, as is shown
above ([690]Q[79], A[1]). Therefore falsehood may be in the mind.
Objection 2: Further, opinion and reasoning belong to the intellect.
But falsehood exists in both. Therefore falsehood can be in the
intellect.
Objection 3: Further, sin is in the intellectual faculty. But sin
involves falsehood: for "those err that work evil" (Prov. 14:22).
Therefore falsehood can be in the intellect.
On the contrary, Augustine says (QQ. 83, qu. 32), that "everyone who is
deceived, does not rightly understand that wherein he is deceived. " And
the Philosopher says (De Anima iii, 10), that "the intellect is always
true. "
I answer that, The Philosopher (De Anima iii, 6) compares intellect
with sense on this point. For sense is not deceived in its proper
object, as sight in regard to color; has accidentally through some
hindrance occurring to the sensile organ---for example, the taste of a
fever-stricken person judges a sweet thing to be bitter, through his
tongue being vitiated by ill humors. Sense, however, may be deceived as
regards common sensible objects, as size or figure; when, for example,
it judges the sun to be only a foot in diameter, whereas in reality it
exceeds the earth in size. Much more is sense deceived concerning
accidental sensible objects, as when it judges that vinegar is honey by
reason of the color being the same. The reason of this is evident; for
every faculty, as such, is "per se" directed to its proper object; and
things of this kind are always the same. Hence, as long as the faculty
exists, its judgment concerning its own proper object does not fail.
Now the proper object of the intellect is the "quiddity" of a material
thing; and hence, properly speaking, the intellect is not at fault
concerning this quiddity; whereas it may go astray as regards the
surroundings of the thing in its essence or quiddity, in referring one
thing to another, as regards composition or division, or also in the
process of reasoning. Therefore, also in regard to those propositions,
which are understood, the intellect cannot err, as in the case of first
principles from which arises infallible truth in the certitude of
scientific conclusions.
The intellect, however, may be accidentally deceived in the quiddity of
composite things, not by the defect of its organ, for the intellect is
a faculty that is independent of an organ; but on the part of the
composition affecting the definition, when, for instance, the
definition of a thing is false in relation to something else, as the
definition of a circle applied to a triangle; or when a definition is
false in itself as involving the composition of things incompatible;
as, for instance, to describe anything as "a rational winged animal. "
Hence as regards simple objects not subject to composite definitions we
cannot be deceived unless, indeed, we understand nothing whatever about
them, as is said Metaph. ix, Did. viii, 10.
Reply to Objection 1: The Philosopher says that falsehood is in the
intellect in regard to composition and division. The same answer
applies to the Second Objection concerning opinion and reasoning, and
to the Third Objection, concerning the error of the sinner, who errs in
the practical judgment of the appetible object. But in the absolute
consideration of the quiddity of a thing, and of those things which are
known thereby, the intellect is never deceived. In this sense are to be
understood the authorities quoted in proof of the opposite conclusion.
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Whether one person can understand one and the same thing better than another
can?
Objection 1: It would seem that one person cannot understand one and
the same thing better than another can. For Augustine says (QQ. 83, qu.
32), "Whoever understands a thing otherwise than as it is, does not
understand it at all. Hence it is clear that there is a perfect
understanding, than which none other is more perfect: and therefore
there are not infinite degrees of understanding a thing: nor can one
person understand a thing better than another can. "
Objection 2: Further, the intellect is true in its act of
understanding. But truth, being a certain equality between thought and
thing, is not subject to more or less; for a thing cannot be said to be
more or less equal. Therefore a thing cannot be more or less
understood.
Objection 3: Further, the intellect is the most formal of all that is
in man. But different forms cause different species. Therefore if one
man understands better than another, it would seem that they do not
belong to the same species.
On the contrary, Experience shows that some understand more profoundly
than do others; as one who carries a conclusion to its first principles
and ultimate causes understands it better than the one who reduces it
only to its proximate causes.
I answer that, A thing being understood more by one than by another may
be taken in two senses. First, so that the word "more" be taken as
determining the act of understanding as regards the thing understood;
and thus, one cannot understand the same thing more than another,
because to understand it otherwise than as it is, either better or
worse, would entail being deceived, and such a one would not understand
it, as Augustine argues (QQ. 83, qu. 32). In another sense the word
"more" can be taken as determining the act of understanding on the part
of him who understands; and so one may understand the same thing better
than someone else, through having a greater power of understanding:
just as a man may see a thing better with his bodily sight, whose power
is greater, and whose sight is more perfect. The same applies to the
intellect in two ways. First, as regards the intellect itself, which is
more perfect. For it is plain that the better the disposition of a
body, the better the soul allotted to it; which clearly appears in
things of different species: and the reason thereof is that act and
form are received into matter according to matter's capacity: thus
because some men have bodies of better disposition, their souls have a
greater power of understanding, wherefore it is said (De Anima ii, 9),
that "it is to be observed that those who have soft flesh are of apt
mind. " Secondly, this occurs in regard to the lower powers of which the
intellect has need in its operation: for those in whom the imaginative,
cogitative, and memorative powers are of better disposition, are better
disposed to understand.
The reply to the First Objection is clear from the above; likewise the
reply to the Second, for the truth of the intellect consists in the
intellect understanding a thing as it is.
Reply to Objection 3: The difference of form which is due only to the
different disposition of matter, causes not a specific but only a
numerical difference: for different individuals have different forms,
diversified according to the difference of matter.
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Whether the intellect understands the indivisible before the divisible?
Objection 1: It would seem that the intellect understands the
indivisible before the divisible. For the Philosopher says (Phys. i, 1)
that "we understand and know from the knowledge of principles and
elements. " But principles are indivisible, and elements are of
divisible things. Therefore the indivisible is known to us before the
divisible.
Objection 2: Further, the definition of a thing contains what is known
previously, for a definition "proceeds from the first and more known,"
as is said Topic. vi, 4. But the indivisible is part of the definition
of the divisible; as a point comes into the definition of a line; for
as Euclid says, "a line is length without breadth, the extremities of
which are points"; also unity comes into the definition of number, for
"number is multitude measured by one," as is said Metaph. x, Did. ix,
6. Therefore our intellect understands the indivisible before the
divisible.
Objection 3: Further, "Like is known by like. " But the indivisible is
more like to the intellect than is the divisible; because "the
intellect is simple" (De Anima iii, 4). Therefore our intellect first
knows the indivisible.
On the contrary, It is said (De Anima iii, 6) that "the indivisible is
expressed as a privation. " But privation is known secondarily.
Therefore likewise is the indivisible.
I answer that, The object of our intellect in its present state is the
quiddity of a material thing, which it abstracts from the phantasms, as
above stated ([691]Q[84], A[7]). And since that which is known first
and of itself by our cognitive power is its proper object, we must
consider its relationship to that quiddity in order to discover in what
order the indivisible is known. Now the indivisible is threefold, as is
said De Anima iii, 6. First, the continuous is indivisible, since
actually it is undivided, although potentially divisible: and this
indivisible is known to us before its division, which is a division
into parts: because confused knowledge is prior to distinct knowledge,
as we have said above [692](A[3]). Secondly, the indivisible is so
called in relation to species, as man's reason is something
indivisible. This way, also, the indivisible is understood before its
division into logical parts, as we have said above (De Anima iii, 6);
and again before the intellect disposes and divides by affirmation and
negation. The reason of this is that both these kinds of indivisible
are understood by the intellect of itself, as being its proper object.
The third kind of indivisible is what is altogether indivisible, as a
point and unity, which cannot be divided either actually or
potentially. And this indivisible is known secondarily, through the
privation of divisibility. Wherefore a point is defined by way of
privation "as that which has no parts"; and in like manner the notion
of "one" is that is "indivisible," as stated in Metaph. x, Did. ix, 1.
And the reason of this is that this indivisible has a certain
opposition to a corporeal being, the quiddity of which is the primary
and proper object of the intellect.
But if our intellect understood by participation of certain separate
indivisible (forms), as the Platonists maintained, it would follow that
a like indivisible is understood primarily; for according to the
Platonists what is first is first participated by things.
Reply to Objection 1: In the acquisition of knowledge, principles and
elements are not always (known) first: for sometimes from sensible
effects we arrive at the knowledge of principles and intelligible
causes. But in perfect knowledge, the knowledge of effects always
depends on the knowledge of principles and elements: for as the
Philosopher says in the same passage: "Then do we consider that we
know, when we can resolve principles into their causes. "
Reply to Objection 2: A point is not included in the definition of a
line in general: for it is manifest that in a line of indefinite
length, and in a circular line, there is no point, save potentially.
Euclid defines a finite straight line: and therefore he mentions a
point in the definition, as the limit in the definition of that which
is limited. Unity is the measure of number: wherefore it is included in
the definition of a measured number. But it is not included in the
definition of the divisible, but rather conversely.
Reply to Objection 3: The likeness through which we understand is the
species of the known in the knower; therefore a thing is known first,
not on account of its natural likeness to the cognitive power, but on
account of the power's aptitude for the object: otherwise sight would
perceive hearing rather than color.
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WHAT OUR INTELLECT KNOWS IN MATERIAL THINGS (FOUR ARTICLES)
We now have to consider what our intellect knows in material things.
Under this head there are four points of inquiry:
(1) Whether it knows singulars?
(2) Whether it knows the infinite?
(3) Whether it knows contingent things?
(4) Whether it knows future things?
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Whether our intellect knows singulars?
Objection 1: It would seem that our intellect knows singulars. For
whoever knows composition, knows the terms of composition. But our
intellect knows this composition; "Socrates is a man": for it belongs
to the intellect to form a proposition. Therefore our intellect knows
this singular, Socrates.
Objection 2: Further, the practical intellect directs to action. But
action has relation to singular things. Therefore the intellect knows
the singular.
Objection 3: Further, our intellect understands itself. But in itself
it is a singular, otherwise it would have no action of its own; for
actions belong to singulars. Therefore our intellect knows singulars.
Objection 4: Further, a superior power can do whatever is done by an
inferior power. But sense knows the singular. Much more, therefore, can
the intellect know it.
On the contrary, The Philosopher says (Phys. i, 5), that "the universal
is known by reason; and the singular is known by sense. "
I answer that, Our intellect cannot know the singular in material
things directly and primarily. The reason of this is that the principle
of singularity in material things is individual matter, whereas our
intellect, as have said above ([693]Q[85], A[1]), understands by
abstracting the intelligible species from such matter. Now what is
abstracted from individual matter is the universal. Hence our intellect
knows directly the universal only. But indirectly, and as it were by a
kind of reflection, it can know the singular, because, as we have said
above ([694]Q[85], A[7]), even after abstracting the intelligible
species, the intellect, in order to understand, needs to turn to the
phantasms in which it understands the species, as is said De Anima iii,
7. Therefore it understands the universal directly through the
intelligible species, and indirectly the singular represented by the
phantasm. And thus it forms the proposition "Socrates is a man. "
Wherefore the reply to the first objection is clear.
Reply to Objection 2: The choice of a particular thing to be done is as
the conclusion of a syllogism formed by the practical intellect, as is
said Ethic. vii, 3. But a singular proposition cannot be directly
concluded from a universal proposition, except through the medium of a
singular proposition. Therefore the universal principle of the
practical intellect does not move save through the medium of the
particular apprehension of the sensitive part, as is said De Anima iii,
11.
Reply to Objection 3: Intelligibility is incompatible with the singular
not as such, but as material, for nothing can be understood otherwise
than immaterially. Therefore if there be an immaterial singular such as
the intellect, there is no reason why it should not be intelligible.
Reply to Objection 4: The higher power can do what the lower power can,
but in a more eminent way. Wherefore what the sense knows materially
and concretely, which is to know the singular directly, the intellect
knows immaterially and in the abstract, which is to know the universal.
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Whether our intellect can know the infinite?
Objection 1: It would seem that our intellect can know the infinite.
For God excels all infinite things. But our intellect can know God, as
we have said above ([695]Q[12], A[1]). Much more, therefore, can our
intellect know all other infinite things.
Objection 2: Further, our intellect can naturally know "genera" and
"species. " But there is an infinity of species in some genera, as in
number, proportion, and figure. Therefore our intellect can know the
infinite.
Objection 3: Further, if one body can coexist with another in the same
place, there is nothing to prevent an infinite number of bodies being
in one place. But one intelligible species can exist with another in
the same intellect, for many things can be habitually known at the same
time. Therefore our intellect can have an habitual knowledge of an
infinite number of things.
