Cursus Philosophicus Thomisticus, Secunda Pars Philosophiae Naturalis

Generally speaking, every increase or decrease is called quantity, wherever it occurs, because what is most perceptible and evident to us in the increases of things is quantity. This account of quantity can be found in qualities or forms in three ways. First, by extension in a subject; this belongs only to qualities inhering in a subject that has quantitative parts, as when whiteness is diffused through a subject and grows in it because it is in more parts of that subject. In this way a quality is called great or quantitatively large per accidens, by the quantity of its subject. Second, quantity or magnitude is attributed to a quality on the side of the object about which it is concerned. This applies to habits of intellect or will, which concern certain objects and comprehend sometimes more and sometimes fewer of them; in this respect they are said to extend or increase in relation to their objects. This is called virtual extension, or quantity of power, because a power is called great in relation to the object, or the weight, it can bear. Third, a quality’s quantity or magnitude is said according to its participation in a greater perfection through more and less. This pertains to intensification and remission, on which see St. Thomas, De virtutibus, q. 1, a. 11, ad 10.¹

Concerning this intensification, then, we assume two things in the present article and discuss one of them, the more difficult one.

First, we assume that such an increase by intensification and a decrease by remission exist; this pertains to the question whether they exist. This is evident from experience itself. We see qualities increase or decrease in more and less, and this cannot be reduced to the other two extensions or magnitudes just described. For we see heat, whiteness, or light sometimes become more perfect and greater, not because it occupies more parts of the subject—it occupies the same parts—nor because the subject is denser or rarer. In the same air, for instance, sunlight is more perfect than moonlight, though the air has the same rarity. This increase therefore does not pertain to quantity by formal extension. Nor does it pertain to virtual extension, since light, heat, and similar qualities do not have different objects about which they are concerned, but rather subjects that they inform. It remains, then, that there is a quantity and increase by intensification according to more and less.

Second, we assume a definition of intensification; this pertains to the question what it is. Intensification may be defined as “motion from a less perfect being or state of the same quality to a more perfect one, while the same sensible subject remains”; remission, conversely, is “motion from a more perfect to a less perfect state.” So teaches Master Báñez² in q. 2, On Alteration. The phrase “from a less perfect being or state” is used so that the definition abstracts from every opinion about whether intensification occurs through different degrees, different modes, or different participations in being; we shall discuss these later. It is called “motion,” the genus of alteration and consequently of intensification. But since not every intensification occurs through alteration properly so called, as happens with spiritual qualities, we use the general term “motion.” This also excludes the acquisition of a new state in some quality or form, not through motion but through an elevation or a different mode of operation, as when charity in this life changes its state in heaven—not through greater intensification and motion, but through a new apprehension of an object clearly seen. Finally, the phrase “of the same quality to a more perfect state or being” signifies how intensification differs from simple alteration: simple alteration first and per se produces the quality itself, not merely a more perfect state or being of that quality.

We inquire, then, which forms are capable of this increase and magnitude according to more and less, namely, intensification and remission. This difficulty must be resolved through several conclusions.

I say, first: Substance is incapable of an increase by intensification, and so too are quantity and relation.

This is the Philosopher’s express teaching, and all his interpreters commonly follow it. In the chapter “On Substance,”³ one of its properties is said to be that it does not admit more and less. He teaches the same about quantity in the chapter “On Quantity,”⁴ and about relation as well,⁵ which admits more and less only by reason of its foundation. For example, similarity is more intense when the agreement of its extremes is greater, even if the forms themselves or the things are less intense in themselves. Thus the intensification of a relation follows the intensification of its proximate foundation, not its remote one.

The foundation of this conclusion can be taken generally: no motion is given primarily and per se in these three categories, strictly speaking—that is, motion according to a positive range—whereas intensification is a kind of motion. If some motion is given, it is according to extension, as in the increase of quantity. Substance, as is clear, comes to be through a change and not through motion, since it does not come to be from the same sensible subject but from prime matter. Likewise, when quantity is first produced, it follows generation itself without another motion. When it is later extended, it admits the motion of growth, but not alteration and intensification. Thus one part of quantity added to another does not make a more perfect degree, but an extension of a perfection of the same kind: it makes something greater, not better. This is especially clear because the species of quantity vary essentially according to different terminations, as is evident in numbers and figures, in a two-cubit and a three-cubit length, and so on. It belongs to their account to be indivisible or terminated; therefore they do not admit a range within the same species. Finally, there is no per se motion to relation, as is said in Physics V and as we proved there, q. 19,⁶ since relation merely results once its foundation is posited; no motion is directed to relation. Thus relation does not have intensification primarily and per se; if it has it at all, it follows from its foundation.

Second, the foundation is taken specifically from St. Thomas in Summa theologiae I–II, q. 52, a. 1: the form from which the species of the thing it actualizes is taken cannot fail to consist in something indivisible and consequently cannot admit more or less. For if what constitutes the species had a range, then either that whole range would be required to constitute the species, or the species could be constituted without the whole range, even if some part were lacking. In the first case, divisibility is not preserved in such a form, since the species is constituted not by its range as such, but by its totality and completion, which implies indivisibility; for what is ultimate is always indivisible. In the second case, the species is preserved without some part of that range, and what can be lacking without the species being lost does not belong to the constitution of the species or count as a quidditative predicate, since the quiddity is preserved without it.

From this it follows that a substantial form does not admit more and less, because it is intrinsically ordered per se to constituting the substantial species of the thing whose form it is. Although quality and other accidents also have their own species and essence, those forms are not ordered to constituting the species of their subject, which they inform; they presuppose that species as constituted and therefore do not first and per se constitute the species of what they inhere in. A substantial form, however, first and per se constitutes the species of what it is in; for this reason substantial form is incompatible with intensification, or the reception of more and less. An accidental form does not have this incompatibility on that account, although other conditions are required for intensification to belong to it in fact. For now it suffices that a substantial form gives the thing in which it is an essential and per se species, whereas an accidental form does not but presupposes the species as constituted. St. Thomas was therefore precise in the passage cited: he did not say that substantial form does not admit more and less simply because it has a species or gives it in some way, but because what participates in such a form has its species according to that form. We must therefore consider the function a form exercises in its participant or subject, in which it is received. If a subject is related to a form in such a way that through it the subject has its species and constitutive principle, that form does not admit more and less in that participant. As for other forms, which come to a subject without giving the participant its species, but rather come to something whose species is already constituted, there is no incompatibility on this account with their having some range in that subject. This is so even though they have a species of their own, provided that it does not constitute the subject in which they are participated; their participation in a subject can therefore admit a range of more and less.

But if you say: Every species consists in something indivisible, for species are like numbers, which change whenever anything is added or subtracted: We reply that it is one thing for a species, as regards its constitution, to consist in something indivisible, and another for the subject participating in such a form to be constituted by that very indivisibility, or for indivisibility itself to be a predicate among the constitutive principles of that species. This is not found in every species. Therefore not all species are incompatible with the divisibility and range they have in the subject’s participation, even though every species is said to consist in something indivisible on account of the integrity it requires of all essential predicates for its constitution. Not every species, however, excludes divisibility on the side of the subject’s participation, from which the range of intensification is taken, as we shall say shortly.

I say, second: Intensification is found only in quality, though not in every species of quality.

If we speak of physical intensification, which is a species of alteration, there is no doubt that just as alteration is found only in the category of quality, so too is intensification, its species. But lest someone say that intensification can be found in spiritual things and not only in alteration, the conclusion must also be proved more generally. First, there can be no doubt that intensification is found in this category, at least in some of its species, since this rests on manifest experience: we see heat sometimes intensified and sometimes diminished. The same holds for the other primary qualities and for intermediate qualities, such as color, rarity, density, and the like.

Considering the species of this category one by one, and asking which can undergo intensification not only in the altering sense (for this is reduced to the third species alone, just as alteration itself is), but also in the broader sense, we see first that habit and disposition can be intensified. Habits of the virtues are sometimes more vigorous and sometimes more remiss; likewise, knowledge is sometimes deeper and more effective, sometimes duller. This is not only a matter of extending to different conclusions: with respect to the same truth, there can be greater clarity and a deeper resolution to its principles, which pertains to greater intensification. Thus someone is called more knowledgeable or more virtuous. This also extends to supernatural habits, as is said of charity in Philippians 1:⁷ “I pray that your charity may abound more and more”; and in the last chapter of Revelation:⁸ “Let the one who is just be justified still.” Finally, the Council of Trent, Session 6, chapter 10, defines the increase in justice of those who have been sanctified.

As regards the second species, some think it does not admit more and less—for example, intellect, will, and the visual power—because these are proper attributes and follow immediately from the essence of a thing by emanation, not by motion, and they do not belong to a subject according to a range of contrariety. Master Báñez takes the opposite view in On Generation, Book I, chapter 4, q. 3, final conclusion; he gives the example of the visual power, which evidently admits more and less: sometimes sight is sharper, sometimes duller. An eagle certainly sees more intensely than a human being; among human beings, some see better and more keenly than others; and after the resurrection the eyes of the same human being will see incomparably more keenly than they do now. It is no objection that these are proper attributes of the soul, since heat and dryness and the other primary qualities are also properties of the elements and yet admit more and less. Cajetan takes a middle position at the end of Summa theologiae I–II, q. 52, a. 1,⁹ and says that natural powers which follow substances immutably are not intensified, just as substances themselves are not; those that do not follow immutably but depend on some alteration, such as hardness, softness, and similar qualities, can admit more and less. Since powers attached to bodily organs depend on the altering qualities that temper those organs, it seems that they can admit more and less: the visual power, for instance, can be sharper, as can hearing, and so on. This view seems quite reasonable. There is no reason why powers of this kind, which depend on primary qualities or alteration, should not admit more and less, especially since experience supports this: we perceive intensification and remission in them, as is evident in the visual power, in softness and hardness, and in other cases. Nor is it an objection that they come to be instantaneously, since some things that come to be instantaneously can also be intensified, such as light and spiritual acts of intellect and will. Some powers are not intensified, as Cajetan says,¹⁰ because they follow a nature immutably—that is, independently of altering qualities. In particular, powers belonging to something according to the ultimate constitutive degree of its nature, such as intellect and will according to the rational degree, do not admit more and less because that degree itself signifies a kind of ultimacy. Thus the rule is not whether a quality is a proper attribute, but whether something indivisible belongs to the account of a form, as we suggested above. Accordingly, some powers do not receive a range of more and less because they follow substance immediately and independently of alteration; other powers, which do not follow it so immediately and are not independent of alteration and primary qualities, admit more and less by reason of those qualities.

As regards the third species of quality, there is no doubt that intensification can be found in it, and that it can be physically altering, since, as we proved in the preceding question, physical alteration properly occurs in the third species of quality; consequently intensification, which is its species, can occur there as well. This is also evident to the senses from heat, cold, and the other sensible qualities belonging to this species.

Finally, in the fourth species of quality there is no motion of intensification, because the account of figure, which belongs to that species, includes the termination of quantity from which figure results; any variation in termination changes the species. Termination occurs according to something indivisible and therefore is incompatible with a range of intensification.

I say, finally: Besides intensification, which is motion according to more and less, and besides extension through the quantitative parts of a body, there is also, in some qualities, an increase by extension—not according to the parts of the subject in which the quality inheres, but according to the objects it reaches, since those objects are inadequate. A habit is said to increase more extensively insofar as it reaches different objects.

This is taken from St. Thomas, Summa theologiae I–II, q. 52, a. 1, ad 2, and II–II, q. 24, a. 5, where he teaches that some habits increase by addition with respect to their objects. For example, knowledge, which is learned gradually, newly increases with respect to different conclusions it did not previously reach. This increase is not intensification, since it does not concern the same truth but different ones. Knowledge is intensified when it comprehends the same truth more clearly and deeply.

Concerning this extensive increase, note three propositions of St. Thomas. The first is that such an increase does not occur in every form or quality, but in those specified by something extrinsic or expressing an order to another. So he teaches in Summa theologiae I–II, q. 52, a. 1, at the end of the body of the article.

The second is that this increase is not found in every habit expressing an order to a specifying object. Charity, for example, expresses an order to an object, yet it does not admit addition by extensive increase, as St. Thomas teaches in the cited Summa theologiae II–II, q. 24, since the least charity fulfills the whole law and resists every temptation; every degree of charity therefore reaches all its objects, namely God and neighbor. It does not become greater by extending to objects. Knowledge, however, needs this extension because it proceeds through distinct means to prove distinct conclusions. Although all those means are coordinated with one another and belong to the same habit under the same light, they require different explanations of the object, distinct species or their arrangement, and distinct means of proof. We discussed this more fully in Logic q. 27, a. 2.¹¹

But if you say: Moral virtues, even when infused, can also face a new difficulty concerning different partial objects, as we said in the cited passage of Logic;¹² indeed, we drew from this an argument to prove that knowledge is a simple habit, although it overcomes distinct inadequate difficulties. Therefore it is false and inconsistent to say here that moral virtues do not admit addition, but knowledge alone does.

We reply that, as we said in the cited passage of Logic, in the answer to the confirmation of the first argument,¹³ infused virtues such as charity and faith can face different difficulties concerning different matters, not on the side of the virtue itself but on the side of the agent; this is an accidental difficulty, and yet a single simple quality suffices to overcome them. So too one quality will suffice in the sciences to overcome distinct difficulties concerning distinct conclusions, although it requires different inadequate motives for them, since those motives are united under the same formal account and light. The motives are coordinated with one another, since one is derived from another. Thus a strong argument from similarity proves that one quality suffices to reach different conclusions, even though each has its own proof and distinct motive, and a distinct difficulty on the side of the means themselves, not only on the side of the agent. There is still room for unity of habit, because its principal account, from which its unity is taken, is preserved—namely, the same formal scientific account under which all those motives and proofs are coordinated and contained. Therefore, if one quality can reach distinct matters and overcome distinct difficulties on the side of the agent, provided that the same formal account is preserved, as is evident in the virtues, then with the unity of the formal account preserved, it is likewise possible for the same quality to reach different conclusions and overcome distinct difficulties that require distinct means, all ordered under the same single formal account and light.

The third proposition is that St. Thomas says this extensive increase occurs by addition, by which a habit is increased in itself, whereas intensification occurs through rooting in the subject and not by addition. This is not because a new quality is added in extensive increase (St. Thomas denies this in Summa theologiae I–II, q. 54, a. 4), but because a new objective increase is added, and because an order to an object is said to belong to a habit in itself, whereas participation and the rooting of intensification occur through an order to the subject, according to St. Thomas’s view. Thus, to distinguish one increase from the other, the former is said to occur by addition, while the latter is not: in the former a new object and a new expression of the habit in relation to it are added; in the latter no new subject is added, but intensification takes place in the same subject. Nor is a new entity of quality added, so there is addition in no respect.

The arguments are answered.

First it is argued: Intensification cannot increase a quality according to more and less unless the species and essence of the quality itself vary. Therefore the account given of intensification is null. The antecedent is proved as follows: that according to which a quality becomes more or less is the proper account and species of the quality itself; but species are like numbers, changing whenever anything is added or subtracted.

If one says that intensification occurs according to more and less not in the essential and specific account itself, which consists in something indivisible, but in something extrinsic—for example, through the addition of a degree or new entity, or through greater participation or rooting in the subject—there is an objection. First, intensification cannot occur by adding a new quality of the same species, as we shall say in the next article. Nor can different participation and rooting in the subject occur according to something accidental, but only according to the very essence of the quality. St. Thomas says that the opposite view is ignorance of the proper meaning of the words, in Summa theologiae II–II, q. 24, a. 4, ad 3, and De virtutibus, q. 1, a. 11.¹⁴ Therefore variation through intensification occurs in the very essence. Further, if intensification does not occur through a variation in the essential account, or species, of the quality itself, but in something extrinsic or pertaining to individuation, it follows that substantial forms could be intensified, since their indivisible species could be preserved while they increased according to more and less in something extrinsic and individual—for example, by being united to a subject in a more perfect way or by being the root of a more perfect mode of operation. Why, then, would there not be an increase by intensification in substantial forms?

The same argument can be made about quantity. Through different modes of terminating a subject, it can be participated in that subject more or less perfectly in an extrinsic way that does not pertain to its intrinsic species. Why, then, would quantity not admit more and less?

We reply by denying the antecedent. To the proof we say that intensification does not vary the species, but the mode in which the species actualizes the subject and reduces it more perfectly from potency to act, as will be said in the next article. For an addition or subtraction to vary the species of a form, it must add or subtract a quidditative predicate, or an intrinsic mode of such predicates essentially required. It is not enough to add or remove merely some mode of different participation in the subject or the addition of a new quasi-integral entity, as we see that more or fewer integral parts can be added to or subtracted from a material substance without varying its species.

To the first rejoinder we say that intensification does not occur through the addition of a new entity, but through greater rooting in the subject, as we shall say in the next article. St. Thomas says that those who claim a form is increased by rooting in the subject and not according to its essence are ignorant of the proper meaning of the words because they understood rooting not to pertain to the entity of the accident, whereas the entity of an accident itself demands inherence and participation in a subject; thus greater rooting undoubtedly involves the entity itself. St. Thomas therefore says in the cited place in Summa theologiae II–II that increasing something according to its essence is nothing other than its being more in the subject, which is its being more deeply rooted. We shall discuss this further in article 3.

To the second rejoinder we say that a substantial form is prevented from being intensified because it has no range or contrariety by which it could be capable of motion and consequently intensification, as was said above.¹⁵ Although an indivisible species of form could remain while a divisible increase according to more and less took place, this does not occur in a substantial form, because it not only has a species in itself, but constitutes in its species the composite it informs. Thus it establishes no range either on the side of its species or on the side of its participation and the participating subject. If it is varied in any way, its whole species is varied, both in itself and in the subject’s participation. The case is different with an accident: through its participation the subject itself is not constituted in its essential species but is presupposed as already constituted. On this account, an accidental form is not prevented from being intensified or remitted. It does not follow, however, that all accidental forms can be intensified or remitted if they lack other conditions, such as contrariety or a range, so that their indivisibility in constitution is not intrinsic and does not belong to their account. We noted this above concerning the constitution of species of quantity,¹⁶ and concerning other species of quality that lack a range and include indivisibility.¹⁷

But if you say: Aristotle in Metaphysics VIII, text 10,¹⁸ and St. Thomas there, lecture 3,¹⁹ say that matter perhaps admits more and less. St. Thomas replies in Summa theologiae I–II, q. 52, a. 1, that this is understood of matter according to its material dispositions, not according to its substance, according to which it composes with form an indivisible species of nature.

Second, you will object: A quality has contrariety in itself, prior to its relation to a subject—for example, it is contrary to cold. It does not derive its contrariety from its subject. But where there is contrariety, there is the greatest distance; therefore there is also a range according to more and less, and consequently intensification and remission. Indeed, contrariety between forms exists only according to degrees, for qualities are not contrary at remiss degrees but at intense ones, where alone they are incompatible. Therefore they are said to have more and less not in relation to a subject, but in themselves.

Again, if God were to separate the whiteness of snow and the whiteness of a human being, the former would be more perfect than the latter, not through rooting in a subject, since they would be outside a subject; therefore, this would be according to themselves, and so it would not be incompatible with substance to have intensification.

Finally, the whiteness in the concrete and the whiteness in the abstract are the same. Therefore, if whiteness in the abstract is not intensified, neither is it in the concrete; or conversely, if it is intensified in the concrete, it is also intensified in the abstract. If an accident in the concrete, such as “white,” is taken not for the form existing in a subject but for the composite of body and whiteness, then it is not intensified, because one of its constituents, the body, is not intensified.

We reply that although some qualities ground contrariety in themselves, as between form and form, and not only according to a subject’s participation (although contrariety cannot be exercised except in a subject, since contraries drive one another out of the same subject), the range and distance according to more and less in the intensification of forms is not taken from some contrariety between form and form, but from the range of the form’s participation and rooting in the same subject. When it is said that where there is the greatest distance there is also a range of more and less, we reply that this is more and less among different forms that are not the extremes but intermediates between contrary extremes. More and less in the same form, however, do not ground contrariety and distance except with respect to the subject in which the form is rooted and participated. Thus contrariety between form and form, whether according to the greatest distance or according to intermediate forms, belongs to forms in themselves; distance according to more and less in the same form belongs to it only according to its different participation in a subject. Contrariety between form and form therefore comes from the very nature of such forms, although a perfect state is required for contrariety to be exercised, and this occurs only in perfect degrees, since imperfect degrees are reckoned within the same subject, as we shall discuss below, q. 10.²⁰

As for the whiteness of a human being and of snow when separated, we reply that one will be more intense than the other, not because it is actually more deeply rooted in a subject, since they lack one, but because of the aptitudinal rooting they retain and the order they express toward a subject. When St. Thomas says that separated whiteness has every perfection possible and cannot be intensified, he is speaking of whiteness if it were subsistent and referred to a subject neither actually nor aptitudinally.

Finally, concerning what is said about whiteness in the abstract and in the concrete, we say that it is the same form, but not in the same state or with the same relation: in the concrete it regards a subject, whereas in the abstract it leaves the subject aside. Hence St. Thomas says in Summa theologiae I–II, q. 53, a. 2, ad 3, that intensification and remission are attributed to accidents in the concrete; thus we do not say “more whiteness,” but “whiter.” “White,” taken for the composite, is not intensified by reason of the whole, but by reason of a part—namely, by reason of the form insofar as it can be communicated to a subject.