Summa Th. I EN Qu.5 a.3

Whether every being is good?

Objection: 1. It seems that not every being is good. For goodness is something superadded to being, as is clear from Article [1]. But whatever is added to being limits it; as substance, quantity, quality, etc. Therefore goodness limits being. Therefore not every being is good.

2. Further, no evil is good: "Woe to you that call evil good and good evil" (Is 5,20). But some things are called evil. Therefore not every being is good.

3. Further, goodness implies desirability. Now primary matter does not imply desirability, but rather that which desires. Therefore primary matter does not contain the formality of goodness. Therefore not every being is good.

4. Further, the Philosopher notes (Metaph. iii) that "in mathematics goodness does not exist." But mathematics are entities; otherwise there would be no science of mathematics. Therefore not every being is good.

On the contrary Every being that is not God is God's creature. Now every creature of God is good (1Tm 4,4): and God is the greatest good. Therefore every being is good.

I answer that Every being, as being, is good. For all being, as being, has actuality and is in some way perfect; since every act implies some sort of perfection; and perfection implies desirability and goodness, as is clear from Article [1]. Hence it follows that every being as such is good.

Reply to Objection: 1. Substance, quantity, quality, and everything included in them, limit being by applying it to some essence or nature. Now in this sense, goodness does not add anything to being beyond the aspect of desirability and perfection, which is also proper to being, whatever kind of nature it may be. Hence goodness does not limit being.

2. No being can be spoken of as evil, formally as being, but only so far as it lacks being. Thus a man is said to be evil, because he lacks some virtue; and an eye is said to be evil, because it lacks the power to see well.

3. As primary matter has only potential being, so it is only potentially good. Although, according to the Platonists, primary matter may be said to be a non-being on account of the privation attaching to it, nevertheless, it does participate to a certain extent in goodness, viz. by its relation to, or aptitude for, goodness. Consequently, to be desirable is not its property, but to desire.

4. Mathematical entities do not subsist as realities; because they would be in some sort good if they subsisted; but they have only logical existence, inasmuch as they are abstracted from motion and matter; thus they cannot have the aspect of an end, which itself has the aspect of moving another. Nor is it repugnant that there should be in some logical entity neither goodness nor form of goodness; since the idea of being is prior to the idea of goodness, as was said in the preceding article.

Whether goodness has the aspect of a final cause?

Objection: 1. It seems that goodness has not the aspect of a final cause, but rather of the other causes. For, as Dionysius says (Div. Nom. iv), "Goodness is praised as beauty." But beauty has the aspect of a formal cause. Therefore goodness has the aspect of a formal cause.

2. Further, goodness is self-diffusive; for Dionysius says (Div. Nom. iv) that goodness is that whereby all things subsist, and are. But to be self-giving implies the aspect of an efficient cause. Therefore goodness has the aspect of an efficient cause.

3. Further, Augustine says (De Doctr. Christ. i, 31) that "we exist because God is good." But we owe our existence to God as the efficient cause. Therefore goodness implies the aspect of an efficient cause.

On the contrary The Philosopher says (Phys. ii) that "that is to be considered as the end and the good of other things, for the sake of which something is." Therefore goodness has the aspect of a final cause.

I answer that Since goodness is that which all things desire, and since this has the aspect of an end, it is clear that goodness implies the aspect of an end. Nevertheless, the idea of goodness presupposes the idea of an efficient cause, and also of a formal cause. For we see that what is first in causing, is last in the thing caused. Fire, e.g. heats first of all before it reproduces the form of fire; though the heat in the fire follows from its substantial form. Now in causing, goodness and the end come first, both of which move the agent to act; secondly, the action of the agent moving to the form; thirdly, comes the form. Hence in that which is caused the converse ought to take place, so that there should be first, the form whereby it is a being; secondly, we consider in it its effective power, whereby it is perfect in being, for a thing is perfect when it can reproduce its like, as the Philosopher says (Meteor. iv); thirdly, there follows the formality of goodness which is the basic principle of its perfection.

Reply to Objection: 1. Beauty and goodness in a thing are identical fundamentally; for they are based upon the same thing, namely, the form; and consequently goodness is praised as beauty. But they differ logically, for goodness properly relates to the appetite (goodness being what all things desire); and therefore it has the aspect of an end (the appetite being a kind of movement towards a thing). On the other hand, beauty relates to the cognitive faculty; for beautiful things are those which please when seen. Hence beauty consists in due proportion; for the senses delight in things duly proportioned, as in what is after their own kind---because even sense is a sort of reason, just as is every cognitive faculty. Now since knowledge is by assimilation, and similarity relates to form, beauty properly belongs to the nature of a formal cause.

2. Goodness is described as self-diffusive in the sense that an end is said to move.

3. He who has a will is said to be good, so far as he has a good will; because it is by our will that we employ whatever powers we may have. Hence a man is said to be good, not by his good understanding; but by his good will. Now the will relates to the end as to its proper object. Thus the saying, "we exist because God is good" has reference to the final cause.

Whether the essence of goodness consists in mode, species and order?

Objection: 1. It seems that the essence of goodness does not consist in mode, species and order. For goodness and being differ logically. But mode, species and order seem to belong to the nature of being, for it is written: "Thou hast ordered all things in measure, and number, and weight" (Sg 11,21). And to these three can be reduced species, mode and order, as Augustine says (Gn ad lit. iv, 3): "Measure fixes the mode of everything, number gives it its species, and weight gives it rest and stability." Therefore the essence of goodness does not consist in mode, species and order.

2. Further, mode, species and order are themselves good. Therefore if the essence of goodness consists in mode, species and order, then every mode must have its own mode, species and order. The same would be the case with species and order in endless succession.

3. Further, evil is the privation of mode, species and order. But evil is not the total absence of goodness. Therefore the essence of goodness does not consist in mode, species and order.

4. Further, that wherein consists the essence of goodness cannot be spoken of as evil. Yet we can speak of an evil mode, species and order. Therefore the essence of goodness does not consist in mode, species and order.

5. Further, mode, species and order are caused by weight, number and measure, as appears from the quotation from Augustine. But not every good thing has weight, number and measure; for Ambrose says (Hexam. i, 9): "It is of the nature of light not to have been created in number, weight and measure." Therefore the essence of goodness does not consist in mode, species and order.

On the contrary Augustine says (De Nat. Boni. iii): "These three---mode, species and order---as common good things, are in everything God has made; thus, where these three abound the things are very good; where they are less, the things are less good; where they do not exist at all, there can be nothing good." But this would not be unless the essence of goodness consisted in them. Therefore the essence of goodness consists in mode, species and order.

I answer that Everything is said to be good so far as it is perfect; for in that way only is it desirable (as shown above Articles [1],3). Now a thing is said to be perfect if it lacks nothing according to the mode of its perfection. But since everything is what it is by its form (and since the form presupposes certain things, and from the form certain things necessarily follow), in order for a thing to be perfect and good it must have a form, together with all that precedes and follows upon that form. Now the form presupposes determination or commensuration of its principles, whether material or efficient, and this is signified by the mode: hence it is said that the measure marks the mode. But the form itself is signified by the species; for everything is placed in its species by its form. Hence the number is said to give the species, for definitions signifying species are like numbers, according to the Philosopher (Metaph. x); for as a unit added to, or taken from a number, changes its species, so a difference added to, or taken from a definition, changes its species. Further, upon the form follows an inclination to the end, or to an action, or something of the sort; for everything, in so far as it is in act, acts and tends towards that which is in accordance with its form; and this belongs to weight and order. Hence the essence of goodness, so far as it consists in perfection, consists also in mode, species and order.

Reply to Objection: 1. These three only follow upon being, so far as it is perfect, and according to this perfection is it good.

2. Mode, species and order are said to be good, and to be beings, not as though they themselves were subsistences, but because it is through them that other things are both beings and good. Hence they have no need of other things whereby they are good: for they are spoken of as good, not as though formally constituted so by something else, but as formally constituting others good: thus whiteness is not said to be a being as though it were by anything else; but because, by it, something else has accidental being, as an object that is white.

3. Every being is due to some form. Hence, according to every being of a thing is its mode, species, order. Thus, a man has a mode, species and order as he is white, virtuous, learned and so on; according to everything predicated of him. But evil deprives a thing of some sort of being, as blindness deprives us of that being which is sight; yet it does not destroy every mode, species and order, but only such as follow upon the being of sight.

4. Augustine says (De Nat. Boni. xxiii), "Every mode, as mode, is good" (and the same can be said of species and order). "But an evil mode, species and order are so called as being less than they ought to be, or as not belonging to that which they ought to belong. Therefore they are called evil, because they are out of place and incongruous."

5. The nature of light is spoken of as being without number, weight and measure, not absolutely, but in comparison with corporeal things, because the power of light extends to all corporeal things; inasmuch as it is an active quality of the first body that causes change, i.e. the heavens.

Whether goodness is rightly divided into the virtuous*, the useful and the pleasant?

[*"Bonum honestum" is the virtuous good considered as fitting. (cf. SS, Question [141], Article [3]; SS, Question [145])]

Objection: 1. It seems that goodness is not rightly divided into the virtuous, the useful and the pleasant. For goodness is divided by the ten predicaments, as the Philosopher says (Ethic. i). But the virtuous, the useful and the pleasant can be found under one predicament. Therefore goodness is not rightly divided by them.

2. Further, every division is made by opposites. But these three do not seem to be opposites; for the virtuous is pleasing, and no wickedness is useful; whereas this ought to be the case if the division were made by opposites, for then the virtuous and the useful would be opposed; and Tully speaks of this (De Offic. ii). Therefore this division is incorrect.

3. Further, where one thing is on account of another, there is only one thing. But the useful is not goodness, except so far as it is pleasing and virtuous. Therefore the useful ought not to divided against the pleasant and the virtuous.

On the contrary Ambrose makes use of this division of goodness (De Offic. i, 9)

I answer that This division properly concerns human goodness. But if we consider the nature of goodness from a higher and more universal point of view, we shall find that this division properly concerns goodness as such. For everything is good so far as it is desirable, and is a term of the movement of the appetite; the term of whose movement can be seen from a consideration of the movement of a natural body. Now the movement of a natural body is terminated by the end absolutely; and relatively by the means through which it comes to the end, where the movement ceases; so a thing is called a term of movement, so far as it terminates any part of that movement. Now the ultimate term of movement can be taken in two ways, either as the thing itself towards which it tends, e.g. a place or form; or a state of rest in that thing. Thus, in the movement of the appetite, the thing desired that terminates the movement of the appetite relatively, as a means by which something tends towards another, is called the useful; but that sought after as the last thing absolutely terminating the movement of the appetite, as a thing towards which for its own sake the appetite tends, is called the virtuous; for the virtuous is that which is desired for its own sake; but that which terminates the movement of the appetite in the form of rest in the thing desired, is called the pleasant.

Reply to Objection: 1. Goodness, so far as it is identical with being, is divided by the ten predicaments. But this division belongs to it according to its proper formality.

2. This division is not by opposite things; but by opposite aspects. Now those things are called pleasing which have no other formality under which they are desirable except the pleasant, being sometimes hurtful and contrary to virtue. Whereas the useful applies to such as have nothing desirable in themselves, but are desired only as helpful to something further, as the taking of bitter medicine; while the virtuous is predicated of such as are desirable in themselves.
3. Goodness is not divided into these three as something univocal to be predicated equally of them all; but as something analogical to be predicated of them according to priority and posteriority. Hence it is predicated chiefly of the virtuous; then of the pleasant; and lastly of the useful.



We next consider the goodness of God; under which head there are four points of inquiry:

(1) Whether goodness belongs to God?

(2) Whether God is the supreme good?

(3) Whether He alone is essentially good?

(4) Whether all things are good by the divine goodness?

Whether God is good?

Objection: 1. It seems that to be good does not belong to God. For goodness consists in mode, species and order. But these do not seem to belong to God; since God is immense and is not ordered to anything else. Therefore to be good does not belong to God.

2. Further, the good is what all things desire. But all things do not desire God, because all things do not know Him; and nothing is desired unless it is known. Therefore to be good does not belong to God.

On the contrary It is written (Lm 3,25): "The Lord is good to them that hope in Him, to the soul that seeketh Him."

I answer that To be good belongs pre-eminently to God. For a thing is good according to its desirableness. Now everything seeks after its own perfection; and the perfection and form of an effect consist in a certain likeness to the agent, since every agent makes its like; and hence the agent itself is desirable and has the nature of good. For the very thing which is desirable in it is the participation of its likeness. Therefore, since God is the first effective cause of all things, it is manifest that the aspect of good and of desirableness belong to Him; and hence Dionysius (Div. Nom. iv) attributes good to God as to the first efficient cause, saying that, God is called good "as by Whom all things subsist."

Reply to Objection: 1. To have mode, species and order belongs to the essence of caused good; but good is in God as in its cause, and hence it belongs to Him to impose mode, species and order on others; wherefore these three things are in God as in their cause.

2. All things, by desiring their own perfection, desire God Himself, inasmuch as the perfections of all things are so many similitudes of the divine being; as appears from what is said above (Question [4], Article [3]). And so of those things which desire God, some know Him as He is Himself, and this is proper to the rational creature; others know some participation of His goodness, and this belongs also to sensible knowledge; others have a natural desire without knowledge, as being directed to their ends by a higher intelligence.

Whether God is the supreme good?

Objection: 1. It seems that God is not the supreme good. For the supreme good adds something to good; otherwise it would belong to every good. But everything which is an addition to anything else is a compound thing: therefore the supreme good is a compound. But God is supremely simple; as was shown above (Question [3], Article [7]). Therefore God is not the supreme good.

2. Further, "Good is what all desire," as the Philosopher says (Ethic. i, 1). Now what all desire is nothing but God, Who is the end of all things: therefore there is no other good but God. This appears also from what is said (Lc 18,19): "None is good but God alone." But we use the word supreme in comparison with others, as e.g. supreme heat is used in comparison with all other heats. Therefore God cannot be called the supreme good.

3. Further, supreme implies comparison. But things not in the same genus are not comparable; as, sweetness is not properly greater or less than a line. Therefore, since God is not in the same genus as other good things, as appears above (Question [3], Article [5]; Question [4], Article [3]) it seems that God cannot be called the supreme good in relation to others.

On the contrary Augustine says (De Trin. ii) that, the Trinity of the divine persons is "the supreme good, discerned by purified minds."

I answer that God is the supreme good simply, and not only as existing in any genus or order of things. For good is attributed to God, as was said in the preceding article, inasmuch as all desired perfections flow from Him as from the first cause. They do not, however, flow from Him as from a univocal agent, as shown above (Question [4], Article [2]); but as from an agent which does not agree with its effects either in species or genus. Now the likeness of an effect in the univocal cause is found uniformly; but in the equivocal cause it is found more excellently, as, heat is in the sun more excellently than it is in fire. Therefore as good is in God as in the first, but not the univocal, cause of all things, it must be in Him in a most excellent way; and therefore He is called the supreme good.

Reply to Objection: 1. The supreme good does not add to good any absolute thing, but only a relation. Now a relation of God to creatures, is not a reality in God, but in the creature; for it is in God in our idea only: as, what is knowable is so called with relation to knowledge, not that it depends on knowledge, but because knowledge depends on it. Thus it is not necessary that there should be composition in the supreme good, but only that other things are deficient in comparison with it.

2. When we say that good is what all desire, it is not to be understood that every kind of good thing is desired by all; but that whatever is desired has the nature of good. And when it is said, "None is good but God alone," this is to be understood of essential goodness, as will be explained in the next article.

3. Things not of the same genus are in no way comparable to each other if indeed they are in different genera. Now we say that God is not in the same genus with other good things; not that He is any other genus, but that He is outside genus, and is the principle of every genus; and thus He is compared to others by excess, and it is this kind of comparison the supreme good implies.

Whether to be essentially good belongs to God alone?

Objection: 1. It seems that to be essentially good does not belong to God alone. For as "one" is convertible with "being," so is "good"; as we said above (Question [5], Article [1]). But every being is one essentially, as appears from the Philosopher (Metaph. iv); therefore every being is good essentially.

2. Further, if good is what all things desire, since being itself is desired by all, then the being of each thing is its good. But everything is a being essentially; therefore every being is good essentially.

3. Further, everything is good by its own goodness. Therefore if there is anything which is not good essentially, it is necessary to say that its goodness is not its own essence. Therefore its goodness, since it is a being, must be good; and if it is good by some other goodness, the same question applies to that goodness also; therefore we must either proceed to infinity, or come to some goodness which is not good by any other goodness. Therefore the first supposition holds good. Therefore everything is good essentially.

On the contrary Boethius says (De Hebdom.), that "all things but God are good by participation." Therefore they are not good essentially.

I answer that God alone is good essentially. For everything is called good according to its perfection. Now perfection of a thing is threefold: first, according to the constitution of its own being; secondly, in respect of any accidents being added as necessary for its perfect operation; thirdly, perfection consists in the attaining to something else as the end. Thus, for instance, the first perfection of fire consists in its existence, which it has through its own substantial form; its secondary perfection consists in heat, lightness and dryness, and the like; its third perfection is to rest in its own place. This triple perfection belongs to no creature by its own essence; it belongs to God only, in Whom alone essence is existence; in Whom there are no accidents; since whatever belongs to others accidentally belongs to Him essentially; as, to be powerful, wise and the like, as appears from what is stated above (Question [3], Article [6]); and He is not directed to anything else as to an end, but is Himself the last end of all things. Hence it is manifest that God alone has every kind of perfection by His own essence; therefore He Himself alone is good essentially.

Reply to Objection: 1. "One" does not include the idea of perfection, but only of indivision, which belongs to everything according to its own essence. Now the essences of simple things are undivided both actually and potentially, but the essences of compounds are undivided only actually; and therefore everything must be one essentially, but not good essentially, as was shown above.

2. Although everything is good in that it has being, yet the essence of a creature is not very being; and therefore it does not follow that a creature is good essentially.

3. The goodness of a creature is not its very essence, but something superadded; it is either its existence, or some added perfection, or the order to its end. Still, the goodness itself thus added is good, just as it is being. But for this reason is it called being because by it something has being, not because it itself has being through something else: hence for this reason is it called good because by it something is good, and not because it itself has some other goodness whereby it is good.

Whether all things are good by the divine goodness?

Objection: 1. It seems that all things are good by the divine goodness. For Augustine says (De Trin. viii), "This and that are good; take away this and that, and see good itself if thou canst; and so thou shalt see God, good not by any other good, but the good of every good." But everything is good by its own good; therefore everything is good by that very good which is God.

2. Further, as Boethius says (De Hebdom.), all things are called good, accordingly as they are directed to God, and this is by reason of the divine goodness; therefore all things are good by the divine goodness.

On the contrary All things are good, inasmuch as they have being. But they are not called beings through the divine being, but through their own being; therefore all things are not good by the divine goodness, but by their own goodness.

I answer that As regards relative things, we must admit extrinsic denomination; as, a thing is denominated "placed" from "place," and "measured" from "measure." But as regards absolute things opinions differ. Plato held the existence of separate ideas (Question [84], Article [4]) of all things, and that individuals were denominated by them as participating in the separate ideas; for instance, that Socrates is called man according to the separate idea of man. Now just as he laid down separate ideas of man and horse which he called absolute man and absolute horse, so likewise he laid down separate ideas of "being" and of "one," and these he called absolute being and absolute oneness; and by participation of these, everything was called "being" or "one"; and what was thus absolute being and absolute one, he said was the supreme good. And because good is convertible with being, as one is also; he called God the absolute good, from whom all things are called good by way of participation.

Although this opinion appears to be unreasonable in affirming separate ideas of natural things as subsisting of themselves---as Aristotle argues in many ways---still, it is absolutely true that there is first something which is essentially being and essentially good, which we call God, as appears from what is shown above (Question [2], Article [3]), and Aristotle agrees with this. Hence from the first being, essentially such, and good, everything can be called good and a being, inasmuch as it participates in it by way of a certain assimilation which is far removed and defective; as appears from the above (Question [4], Article [3]).

Everything is therefore called good from the divine goodness, as from the first exemplary effective and final principle of all goodness. Nevertheless, everything is called good by reason of the similitude of the divine goodness belonging to it, which is formally its own goodness, whereby it is denominated good. And so of all things there is one goodness, and yet many goodnesses.

This is a sufficient Reply to the Objections.


After considering the divine perfection we must consider the divine infinity, and God's existence in things: for God is everywhere, and in all things, inasmuch as He is boundless and infinite.

Concerning the first, there are four points of inquiry:

(1) Whether God is infinite?

(2) Whether anything besides Him is infinite in essence?

(3) Whether anything can be infinitude in magnitude?

(4) Whether an infinite multitude can exist?

Whether God is infinite?

Objection: 1. It seems that God is not infinite. For everything infinite is imperfect, as the Philosopher says; because it has parts and matter, as is said in Phys. iii. But God is most perfect; therefore He is not infinite.

2. Further, according to the Philosopher (Phys. i), finite and infinite belong to quantity. But there is no quantity in God, for He is not a body, as was shown above (Question [3], Article [1]). Therefore it does not belong to Him to be infinite.

3. Further, what is here in such a way as not to be elsewhere, is finite according to place. Therefore that which is a thing in such a way as not to be another thing, is finite according to substance. But God is this, and not another; for He is not a stone or wood. Therefore God is not infinite in substance.

On the contrary Damascene says (De Fide Orth. i, 4) that "God is infinite and eternal, and boundless."

I answer that All the ancient philosophers attribute infinitude to the first principle, as is said (Phys. iii), and with reason; for they considered that things flow forth infinitely from the first principle. But because some erred concerning the nature of the first principle, as a consequence they erred also concerning its infinity; forasmuch as they asserted that matter was the first principle; consequently they attributed to the first principle a material infinity to the effect that some infinite body was the first principle of things.

We must consider therefore that a thing is called infinite because it is not finite. Now matter is in a way made finite by form, and the form by matter. Matter indeed is made finite by form, inasmuch as matter, before it receives its form, is in potentiality to many forms; but on receiving a form, it is terminated by that one. Again, form is made finite by matter, inasmuch as form, considered in itself, is common to many; but when received in matter, the form is determined to this one particular thing. Now matter is perfected by the form by which it is made finite; therefore infinite as attributed to matter, has the nature of something imperfect; for it is as it were formless matter. On the other hand, form is not made perfect by matter, but rather is contracted by matter; and hence the infinite, regarded on the part of the form not determined by matter, has the nature of something perfect. Now being is the most formal of all things, as appears from what is shown above (Question [4], Article [1], Objection [3]). Since therefore the divine being is not a being received in anything, but He is His own subsistent being as was shown above (Question [3], Article [4]), it is clear that God Himself is infinite and perfect.

Reply to Objection: 1. From this appears the Reply to the First Objection.
2. Quantity is terminated by its form, which can be seen in the fact that a figure which consists in quantity terminated, is a kind of quantitative form. Hence the infinite of quantity is the infinite of matter; such a kind of infinite cannot be attributed to God; as was said above, in this article.

3. The fact that the being of God is self-subsisting, not received in any other, and is thus called infinite, shows Him to be distinguished from all other beings, and all others to be apart from Him. Even so, were there such a thing as a self-subsisting whiteness, the very fact that it did not exist in anything else, would make it distinct from every other whiteness existing in a subject.

Whether anything but God can be essentially infinite?

Objection: 1. It seems that something else besides God can be essentially infinite. For the power of anything is proportioned to its essence. Now if the essence of God is infinite, His power must also be infinite. Therefore He can produce an infinite effect, since the extent of a power is known by its effect.

2. Further, whatever has infinite power, has an infinite essence. Now the created intellect has an infinite power; for it apprehends the universal, which can extend itself to an infinitude of singular things. Therefore every created intellectual substance is infinite.

3. Further, primary matter is something other than God, as was shown above (Question [3], Article [8]). But primary matter is infinite. Therefore something besides God can be infinite.

On the contrary The infinite cannot have a beginning, as said in Phys. iii. But everything outside God is from God as from its first principle. Therefore besides God nothing can be infinite.

I answer that Things other than God can be relatively infinite, but not absolutely infinite. For with regard to infinite as applied to matter, it is manifest that everything actually existing possesses a form; and thus its matter is determined by form. But because matter, considered as existing under some substantial form, remains in potentiality to many accidental forms, which is absolutely finite can be relatively infinite; as, for example, wood is finite according to its own form, but still it is relatively infinite, inasmuch as it is in potentiality to an infinite number of shapes. But if we speak of the infinite in reference to form, it is manifest that those things, the forms of which are in matter, are absolutely finite, and in no way infinite. If, however, any created forms are not received into matter, but are self-subsisting, as some think is the case with angels, these will be relatively infinite, inasmuch as such kinds of forms are not terminated, nor contracted by any matter. But because a created form thus subsisting has being, and yet is not its own being, it follows that its being is received and contracted to a determinate nature. Hence it cannot be absolutely infinite.

Reply to Objection: 1. It is against the nature of a made thing for its essence to be its existence; because subsisting being is not a created being; hence it is against the nature of a made thing to be absolutely infinite. Therefore, as God, although He has infinite power, cannot make a thing to be not made (for this would imply that two contradictories are true at the same time), so likewise He cannot make anything to be absolutely infinite.

2. The fact that the power of the intellect extends itself in a way to infinite things, is because the intellect is a form not in matter, but either wholly separated from matter, as is the angelic substance, or at least an intellectual power, which is not the act of any organ, in the intellectual soul joined to a body.

3.: Primary matter does not exist by itself in nature, since it is not actually being, but potentially only; hence it is something concreated rather than created. Nevertheless, primary matter even as a potentiality is not absolutely infinite, but relatively, because its potentiality extends only to natural forms.

Whether an actually infinite magnitude can exist?

Summa Th. I EN Qu.5 a.3