QUESTION 14: OF GOD'S KNOWLEDGE
Having considered what belongs to the divine substance, we have now to
treat of God's operation. And since one kind of operation is immanent,
and another kind of operation proceeds to the exterior effect, we treat
first of knowledge and of will (for understanding abides in the
intelligent agent, and will is in the one who wills); and afterwards of
the power of God, the principle of the divine operation as proceeding to
the exterior effect. Now because to understand is a kind of life, after
treating of the divine knowledge, we consider truth and falsehood.
Further, as everything known is in the knower, and the types of things as
existing in the knowledge of God are called ideas, to the consideration
of knowledge will be added the treatment of ideas.
Concerning knowledge, there are sixteen points for inquiry:
(1) Whether there is knowledge in God?
(2) Whether God understands Himself?
(3) Whether He comprehends Himself?
(4) Whether His understanding is His substance?
(5) Whether He understands other things besides Himself?
(6) Whether He has a proper knowledge of them?
(7) Whether the knowledge of God is discursive?
(8) Whether the knowledge of God is the cause of things?
(9) Whether God has knowledge of non-existing things?
(10) Whether He has knowledge of evil?
(11) Whether He has knowledge of individual things?
(12) Whether He knows the infinite?
(13) Whether He knows future contingent things?
(14) Whether He knows enunciable things?
(15) Whether the knowledge of God is variable?
(16) Whether God has speculative or practical knowledge of things?
Article 1: Whether there is knowledge [*Scientia]?
Objection 1: It seems that in God there is not knowledge. For knowledge is a
habit; and habit does not belong to God, since it is the mean between
potentiality and act. Therefore knowledge is not in God.
Objection 2: Further, since science is about conclusions, it is a kind of
knowledge caused by something else which is the knowledge of principles.
But nothing is caused in God; therefore science is not in God.
On the contrary, The Apostle says, "O the depth of the riches of the
wisdom and of the knowledge of God" (Rm. 11:33).
I answer that, In God there exists the most perfect knowledge. To prove
this, we must note that intelligent beings are distinguished from
non-intelligent beings in that the latter possess only their own form;
whereas the intelligent being is naturally adapted to have also the form
of some other thing; for the idea of the thing known is in the knower.
Hence it is manifest that the nature of a non-intelligent being is more
contracted and limited; whereas the nature of intelligent beings has a
greater amplitude and extension; therefore the Philosopher says (De Anima
iii) that "the soul is in a sense all things." Now the contraction of
the form comes from the matter. Hence, as we have said above (Question , Article )
forms according as they are the more immaterial, approach more nearly to
a kind of infinity. Therefore it is clear that the immateriality of a
thing is the reason why it is cognitive; and according to the mode of
immateriality is the mode of knowledge. Hence it is said in De Anima ii
that plants do not know, because they are wholly material. But sense is
cognitive because it can receive images free from matter, and the
intellect is still further cognitive, because it is more separated from
matter and unmixed, as said in De Anima iii. Since therefore God is in
the highest degree of immateriality as stated above (Question , Article ), it
follows that He occupies the highest place in knowledge.
Reply to Objection 1: Because perfections flowing from God to creatures exist in
a higher state in God Himself (Question , Article ), whenever a name taken from
any created perfection is attributed to God, it must be separated in its
signification from anything that belongs to that imperfect mode proper to
creatures. Hence knowledge is not a quality of God, nor a habit; but
substance and pure act.
Reply to Objection 2: Whatever is divided and multiplied in creatures exists in
God simply and unitedly (Question , Article ). Now man has different kinds of
knowledge, according to the different objects of His knowledge. He has
"intelligence" as regards the knowledge of principles; he has "science"
as regards knowledge of conclusions; he has "wisdom," according as he
knows the highest cause; he has "counsel" or "prudence," according as he
knows what is to be done. But God knows all these by one simple act of
knowledge, as will be shown (Article ). Hence the simple knowledge of God can
be named by all these names; in such a way, however, that there must be
removed from each of them, so far as they enter into divine predication,
everything that savors of imperfection; and everything that expresses
perfection is to be retained in them. Hence it is said, "With Him is
wisdom and strength, He hath counsel and understanding" (Job 12:13).
Reply to Objection 3: Knowledge is according to the mode of the one who knows;
for the thing known is in the knower according to the mode of the knower.
Now since the mode of the divine essence is higher than that of
creatures, divine knowledge does not exist in God after the mode of
created knowledge, so as to be universal or particular, or habitual, or
potential, or existing according to any such mode.
Article 2: Whether God understands Himself?
Objection 1: It seems that God does not understand Himself. For it is said by
the Philosopher (De Causis), "Every knower who knows his own essence,
returns completely to his own essence." But God does not go out from His
own essence, nor is He moved at all; thus He cannot return to His own
essence. Therefore He does not know His own essence.
Objection 2: Further, to understand is a kind of passion and movement, as the
Philosopher says (De Anima iii); and knowledge also is a kind of
assimilation to the object known; and the thing known is the perfection
of the knower. But nothing is moved, or suffers, or is made perfect by
itself, "nor," as Hilary says (De Trin. iii), "is a thing its own
likeness." Therefore God does not understand Himself.
Objection 3: Further, we are like to God chiefly in our intellect, because we
are the image of God in our mind, as Augustine says (Gen. ad lit. vi).
But our intellect understands itself, only as it understands other
things, as is said in De Anima iii. Therefore God understands Himself
only so far perchance as He understands other things.
On the contrary, It is written: "The things that are of God no man
knoweth, but the Spirit of God" (1 Cor. 2:11).
I answer that, God understands Himself through Himself. In proof whereof
it must be known that although in operations which pass to an external
effect, the object of the operation, which is taken as the term, exists
outside the operator; nevertheless in operations that remain in the
operator, the object signified as the term of operation, resides in the
operator; and accordingly as it is in the operator, the operation is
actual. Hence the Philosopher says (De Anima iii) that "the sensible in
act is sense in act, and the intelligible in act is intellect in act."
For the reason why we actually feel or know a thing is because our
intellect or sense is actually informed by the sensible or intelligible
species. And because of this only, it follows that sense or intellect is
distinct from the sensible or intelligible object, since both are in
Since therefore God has nothing in Him of potentiality, but is pure act,
His intellect and its object are altogether the same; so that He neither
is without the intelligible species, as is the case with our intellect
when it understands potentially; nor does the intelligible species differ
from the substance of the divine intellect, as it differs in our
intellect when it understands actually; but the intelligible species
itself is the divine intellect itself, and thus God understands Himself
Reply to Objection 1: Return to its own essence means only that a thing subsists
in itself. Inasmuch as the form perfects the matter by giving it
existence, it is in a certain way diffused in it; and it returns to
itself inasmuch as it has existence in itself. Therefore those cognitive
faculties which are not subsisting, but are the acts of organs, do not
know themselves, as in the case of each of the senses; whereas those
cognitive faculties which are subsisting, know themselves; hence it is
said in De Causis that, "whoever knows his essence returns to it." Now it
supremely belongs to God to be self-subsisting. Hence according to this
mode of speaking, He supremely returns to His own essence, and knows
Reply to Objection 2: Movement and passion are taken equivocally, according as to
understand is described as a kind of movement or passion, as stated in De
Anima iii. For to understand is not a movement that is an act of
something imperfect passing from one to another, but it is an act,
existing in the agent itself, of something perfect. Likewise that the
intellect is perfected by the intelligible object, i.e. is assimilated to
it, this belongs to an intellect which is sometimes in potentiality;
because the fact of its being in a state of potentiality makes it differ
from the intelligible object and assimilates it thereto through the
intelligible species, which is the likeness of the thing understood, and
makes it to be perfected thereby, as potentiality is perfected by act. On
the other hand, the divine intellect, which is no way in potentiality, is
not perfected by the intelligible object, nor is it assimilated thereto,
but is its own perfection, and its own intelligible object.
Reply to Objection 3: Existence in nature does not belong to primary matter,
which is a potentiality, unless it is reduced to act by a form. Now our
passive intellect has the same relation to intelligible objects as
primary matter has to natural things; for it is in potentiality as
regards intelligible objects, just as primary matter is to natural
things. Hence our passive intellect can be exercised concerning
intelligible objects only so far as it is perfected by the intelligible
species of something; and in that way it understands itself by an
intelligible species, as it understands other things: for it is manifest
that by knowing the intelligible object it understands also its own act
of understanding, and by this act knows the intellectual faculty. But God
is a pure act in the order of existence, as also in the order of
intelligible objects; therefore He understands Himself through Himself.
Article 3: Whether God comprehends Himself?
Objection 1: It seems that God does not comprehend Himself. For Augustine says
(Octog. Tri. Quaest. xv), that "whatever comprehends itself is finite as
regards itself." But God is in all ways infinite. Therefore He does not
Objection 2: If it is said that God is infinite to us, and finite to Himself,
it can be urged to the contrary, that everything in God is truer than it
is in us. If therefore God is finite to Himself, but infinite to us, then
God is more truly finite than infinite; which is against what was laid
down above (Question , Article ). Therefore God does not comprehend Himself.
On the contrary, Augustine says (Octog. Tri. Quaest. xv), that
"Everything that understands itself, comprehends itself." But God
understands Himself. Therefore He comprehends Himself.
I answer that, God perfectly comprehends Himself, as can be thus proved.
A thing is said to be comprehended when the end of the knowledge of it
is attained, and this is accomplished when it is known as perfectly as it
is knowable; as, for instance, a demonstrable proposition is comprehended
when known by demonstration, not, however, when it is known by some
probable reason. Now it is manifest that God knows Himself as perfectly
as He is perfectly knowable. For everything is knowable according to the
mode of its own actuality; since a thing is not known according as it is
in potentiality, but in so far as it is in actuality, as said in Metaph.
ix. Now the power of God in knowing is as great as His actuality in
existing; because it is from the fact that He is in act and free from all
matter and potentiality, that God is cognitive, as shown above (Articles ,2).
Whence it is manifest that He knows Himself as much as He is knowable;
and for that reason He perfectly comprehends Himself.
Reply to Objection 1: The strict meaning of "comprehension" signifies that one
thing holds and includes another; and in this sense everything
comprehended is finite, as also is everything included in another. But
God is not said to be comprehended by Himself in this sense, as if His
intellect were a faculty apart from Himself, and as if it held and
included Himself; for these modes of speaking are to be taken by way of
negation. But as God is said to be in Himself, forasmuch as He is not
contained by anything outside of Himself; so He is said to be
comprehended by Himself, forasmuch as nothing in Himself is hidden from
Himself. For Augustine says (De Vid. Deum. ep. cxii), "The whole is
comprehended when seen, if it is seen in such a way that nothing of it is
hidden from the seer."
Reply to Objection 2: When it is said, "God is finite to Himself," this is to be
understood according to a certain similitude of proportion, because He
has the same relation in not exceeding His intellect, as anything finite
has in not exceeding finite intellect. But God is not to be called finite
to Himself in this sense, as if He understood Himself to be something
Article 4: Whether the act of God's intellect is His substance?
Objection 1: It seems that the act of God's intellect is not His substance.
For to understand is an operation. But an operation signifies something
proceeding from the operator. Therefore the act of God's intellect is not
Objection 2: Further, to understand one's act of understanding, is to
understand something that is neither great nor chiefly understood, and
but secondary and accessory. If therefore God be his own act of
understanding, His act of understanding will be as when we understand our
act of understanding: and thus God's act of understanding will not be
Objection 3: Further, every act of understanding means understanding
something. When therefore God understands Himself, if He Himself is not
distinct from this act of understanding, He understands that He
understands Himself; and so on to infinity. Therefore the act of God's
intellect is not His substance.
On the contrary, Augustine says (De Trin. vii), "In God to be is the
same as to be wise." But to be wise is the same thing as to understand.
Therefore in God to be is the same thing as to understand. But God's
existence is His substance, as shown above (Question , Article ). Therefore the
act of God's intellect is His substance.
I answer that, It must be said that the act of God's intellect is His
substance. For if His act of understanding were other than His substance,
then something else, as the Philosopher says (Metaph. xii), would be the
act and perfection of the divine substance, to which the divine substance
would be related, as potentiality is to act, which is altogether
impossible; because the act of understanding is the perfection and act of
the one understanding. Let us now consider how this is. As was laid down
above (Article ), to understand is not an act passing to anything extrinsic;
for it remains in the operator as his own act and perfection; as
existence is the perfection of the one existing: just as existence
follows on the form, so in like manner to understand follows on the
intelligible species. Now in God there is no form which is something
other than His existence, as shown above (Question ). Hence as His essence
itself is also His intelligible species, it necessarily follows that His
act of understanding must be His essence and His existence.
Thus it follows from all the foregoing that in God, intellect, and the
object understood, and the intelligible species, and His act of
understanding are entirely one and the same. Hence when God is said to be
understanding, no kind of multiplicity is attached to His substance.
Reply to Objection 1: To understand is not an operation proceeding out of the
operator, but remaining in him.
Reply to Objection 2: When that act of understanding which is not subsistent is
understood, something not great is understood; as when we understand our
act of understanding; and so this cannot be likened to the act of the
divine understanding which is subsistent.
Thus appears the Reply to the Third Objection. For the act of divine
understanding subsists in itself, and belongs to its very self and is not
another's; hence it need not proceed to infinity.
Article 5: Whether God knows things other than Himself?
Objection 1: It seems that God does not know things besides Himself. For all
other things but God are outside of God. But Augustine says (Octog. Tri.
Quaest. qu. xlvi) that "God does not behold anything out of Himself."
Therefore He does not know things other than Himself.
Objection 2: Further, the object understood is the perfection of the one who
understands. If therefore God understands other things besides Himself,
something else will be the perfection of God, and will be nobler than He;
which is impossible.
Objection 3: Further, the act of understanding is specified by the
intelligible object, as is every other act from its own object. Hence the
intellectual act is so much the nobler, the nobler the object understood.
But God is His own intellectual act. If therefore God understands
anything other than Himself, then God Himself is specified by something
else than Himself; which cannot be. Therefore He does not understand
things other than Himself.
On the contrary, It is written: "All things are naked and open to His
eyes" (Heb. 4:13).
I answer that, God necessarily knows things other than Himself. For it
is manifest that He perfectly understands Himself; otherwise His
existence would not be perfect, since His existence is His act of
understanding. Now if anything is perfectly known, it follows of
necessity that its power is perfectly known. But the power of anything
can be perfectly known only by knowing to what its power extends. Since
therefore the divine power extends to other things by the very fact that
it is the first effective cause of all things, as is clear from the
aforesaid (Question , Article ), God must necessarily know things other than
Himself. And this appears still more plainly if we add that the every
existence of the first effective cause---viz. God---is His own act of
understanding. Hence whatever effects pre-exist in God, as in the first
cause, must be in His act of understanding, and all things must be in Him
according to an intelligible mode: for everything which is in another, is
in it according to the mode of that in which it is.
Now in order to know how God knows things other than Himself, we must
consider that a thing is known in two ways: in itself, and in another. A
thing is known in itself when it is known by the proper species adequate
to the knowable object; as when the eye sees a man through the image of a
man. A thing is seen in another through the image of that which contains
it; as when a part is seen in the whole by the image of the whole; or
when a man is seen in a mirror by the image in the mirror, or by any
other mode by which one thing is seen in another.
So we say that God sees Himself in Himself, because He sees Himself
through His essence; and He sees other things not in themselves, but in
Himself; inasmuch as His essence contains the similitude of things other
Reply to Objection 1: The passage of Augustine in which it is said that God "sees
nothing outside Himself" is not to be taken in such a way, as if God saw
nothing outside Himself, but in the sense that what is outside Himself He
does not see except in Himself, as above explained.
Reply to Objection 2: The object understood is a perfection of the one
understanding not by its substance, but by its image, according to which
it is in the intellect, as its form and perfection, as is said in De
Anima iii. For "a stone is not in the soul, but its image." Now those
things which are other than God are understood by God, inasmuch as the
essence of God contains their images as above explained; hence it does
not follow that there is any perfection in the divine intellect other
than the divine essence.
Reply to Objection 3: The intellectual act is not specified by what is understood
in another, but by the principal object understood in which other things
are understood. For the intellectual act is specified by its object,
inasmuch as the intelligible form is the principle of the intellectual
operation: since every operation is specified by the form which is its
principle of operation; as heating by heat. Hence the intellectual
operation is specified by that intelligible form which makes the
intellect in act. And this is the image of the principal thing
understood, which in God is nothing but His own essence in which all
images of things are comprehended. Hence it does not follow that the
divine intellectual act, or rather God Himself, is specified by anything
else than the divine essence itself.
Article 6: Whether God knows things other than Himself by proper knowledge?
Objection 1: It seems that God does not know things other than Himself by
proper knowledge. For, as was shown (Article ), God knows things other than
Himself, according as they are in Himself. But other things are in Him as
in their common and universal cause, and are known by God as in their
first and universal cause. This is to know them by general, and not by
proper knowledge. Therefore God knows things besides Himself by general,
and not by proper knowledge.
Objection 2: Further, the created essence is as distant from the divine
essence, as the divine essence is distant from the created essence. But
the divine essence cannot be known by the created essence, as said above
(Question /Article ). Therefore neither can the created essence be known by the
divine essence. Thus as God knows only by His essence, it follows that He
does not know what the creature is in its essence, so as to know "what it
is," which is to have proper knowledge of it.
Objection 3: Further, proper knowledge of a thing can come only through its
proper ratio. But as God knows all things by His essence, it seems that
He does not know each thing by its proper ratio; for one thing cannot be
the proper ratio of many and diverse things. Therefore God has not a
proper knowledge of things, but a general knowledge; for to know things
otherwise than by their proper ratio is to have only a common and general
knowledge of them.
On the contrary, To have a proper knowledge of things is to know them
not only in general, but as they are distinct from each other. Now God
knows things in that manner. Hence it is written that He reaches "even to
the division of the soul and the spirit, of the joints also and the
marrow, and is a discerner of thoughts and intents of the heart; neither
is there any creature invisible in His sight" (Heb. 4:12,13).
I answer that, Some have erred on this point, saying that God knows
things other than Himself only in general, that is, only as beings. For
as fire, if it knew the nature of heat, and all things else in so far as
they are hot; so God, through knowing Himself as the principle of being,
knows the nature of being, and all other things in so far as they are
But this cannot be. For to know a thing in general and not in
particular, is to have an imperfect knowledge. Hence our intellect, when
it is reduced from potentiality to act, acquires first a universal and
confused knowledge of things, before it knows them in particular; as
proceeding from the imperfect to the perfect, as is clear from Phys. i.
If therefore the knowledge of God regarding things other than Himself is
only universal and not special, it would follow that His understanding
would not be absolutely perfect; therefore neither would His being be
perfect; and this is against what was said above (Question , Article ). We must
therefore hold that God knows things other than Himself with a proper
knowledge; not only in so far as being is common to them, but in so far
as one is distinguished from the other. In proof thereof we may observe
that some wishing to show that God knows many things by one, bring
forward some examples, as, for instance, that if the centre knew itself,
it would know all lines that proceed from the centre; or if light knew
itself, it would know all colors.
Now these examples although they are similar in part, namely, as regards
universal causality, nevertheless they fail in this respect, that
multitude and diversity are caused by the one universal principle, not as
regards that which is the principle of distinction, but only as regards
that in which they communicate. For the diversity of colors is not caused
by the light only, but by the different disposition of the diaphanous
medium which receives it; and likewise, the diversity of the lines is
caused by their different position. Hence it is that this kind of
diversity and multitude cannot be known in its principle by proper
knowledge, but only in a general way. In God, however, it is otherwise.
For it was shown above (Question , Article ) that whatever perfection exists in
any creature, wholly pre-exists and is contained in God in an excelling
manner. Now not only what is common to creatures--viz. being---belongs to
their perfection, but also what makes them distinguished from each other;
as living and understanding, and the like, whereby living beings are
distinguished from the non-living, and the intelligent from the
non-intelligent. Likewise every form whereby each thing is constituted in
its own species, is a perfection; and thus all things pre-exist in God,
not only as regards what is common to all, but also as regards what
distinguishes one thing from another. And therefore as God contains all
perfections in Himself, the essence of God is compared to all other
essences of things, not as the common to the proper, as unity is to
numbers, or as the centre (of a circle) to the (radiating) lines; but as
perfect acts to imperfect; as if I were to compare man to animal; or six,
a perfect number, to the imperfect numbers contained under it. Now it is
manifest that by a perfect act imperfect acts can be known not only in
general, but also by proper knowledge; thus, for example, whoever knows a
man, knows an animal by proper knowledge; and whoever knows the number
six, knows the number three also by proper knowledge.
As therefore the essence of God contains in itself all the perfection
contained in the essence of any other being, and far more, God can know
in Himself all of them with proper knowledge. For the nature proper to
each thing consists in some degree of participation in the divine
perfection. Now God could not be said to know Himself perfectly unless He
knew all the ways in which His own perfection can be shared by others.
Neither could He know the very nature of being perfectly, unless He knew
all modes of being. Hence it is manifest that God knows all things with
proper knowledge, in their distinction from each other.
Reply to Objection 1: So to know a thing as it is in the knower, may be
understood in two ways. In one way this adverb "so" imports the mode of
knowledge on the part of the thing known; and in that sense it is false.
For the knower does not always know the object known according to the
existence it has in the knower; since the eye does not know a stone
according to the existence it has in the eye; but by the image of the
stone which is in the eye, the eye knows the stone according to its
existence outside the eye. And if any knower has a knowledge of the
object known according to the (mode of) existence it has in the knower,
the knower nevertheless knows it according to its (mode of) existence
outside the knower; thus the intellect knows a stone according to the
intelligible existence it has in the intellect, inasmuch as it knows that
it understands; while nevertheless it knows what a stone is in its own
nature. If however the adverb 'so' be understood to import the mode (of
knowledge) on the part of the knower, in that sense it is true that only
the knower has knowledge of the object known as it is in the knower; for
the more perfectly the thing known is in the knower, the more perfect is
the mode of knowledge.
We must say therefore that God not only knows that all things are in
Himself; but by the fact that they are in Him, He knows them in their own
nature and all the more perfectly, the more perfectly each one is in Him.
Reply to Objection 2: The created essence is compared to the essence of God as
the imperfect to the perfect act. Therefore the created essence cannot
sufficiently lead us to the knowledge of the divine essence, but rather
Reply to Objection 3: The same thing cannot be taken in an equal manner as the
ratio of different things. But the divine essence excels all creatures.
Hence it can be taken as the proper ration of each thing according to
the diverse ways in which diverse creatures participate in, and imitate
Article 7: Whether the knowledge of God is discursive?
Objection 1: It seems that the knowledge of God is discursive. For the
knowledge of God is not habitual knowledge, but actual knowledge. Now the
Philosopher says (Topic. ii): "The habit of knowledge may regard many
things at once; but actual understanding regards only one thing at a
time." Therefore as God knows many things, Himself and others, as shown
above (Articles 2,5), it seems that He does not understand all at once, but
discourses from one to another.
Objection 2: Further, discursive knowledge is to know the effect through its
cause. But God knows things through Himself; as an effect (is known)
through its cause. Therefore His knowledge is discursive.
Objection 3: Further, God knows each creature more perfectly than we know it.
But we know the effects in their created causes; and thus we go
discursively from causes to things caused. Therefore it seems that the
same applies to God.
On the contrary, Augustine says (De Trin. xv), "God does not see all
things in their particularity or separately, as if He saw alternately
here and there; but He sees all things together at once."
I answer that, In the divine knowledge there is no discursion; the proof of which is as follows. In our knowledge there is a twofold discursion: one is according to succession only, as when we have actually understood anything, we turn ourselves to understand something else; while the other mode of discursion is according to causality, as when through principles we arrive at the knowledge of conclusions. The first kind of discursion cannot belong to God. For many things, which we understand in succession if each is considered in itself, we understand simultaneously if we see them in some one thing; if, for instance, we understand the parts in the whole, or see different things in a mirror. Now God sees all things in one (thing), which is Himself. Therefore God sees all things together, and not successively. Likewise the second mode of discursion cannot be applied to God. First, because this second mode of discursion presupposes the first mode; for whosoever proceeds from principles to conclusions does not consider both at once; secondly, because to discourse thus is to proceed from the known to the unknown. Hence it is manifest that when the first is known, the second is still unknown; and thus the second is known not in the first, but from the first. Now the term discursive reasoning is attained when the second is seen in the first, by resolving the effects into their causes; and then the discursion ceases. Hence as God sees His effects in Himself as their cause, His knowledge is not discursive.
Reply to Objection 1: Altogether there is only one act of understanding in
itself, nevertheless many things may be understood in one (medium), as
Reply to Objection 2: God does not know by their cause, known, as it were
previously, effects unknown; but He knows the effects in the cause; and
hence His knowledge is not discursive, as was shown above.
Reply to Objection 3: God sees the effects of created causes in the causes
themselves, much better than we can; but still not in such a manner that
the knowledge of the effects is caused in Him by the knowledge of the
created causes, as is the case with us; and hence His knowledge is not
Article 8: Whether the knowledge of God is the cause of things?
Objection 1: It seems that the knowledge of God is not the cause of things.
For Origen says, on Rm. 8:30, "Whom He called, them He also justified,"
etc.: "A thing will happen not because God knows it as future; but
because it is future, it is on that account known by God, before it
Objection 2: Further, given the cause, the effect follows. But the knowledge
of God is eternal. Therefore if the knowledge of God is the cause of
things created, it seems that creatures are eternal.
Objection 3: Further, "The thing known is prior to knowledge, and is its
measure," as the Philosopher says (Metaph. x). But what is posterior and
measured cannot be a cause. Therefore the knowledge of God is not the
cause of things.
On the contrary, Augustine says (De Trin. xv), "Not because they are,
does God know all creatures spiritual and temporal, but because He knows
them, therefore they are."
I answer that, The knowledge of God is the cause of things. For the
knowledge of God is to all creatures what the knowledge of the artificer
is to things made by his art. Now the knowledge of the artificer is the
cause of the things made by his art from the fact that the artificer
works by his intellect. Hence the form of the intellect must be the
principle of action; as heat is the principle of heating. Nevertheless,
we must observe that a natural form, being a form that remains in that to
which it gives existence, denotes a principle of action according only as
it has an inclination to an effect; and likewise, the intelligible form
does not denote a principle of action in so far as it resides in the one
who understands unless there is added to it the inclination to an effect,
which inclination is through the will. For since the intelligible form
has a relation to opposite things (inasmuch as the same knowledge relates
to opposites), it would not produce a determinate effect unless it were
determined to one thing by the appetite, as the Philosopher says
(Metaph. ix). Now it is manifest that God causes things by His intellect,
since His being is His act of understanding; and hence His knowledge must
be the cause of things, in so far as His will is joined to it. Hence the
knowledge of God as the cause of things is usually called the "knowledge
Reply to Objection 1: Origen spoke in reference to that aspect of knowledge to
which the idea of causality does not belong unless the will is joined to
it, as is said above.
But when he says the reason why God foreknows some things is because
they are future, this must be understood according to the cause of
consequence, and not according to the cause of essence. For if things are
in the future, it follows that God knows them; but not that the futurity
of things is the cause why God knows them.
Reply to Objection 2: The knowledge of God is the cause of things according as
things are in His knowledge. Now that things should be eternal was not in
the knowledge of God; hence although the knowledge of God is eternal, it
does not follow that creatures are eternal.
Reply to Objection 3: Natural things are midway between the knowledge of God and
our knowledge: for we receive knowledge from natural things, of which God
is the cause by His knowledge. Hence, as the natural objects of knowledge
are prior to our knowledge, and are its measure, so, the knowledge of God
is prior to natural things, and is the measure of them; as, for instance,
a house is midway between the knowledge of the builder who made it, and
the knowledge of the one who gathers his knowledge of the house from the
house already built.
Article 9: Whether God has knowledge of things that are not?
Objection 1: It seems that God has not knowledge of things that are not. For
the knowledge of God is of true things. But "truth" and "being" are
convertible terms. Therefore the knowledge of God is not of things that
Objection 2: Further, knowledge requires likeness between the knower and the
thing known. But those things that are not cannot have any likeness to
God, Who is very being. Therefore what is not, cannot be known by God.
Objection 3: Further, the knowledge of God is the cause of what is known by
Him. But it is not the cause of things that are not, because a thing that
is not, has no cause. Therefore God has no knowledge of things that are
On the contrary, The Apostle says: "Who . . . calleth those things that are not as those that are" (Rm. 4:17).
I answer that, God knows all things whatsoever that in any way are. Now
it is possible that things that are not absolutely, should be in a
certain sense. For things absolutely are which are actual; whereas things
which are not actual, are in the power either of God Himself or of a
creature, whether in active power, or passive; whether in power of
thought or of imagination, or of any other manner of meaning whatsoever.
Whatever therefore can be made, or thought, or said by the creature, as
also whatever He Himself can do, all are known to God, although they are
not actual. And in so far it can be said that He has knowledge even of
things that are not.
Now a certain difference is to be noted in the consideration of those
things that are not actual. For though some of them may not be in act
now, still they were, or they will be; and God is said to know all these
with the knowledge of vision: for since God's act of understanding, which
is His being, is measured by eternity; and since eternity is without
succession, comprehending all time, the present glance of God extends
over all time, and to all things which exist in any time, as to objects
present to Him. But there are other things in God's power, or the
creature's, which nevertheless are not, nor will be, nor were; and as
regards these He is said to have knowledge, not of vision, but of simple
intelligence. This is so called because the things we see around us have
distinct being outside the seer.
Reply to Objection 1: Those things that are not actual are true in so far as they
are in potentiality; for it is true that they are in potentiality; and as
such they are known by God.
Reply to Objection 2: Since God is very being everything is, in so far as it
participates in the likeness of God; as everything is hot in so far as it
participates in heat. So, things in potentiality are known by God,
although they are not in act.
Reply to Objection 3: The knowledge of God, joined to His will is the cause of
things. Hence it is not necessary that what ever God knows, is, or was,
or will be; but only is this necessary as regards what He wills to be, or
permits to be. Further, it is in the knowledge of God not that they be,
but that they be possible.
Article 10: Whether God knows evil things?
Objection 1: It seems that God does not know evil things. For the Philosopher (De Anima iii) says that the intellect which is not in potentiality does not know privation. But "evil is the privation of good," as Augustine says (Confess. iii, 7). Therefore, as the intellect of God is never in potentiality, but is always in act, as is clear from the foregoing (Article ), it seems that God does not know evil things.
Objection 2: Further, all knowledge is either the cause of the thing known,
or is caused by it. But the knowledge of God is not the cause of evil,
nor is it caused by evil. Therefore God does not know evil things.
Objection 3: Further, everything known is known either by its likeness, or by
its opposite. But whatever God knows, He knows through His essence, as is
clear from the foregoing (Article ). Now the divine essence neither is the
likeness of evil, nor is evil contrary to it; for to the divine essence
there is no contrary, as Augustine says (De Civ. Dei xii). Therefore God
does not know evil things.
Objection 4: Further, what is known through another and not through itself, is
imperfectly known. But evil is not known by God; for the thing known must
be in the knower. Therefore if evil is known through another, namely,
through good, it would be known by Him imperfectly; which cannot be, for
the knowledge of God is not imperfect. Therefore God does not know evil
On the contrary, It is written (Prov. 15:11), "Hell and destruction are
before God [Vulg: 'the Lord']."
I answer that, Whoever knows a thing perfectly, must know all that can
be accidental to it. Now there are some good things to which corruption
by evil may be accidental. Hence God would not know good things
perfectly, unless He also knew evil things. Now a thing is knowable in
the degree in which it is; hence since this is the essence of evil that
it is the privation of good, by the fact that God knows good things, He
knows evil things also; as by light is known darkness. Hence Dionysius
says (Div. Nom. vii): "God through Himself receives the vision of
darkness, not otherwise seeing darkness except through light."
Reply to Objection 1: The saying of the Philosopher must be understood as meaning
that the intellect which is not in potentiality, does not know privation
by privation existing in it; and this agrees with what he said
previously, that a point and every indivisible thing are known by
privation of division. This is because simple and indivisible forms are
in our intellect not actually, but only potentially; for were they
actually in our intellect, they would not be known by privation. It is
thus that simple things are known by separate substances. God therefore
knows evil, not by privation existing in Himself, but by the opposite
Reply to Objection 2: The knowledge of God is not the cause of evil; but is the
cause of the good whereby evil is known.
Reply to Objection 3: Although evil is not opposed to the divine essence, which
is not corruptible by evil; it is opposed to the effects of God, which He
knows by His essence; and knowing them, He knows the opposite evils.
Reply to Objection 4: To know a thing by something else only, belongs to
imperfect knowledge, if that thing is of itself knowable; but evil is
not of itself knowable, forasmuch as the very nature of evil means the
privation of good; therefore evil can neither be defined nor known except
Article 11: Whether God knows singular things?
Objection 1: It seems that God does not know singular things. For the divine
intellect is more immaterial than the human intellect. Now the human
intellect by reason of its immateriality does not know singular things;
but as the Philosopher says (De Anima ii), "reason has to do with
universals, sense with singular things." Therefore God does not know
Objection 2: Further, in us those faculties alone know the singular, which
receive the species not abstracted from material conditions. But in God
things are in the highest degree abstracted from all materiality.
Therefore God does not know singular things.
Objection 3: Further, all knowledge comes about through the medium of some
likeness. But the likeness of singular things in so far as they are
singular, does not seem to be in God; for the principle of singularity is
matter, which, since it is in potentiality only, is altogether unlike
God, Who is pure act. Therefore God cannot know singular things.
On the contrary, It is written (Prov. 16:2), "All the ways of a man are
open to His eyes."
I answer that, God knows singular things. For all perfections found in
creatures pre-exist in God in a higher way, as is clear from the
foregoing (Question , Article ). Now to know singular things is part of our
perfection. Hence God must know singular things. Even the Philosopher
considers it incongruous that anything known by us should be unknown to
God; and thus against Empedocles he argues (De Anima i and Metaph. iii)
that God would be most ignorant if He did not know discord. Now the
perfections which are divided among inferior beings, exist simply and
unitedly in God; hence, although by one faculty we know the universal and
immaterial, and by another we know singular and material things,
nevertheless God knows both by His simple intellect.
Now some, wishing to show how this can be, said that God knows singular things by universal causes. For nothing exists in any singular thing, that does not arise from some universal cause. They give the example of an astrologer who knows all the universal movements of the heavens, and can thence foretell all eclipses that are to come. This, however, is not enough; for singular things from universal causes attain to certain forms and powers which, however they may be joined together, are not individualized except by individual matter. Hence he who knows Socrates because he is white, or because he is the son of Sophroniscus, or because of something of that kind, would not know him in so far as he is this particular man. Hence according to the aforesaid mode, God would not know
singular things in their singularity.
On the other hand, others have said that God knows singular things by
the application of universal causes to particular effects. But this will
not hold; forasmuch as no one can apply a thing to another unless he
first knows that thing; hence the said application cannot be the reason
of knowing the particular, for it presupposes the knowledge of singular
Therefore it must be said otherwise, that, since God is the cause of
things by His knowledge, as stated above (Article ), His knowledge extends as
far as His causality extends. Hence as the active power of God extends
not only to forms, which are the source of universality, but also to
matter, as we shall prove further on (Question , Article ), the knowledge of God
must extend to singular things, which are individualized by matter. For
since He knows things other than Himself by His essence, as being the
likeness of things, or as their active principle, His essence must be the
sufficing principle of knowing all things made by Him, not only in the
universal, but also in the singular. The same would apply to the
knowledge of the artificer, if it were productive of the whole thing, and
not only of the form.
Reply to Objection 1: Our intellect abstracts the intelligible species from the
individualizing principles; hence the intelligible species in our
intellect cannot be the likeness of the individual principles; and on
that account our intellect does not know the singular. But the
intelligible species in the divine intellect, which is the essence of
God, is immaterial not by abstraction, but of itself, being the principle
of all the principles which enter into the composition of things, whether
principles of the species or principles of the individual; hence by it
God knows not only universal, but also singular things.
Reply to Objection 2: Although as regards the species in the divine intellect its
being has no material conditions like the images received in the
imagination and sense, yet its power extends to both immaterial and
Reply to Objection 3: Although matter as regards its potentiality recedes from
likeness to God, yet, even in so far as it has being in this wise, it
retains a certain likeness to the divine being.
Article 12: Whether God can know infinite things?
Objection 1: It seems that God cannot know infinite things. For the infinite, as such, is unknown; since the infinite is that which, "to those who measure it, leaves always something more to be measured," as the Philosopher says (Phys. iii). Moreover, Augustine says (De Civ. Dei xii) that "whatever is comprehended by knowledge, is bounded by the comprehension of the knower." Now infinite things have no boundary. Therefore they cannot be comprehended by the knowledge of God.
Objection 2: Further, if we say that things infinite in themselves are finite
in God's knowledge, against this it may be urged that the essence of the
infinite is that it is untraversable, and the finite that it is
traversable, as said in Phys. iii. But the infinite is not traversable
either by the finite or by the infinite, as is proved in Phys. vi.
Therefore the infinite cannot be bounded by the finite, nor even by the
infinite; and so the infinite cannot be finite in God's knowledge, which
Objection 3: Further, the knowledge of God is the measure of what is known.
But it is contrary to the essence of the infinite that it be measured.
Therefore infinite things cannot be known by God.
On the contrary, Augustine says (De Civ. Dei xii), "Although we cannot
number the infinite, nevertheless it can be comprehended by Him whose
knowledge has no bounds."
I answer that, Since God knows not only things actual but also things
possible to Himself or to created things, as shown above (Article ), and as
these must be infinite, it must be held that He knows infinite things.
Although the knowledge of vision which has relation only to things that
are, or will be, or were, is not of infinite things, as some say, for we
do not say that the world is eternal, nor that generation and movement
will go on for ever, so that individuals be infinitely multiplied; yet,
if we consider more attentively, we must hold that God knows infinite
things even by the knowledge of vision. For God knows even the thoughts
and affections of hearts, which will be multiplied to infinity as
rational creatures go on for ever.
The reason of this is to be found in the fact that the knowledge of
every knower is measured by the mode of the form which is the principle
of knowledge. For the sensible image in sense is the likeness of only one
individual thing, and can give the knowledge of only one individual. But
the intelligible species of our intellect is the likeness of the thing as
regards its specific nature, which is participable by infinite
particulars; hence our intellect by the intelligible species of man in a
certain way knows infinite men; not however as distinguished from each
other, but as communicating in the nature of the species; and the reason
is because the intelligible species of our intellect is the likeness of
man not as to the individual principles, but as to the principles of the
species. On the other hand, the divine essence, whereby the divine
intellect understands, is a sufficing likeness of all things that are, or
can be, not only as regards the universal principles, but also as regards
the principles proper to each one, as shown above. Hence it follows that
the knowledge of God extends to infinite things, even as distinct from
Reply to Objection 1: The idea of the infinite pertains to quantity, as the
Philosopher says (Phys. i). But the idea of quantity implies the order of
parts. Therefore to know the infinite according to the mode of the
infinite is to know part after part; and in this way the infinite cannot
be known; for whatever quantity of parts be taken, there will always
remain something else outside. But God does not know the infinite or
infinite things, as if He enumerated part after part; since He knows all
things simultaneously, and not successively, as said above (Article ). Hence
there is nothing to prevent Him from knowing infinite things.
Reply to Objection 2: Transition imports a certain succession of parts; and hence
it is that the infinite cannot be traversed by the finite, nor by the
infinite. But equality suffices for comprehension, because that is said
to be comprehended which has nothing outside the comprehender. Hence it
is not against the idea of the infinite to be comprehended by the
infinite. And so, what is infinite in itself can be called finite to the
knowledge of God as comprehended; but not as if it were traversable.
Reply to Objection 3: The knowledge of God is the measure of things, not
quantitatively, for the infinite is not subject to this kind of measure;
but it is the measure of the essence and truth of things. For everything
has truth of nature according to the degree in which it imitates the
knowledge of God, as the thing made by art agrees with the art. Granted,
however, an actually infinite number of things, for instance, an
infinitude of men, or an infinitude in continuous quantity, as an
infinitude of air, as some of the ancients held; yet it is manifest that
these would have a determinate and finite being, because their being
would be limited to some determinate nature. Hence they would be
measurable as regards the knowledge of God.
Article 13: Whether the knowledge of God is of future contingent things?
Objection 1: It seems that the knowledge of God is not of future contingent
things. For from a necessary cause proceeds a necessary effect. But the
knowledge of God is the cause of things known, as said above (Article ).
Since therefore that knowledge is necessary, what He knows must also be
necessary. Therefore the knowledge of God is not of contingent things.
Objection 2: Further, every conditional proposition of which the antecedent is
absolutely necessary must have an absolutely necessary consequent. For
the antecedent is to the consequent as principles are to the conclusion:
and from necessary principles only a necessary conclusion can follow, as
is proved in Poster. i. But this is a true conditional proposition, "If
God knew that this thing will be, it will be," for the knowledge of God
is only of true things. Now the antecedent conditional of this is
absolutely necessary, because it is eternal, and because it is signified
as past. Therefore the consequent is also absolutely necessary. Therefore
whatever God knows, is necessary; and so the knowledge of God is not of
Objection 3: Further, everything known by God must necessarily be, because
even what we ourselves know, must necessarily be; and, of course, the
knowledge of God is much more certain than ours. But no future contingent
things must necessarily be. Therefore no contingent future thing is known
On the contrary, It is written (Ps. 32:15), "He Who hath made the hearts
of every one of them; Who understandeth all their works," i.e. of men.
Now the works of men are contingent, being subject to free will.
Therefore God knows future contingent things.
I answer that, Since as was shown above (Article ), God knows all things;
not only things actual but also things possible to Him and creature; and
since some of these are future contingent to us, it follows that God
knows future contingent things.
In evidence of this, we must consider that a contingent thing can be
considered in two ways; first, in itself, in so far as it is now in act:
and in this sense it is not considered as future, but as present; neither
is it considered as contingent (as having reference) to one of two terms,
but as determined to one; and on account of this it can be infallibly the
object of certain knowledge, for instance to the sense of sight, as when
I see that Socrates is sitting down. In another way a contingent thing
can be considered as it is in its cause; and in this way it is considered
as future, and as a contingent thing not yet determined to one; forasmuch
as a contingent cause has relation to opposite things: and in this sense
a contingent thing is not subject to any certain knowledge. Hence,
whoever knows a contingent effect in its cause only, has merely a
conjectural knowledge of it. Now God knows all contingent things not only
as they are in their causes, but also as each one of them is actually in
itself. And although contingent things become actual successively,
nevertheless God knows contingent things not successively, as they are in
their own being, as we do but simultaneously. The reason is because His
knowledge is measured by eternity, as is also His being; and eternity
being simultaneously whole comprises all time, as said above (Question , Article ). Hence all things that are in time are present to God from eternity,
not only because He has the types of things present within Him, as some
say; but because His glance is carried from eternity over all things as
they are in their presentiality. Hence it is manifest that contingent
things are infallibly known by God, inasmuch as they are subject to the
divine sight in their presentiality; yet they are future contingent
things in relation to their own causes.
Reply to Objection 1: Although the supreme cause is necessary, the effect may be
contingent by reason of the proximate contingent cause; just as the
germination of a plant is contingent by reason of the proximate
contingent cause, although the movement of the sun which is the first
cause, is necessary. So likewise things known by God are contingent on
account of their proximate causes, while the knowledge of God, which is
the first cause, is necessary.
Reply to Objection 2: Some say that this antecedent, "God knew this contingent to
be future," is not necessary, but contingent; because, although it is
past, still it imports relation to the future. This however does not
remove necessity from it; for whatever has had relation to the future,
must have had it, although the future sometimes does not follow. On the
other hand some say that this antecedent is contingent, because it is a
compound of necessary and contingent; as this saying is contingent,
"Socrates is a white man." But this also is to no purpose; for when we
say, "God knew this contingent to be future," contingent is used here
only as the matter of the word, and not as the chief part of the
proposition. Hence its contingency or necessity has no reference to the
necessity or contingency of the proposition, or to its being true or
false. For it may be just as true that I said a man is an ass, as that I
said Socrates runs, or God is: and the same applies to necessary and
contingent. Hence it must be said that this antecedent is absolutely
necessary. Nor does it follow, as some say, that the consequent is
absolutely necessary, because the antecedent is the remote cause of the
consequent, which is contingent by reason of the proximate cause. But
this is to no purpose. For the conditional would be false were its
antecedent the remote necessary cause, and the consequent a contingent
effect; as, for example, if I said, "if the sun moves, the grass will
Therefore we must reply otherwise; that when the antecedent contains
anything belonging to an act of the soul, the consequent must be taken
not as it is in itself, but as it is in the soul: for the existence of a
thing in itself is different from the existence of a thing in the soul.
For example, when I say, "What the soul understands is immaterial," this
is to be understood that it is immaterial as it is in the intellect, not
as it is in itself. Likewise if I say, "If God knew anything, it will
be," the consequent must be understood as it is subject to the divine
knowledge, i.e. as it is in its presentiality. And thus it is necessary,
as also is the antecedent: "For everything that is, while it is, must be
necessarily be," as the Philosopher says in Peri Herm. i.
Reply to Objection 3: Things reduced to act in time, as known by us successively in time, but by God (are known) in eternity, which is above time. Whence to us they cannot be certain, forasmuch as we know future contingent things as such; but (they are certain) to God alone, whose understanding is in eternity above time. Just as he who goes along the road, does not see those who come after him; whereas he who sees the whole road from a height, sees at once all travelling by the way. Hence what is known by us must be necessary, even as it is in itself; for what is future contingent in itself, cannot be known by us. Whereas what is known by God must be necessary according to the mode in which they are subject to the divine knowledge, as already stated, but not absolutely as considered in their own causes. Hence also this proposition, "Everything known by God must necessarily be," is usually distinguished; for this may refer to the thing, or to the saying. If it refers to the thing, it is divided and false; for the sense is, "Everything which God knows is necessary." If understood of the saying, it is composite and true; for the sense is, "This proposition, 'that which is known by God is' is necessary."
Now some urge an objection and say that this distinction holds good with
regard to forms that are separable from the subject; thus if I said, "It
is possible for a white thing to be black," it is false as applied to the
saying, and true as applied to the thing: for a thing which is white, can
become black; whereas this saying, " a white thing is black" can never be
true. But in forms that are inseparable from the subject, this
distinction does not hold, for instance, if I said, "A black crow can be
white"; for in both senses it is false. Now to be known by God is
inseparable from the thing; for what is known by God cannot be known.
This objection, however, would hold if these words "that which is known"
implied any disposition inherent to the subject; but since they import an
act of the knower, something can be attributed to the thing known, in
itself (even if it always be known), which is not attributed to it in so
far as it stands under actual knowledge; thus material existence is
attributed to a stone in itself, which is not attributed to it inasmuch
as it is known.
Article 14: Whether God knows enunciable things?
Objection 1: It seems that God does not know enunciable things. For to know
enunciable things belongs to our intellect as it composes and divides.
But in the divine intellect, there is no composition. Therefore God does
not know enunciable things.
Objection 2: Further, every kind of knowledge is made through some likeness.
But in God there is no likeness of enunciable things, since He is
altogether simple. Therefore God does not know enunciable things.
On the contrary, It is written: "The Lord knoweth the thoughts of men"
(Ps. 93:11). But enunciable things are contained in the thoughts of men.
Therefore God knows enunciable things.
I answer that, Since it is in the power of our intellect to form
enunciations, and since God knows whatever is in His own power or in that
of creatures, as said above (Article ), it follows of necessity that God
knows all enunciations that can be formed.
Now just as He knows material things immaterially, and composite things
simply, so likewise He knows enunciable things not after the manner of
enunciable things, as if in His intellect there were composition or
division of enunciations; for He knows each thing by simple intelligence,
by understanding the essence of each thing; as if we by the very fact
that we understand what man is, were to understand all that can be
predicated of man. This, however, does not happen in our intellect, which
discourses from one thing to another, forasmuch as the intelligible
species represents one thing in such a way as not to represent another.
Hence when we understand what man is, we do not forthwith understand
other things which belong to him, but we understand them one by one,
according to a certain succession. On this account the things we
understand as separated, we must reduce to one by way of composition or
division, by forming an enunciation. Now the species of the divine
intellect, which is God's essence, suffices to represent all things.
Hence by understanding His essence, God knows the essences of all things,
and also whatever can be accidental to them.
Reply to Objection 1: This objection would avail if God knew enunciable things
after the manner of enunciable things.
Reply to Objection 2: Enunciatory composition signifies some existence of a
thing; and thus God by His existence, which is His essence, is the
similitude of all those things which are signified by enunciation.
Article 15: Whether the knowledge of God is variable?
Objection 1: It seems that the knowledge of God is variable. For knowledge is
related to what is knowable. But whatever imports relation to the
creature is applied to God from time, and varies according to the
variation of creatures. Therefore the knowledge of God is variable
according to the variation of creatures.
Objection 2: Further, whatever God can make, He can know. But God can make
more than He does. Therefore He can know more than He knows. Thus His
knowledge can vary according to increase and diminution.
Objection 3: Further, God knew that Christ would be born. But He does not know
now that Christ will be born; because Christ is not to be born in the
future. Therefore God does not know everything He once knew; and thus the
knowledge of God is variable.
On the contrary, It is said, that in God "there is no change nor shadow
of alteration" (James 1:17).
I answer that, Since the knowledge of God is His substance, as is clear
from the foregoing (Article ), just as His substance is altogether immutable,
as shown above (Question , Article ), so His knowledge likewise must be altogether
Reply to Objection 1: "Lord", "Creator" and the like, import relations to
creatures in so far as they are in themselves. But the knowledge of God
imports relation to creatures in so far as they are in God; because
everything is actually understood according as it is in the one who
understands. Now created things are in God in an invariable manner; while
they exist variably in themselves. We may also say that "Lord", "Creator"
and the like, import the relations consequent upon the acts which are
understood as terminating in the creatures themselves, as they are in
themselves; and thus these relations are attributed to God variously,
according to the variation of creatures. But "knowledge" and "love," and
the like, import relations consequent upon the acts which are understood
to be in God; and therefore these are predicated of God in an invariable
Reply to Objection 2: God knows also what He can make, and does not make. Hence
from the fact that He can make more than He makes, it does not follow
that He can know more than He knows, unless this be referred to the
knowledge of vision, according to which He is said to know those things
which are in act in some period of time. But from the fact that He knows
some things might be which are not, or that some things might not be
which are, it does not follow that His knowledge is variable, but rather
that He knows the variability of things. If, however, anything existed
which God did not previously know, and afterwards knew, then His
knowledge would be variable. But this could not be; for whatever is, or
can be in any period of time, is known by God in His eternity. Therefore
from the fact that a thing exists in some period of time, it follows that
it is known by God from eternity. Therefore it cannot be granted that God
can know more than He knows; because such a proposition implies that
first of all He did not know, and then afterwards knew.
Reply to Objection 3: The ancient Nominalists said that it was the same thing to
say "Christ is born" and "will be born" and "was born"; because the same
thing is signified by these three---viz. the nativity of Christ.
Therefore it follows, they said, that whatever God knew, He knows;
because now He knows that Christ is born, which means the same thing as
that Christ will be born. This opinion, however, is false; both because
the diversity in the parts of a sentence causes a diversity of
enunciations; and because it would follow that a proposition which is
true once would be always true; which is contrary to what the Philosopher
lays down (Categor. iii) when he says that this sentence, "Socrates
sits," is true when he is sitting, and false when he rises up. Therefore,
it must be conceded that this proposition is not true, "Whatever God knew
He knows," if referred to enunciable propositions. But because of this,
it does not follow that the knowledge of God is variable. For as it is
without variation in the divine knowledge that God knows one and the same
thing sometime to be, and sometime not to be, so it is without variation
in the divine knowledge that God knows an enunciable proposition is
sometime true, and sometime false. The knowledge of God, however, would
be variable if He knew enunciable things by way of enunciation, by
composition and division, as occurs in our intellect. Hence our knowledge
varies either as regards truth and falsity, for example, if when either
as regards truth and falsity, for example, if when a thing suffers change
we retained the same opinion about it; or as regards diverse opinions, as
if we first thought that anyone was sitting, and afterwards thought that
he was not sitting; neither of which can be in God.
Article 16: Whether God has a speculative knowledge of things?
Objection 1: It seems that God has not a speculative knowledge of things. For
the knowledge of God is the cause of things, as shown above (Article ). But
speculative knowledge is not the cause of the things known. Therefore
the knowledge of God is not speculative.
Objection 2: Further, speculative knowledge comes by abstraction from things;
which does not belong to the divine knowledge. Therefore the knowledge of
God is not speculative.
On the contrary, Whatever is the more excellent must be attributed to
God. But speculative knowledge is more excellent than practical
knowledge, as the Philosopher says in the beginning of Metaphysics.
Therefore God has a speculative knowledge of things.
I answer that, Some knowledge is speculative only; some is practical
only; and some is partly speculative and partly practical. In proof
whereof it must be observed that knowledge can be called speculative in
three ways: first, on the part of the things known, which are not
operable by the knower; such is the knowledge of man about natural or
divine thing. Secondly, as regards the manner of knowing---as, for
instance, if a builder consider a house by defining and dividing, and
considering what belongs to it in general: for this is to consider
operable things in a speculative manner, and not as practically operable;
for operable means the application of form to matter, and not the
resolution of the composite into its universal formal principles.
Thirdly, as regards the end; "for the practical intellect differs in its
end from the speculative," as the Philosopher says (De Anima iii). For
the practical intellect is ordered to the end of the operation; whereas
the end of the speculative intellect is the consideration of truth. Hence
if a builder should consider how a house can be made, not ordering this
to the end of operation, but only to know (how to do it), this would be
only a speculative considerations as regards the end, although it
concerns an operable thing. Therefore knowledge which is speculative by
reason of the thing itself known, is merely speculative. But that which
is speculative either in its mode or as to its end is partly speculative
and partly practical: and when it is ordained to an operative end it is
In accordance with this, therefore, it must be said that God has of
Himself a speculative knowledge only; for He Himself is not operable. But
of all other things He has both speculative and practical knowledge. He
has speculative knowledge as regards the mode; for whatever we know
speculatively in things by defining and dividing, God knows all this much
Now of things which He can make, but does not make at any time, He has
not a practical knowledge, according as knowledge is called practical
from the end. But He has a practical knowledge of what He makes in some
period of time. And, as regards evil things, although they are not
operable by Him, yet they fall under His practical knowledge, like good
things, inasmuch as He permits, or impedes, or directs them; as also
sicknesses fall under the practical knowledge of the physician, inasmuch
as he cures them by his art.
Reply to Objection 1: The knowledge of God is the cause, not indeed of Himself,
but of other things. He is actually the cause of some, that is, of things
that come to be in some period of time; and He is virtually the cause of
others, that is, of things which He can make, and which nevertheless are
Reply to Objection 2: The fact that knowledge is derived from things known does
not essentially belong to speculative knowledge, but only accidentally in
so far as it is human.
In answer to what is objected on the contrary, we must say that perfect
knowledge of operable things is obtainable only if they are known in so
far as they are operable. Therefore, since the knowledge of God is in
every way perfect, He must know what is operable by Him, formally as
such, and not only in so far as they are speculative. Nevertheless this
does not impair the nobility of His speculative knowledge, forasmuch as
He sees all things other than Himself in Himself, and He knows Himself
speculatively; and so in the speculative knowledge of Himself, he
possesses both speculative and practical knowledge of all other things.