Cursus Theologicus, Tomus I: In Primam Partem

1 For an understanding of the title, it must be noted, with Nazarius, 1 parte, quaest. 3, art. 2, controvers. unica; Gonzalez, quaest. 11, disp. 23, num. 12, and with the common school of the Thomists, that we can speak twofold concerning the principle of individuation of material substance: first, of the total and adequate first principle, namely of everything that concurs essentially and directly to constitute the material individual as such, namely this form, this union, and likewise this matter and its union with this form; and accordingly, in the opinion of St. Thomas, concerning matter in some way determined by a quantity, through which matter itself becomes this, as will be seen below. Secondly, concerning the radical principle, which is the first root to which all individuation is ultimately reduced.

The title of this question, and also of the entire disputation, is therefore understood not as concerning the former principle, but as concerning this latter principle of individuation and of purely individual distinction, by which one composite is distinguished from another; because this principle, when compared with all the others, has the stronger claim to be the first and radical principle, as is evident from the terms themselves and will appear more fully below. We have said: of purely individual distinction; because here we are not speaking of individual distinction mixed with specific distinction and arising in some way from it—as, for example, this man and this horse are distinguished—nor of individual distinction that does not contain specific distinction mixed with it, and therefore rests purely within the range of individual distinction.

Accordingly, we are not speaking of the principle of individuation taken metaphysically. First, because it is certain that every material individual is individuated metaphysically by its individual difference, which constitutes it under a species and distinguishes it from every other thing that partakes of that species atomically. Secondly, because it is sufficiently established that the difference, or the individual principle understood in this way, must be derived from some physical principle that is the first origin and first root of the metaphysical reason of individuality, so that the aforesaid individuation is ultimately reduced to it. Thus, to investigate the first principle absolutely so understood is the same as to investigate the principle of the individuation of matter considered in the physical order.

2 Accordingly, neither Scotus, 2 Sententiarum, dist. 3, quaest. 3, nor Fonseca, 5 Metaphysic. cap. 6, quaest. 5, sect. 1, touched on the point of difficulty debated throughout this entire disputation by the Doctors while settling it; they merely say that haecceity, or the metaphysical individual difference, is the principle of individuation. For, as we said a moment ago, the controversy and the point of difficulty concern only the first and fountainhead principle of individuation, into which individuation itself is entirely resolved; and accordingly they concern the first principle and physical root, as we recently said.

We have nevertheless added to the title that qualifying term, intrinsic, so as to indicate that the present discussion is not about the first extrinsic principle, such that an efficient cause, and particularly God, is the first principle of the individuation of any creature, but about the first intrinsic principle of the individuation of the entire substantial composite.

§ I. The first opinion is proposed.

3 The first opinion asserts that substantial form is itself the individual and the first, or principal, radical principle of individuation. Thus Nimphus, 5 Metaphys., disput. 5; Sebastian. Perez, Episcopus Oxomens., 3 de anima, conclusione 1; Zimara, theoremate 97; Suarez, disput. 5 Metaphysic., sect. 4. In support of it are also cited: Averroës, 1 de anima, cap. 7 and 3, Physicor. comment. 60, and lib. 4, comm. 38; Avicena, 6 naturalium. parte 1.

It is proved first. For the first and radical principle (of which we are speaking) of the individuation and purely individual distinction of a substantial composite must have two properties: first, that it be intrinsic to the composite itself; secondly, that it be most proper to it as this, individual being; therefore this principle will be substantial form and not something else. The antecedent is evident. For just as the first principle of the specification of the same composite cannot fail to be intrinsic and most proper to it as constituted in its species, so the first principle of the individuation of the aforesaid composite must intrinsically constitute it in the being of an individual and must be very proper to it as considered in the being of such. The consequence, however, is proved and explained as follows. Form, as will be evident to the observer, has these two properties, and nothing except form possesses them, because neither accidents can be intrinsic to the aforesaid composite as this, individual being; otherwise it would not be one per se in the being of such, as is clearer from itself and from what will be said below. Nor can matter, although intrinsic to the composite, be most proper to it; for the very matter that now constitutes one substantial individual can immediately constitute another.

4 It is confirmed first. For that is the first and radical principle of the individuation of a substantial composite which is the first principle with respect to its being; accordingly D. Thom., quaestione unica de anima, artic. 1 ad secundum, said: each thing has the same being and individuation; therefore form will have the character of the aforesaid principle. The consequence is evident, because form alone is the first and radical principle of existing; hence matter does not have its own existence from itself, but only by reason of form, as our Complutensians teach in libro Physicor., disp. 3, num. 70.

It is also confirmed and explained secondly. For something to be the principle of individuation, and therefore of individual distinction, actually first, presupposes that it be a being first in actuality; therefore the character of such a principle will belong to substantial form alone. The antecedent is evident. For just as being the principle of anything whatsoever presupposes an entity of the principle, so being the principle first in actuality presupposes that it be a being first in actuality. The consequence, however, is proved because, insofar as matter is from itself, it is only a being in potency, since it has only pure potency as its being; form alone, on the contrary, is a being first in actuality, since form alone is in itself and essentially an act, just as matter alone is essentially pure potency.

5 Secondly, and principally. For the first and radical principle of specific unity is form alone; therefore form is likewise the principle of individuation. The antecedent is commonly accepted by philosophers and dialecticians and follows from what our Complutensians assert in Logica, disput. 5, num. 75. The consequence, however, is proved as follows. Specific unity in a substantial composite is taken from form as from the first and radical principle because, although it cannot exist without matter, it nevertheless presupposes matter as something potential and indifferent; form, however, removes this indifference and gives the ultimate essential and specific complement. Therefore, since the same form gives the ultimate substantial complement to the substantial composite as this, individual being—and hence Aristotle, 1 de anima, capite 1, said that form is what constitutes this something—and presupposes matter as something potential and indifferent, the conclusion follows that it is likewise the first and radical principle of individuation. Otherwise, under the specific concept an objective substantial concept common to many individuals of that species and to no others could be given, which appears absurd.

6 Thirdly. For this determinate form does not regard this determinate matter in such a way that, insofar as its own power is concerned, it could be naturally received in it alone; therefore it is not this and individual by reason of that matter, but by reason of itself; therefore it will itself be the first and radical principle of the individuation of the entire composite. This final consequence is evident from the previous one. For otherwise form might be denied the character of the aforesaid first and radical principle, because it would not be individual by reason of itself but by reason of matter; accordingly matter would have to be the first root of individuation. The first consequence, however, follows from the antecedent. For if form were individual by reason of matter and not by reason of itself, form would for that reason be this, because it seeks to be received in this determinate matter and not in another; accordingly, if the very same form can naturally be received in another matter, this is a sign that it is not this and individual by reason of matter, but by reason of itself.

The antecedent, however, is proved as follows. First, because the very same determinate matter which is under the form of an embryo is afterward under an animal form, for example, that of a horse; accordingly, the very same form that is now in this matter could, insofar as the form’s power is concerned, be in other matter; for act and potency, insofar as they are from themselves, must correspond to one another. Secondly, because if this soul—for example, a horse’s soul—were fit by itself to inform only this numerically individuated matter, then all horse souls that could inform that numerically individuated matter at different times would have among themselves some real correspondence that they would not have with horse souls informing other matters; for all of them would have the aptitude to inform this numerically individuated matter, which other horse souls cannot inform; and—

7 It is confirmed. For if the same numerically identical substantial form informs different matter at different times, the composite resulting from it would be numerically identical with that which previously consisted of other matter and the same form; therefore this is a sign that form is the first and most powerful principle of the individuation of the entire composite, according to whose change or invariance the individuation of the aforesaid composite changes or remains the same. The consequence requires no proof. The antecedent, however, is proved. For in the general resurrection individual men rise again with their numerical unity, because although by chance two may have had the same matter, and that matter is bestowed on only one of them, as occurs among those who feed on human flesh, nevertheless each receives his own rational soul, and this soul will draw whatever matter to its own proper unity.

8 Fourthly. For if for some reason form were not the first principle of the individuation and purely individual distinction of the entire composite, especially because form itself is limited by matter, this reason would be null; therefore, and so forth. The major appears manifest. For since the individual difference is intrinsically limiting and determinative of the specific reason arising from form itself, it will be inferred most fittingly that the aforesaid form is not the first principle of that difference if it is not intrinsically limited, but must be limited by matter as by the first principle. The minor, however, is proved. For otherwise neither matter, and consequently nothing else, could be the first principle of the aforesaid individuation. For just as matter limits form, so form limits matter, and so with regard to the other things concurrent in individuation, as is sufficiently clear from themselves and from what St. Thomas teaches, 1 p. part., quaest. 7. Lastly, because at least the intellectual soul is individuated from itself and is the first principle of individuation; accordingly D. Thom., 2 contra gentes, c. 75, in the solution to the first reason, and c. 81, says that just as the being of the intellectual soul is not caused by matter itself, so neither is its unity or individuation.

§ II. The opinion of Aristotle and St. Thomas is more acceptable.

9 Nevertheless, it must be said that substantial form is not itself individuated in such a way as to be the first and radical principle of the individuation and purely individual distinction, whether with respect to itself or to the entire composite; and accordingly, it is not such that the entire aforesaid individuation and distinction is ultimately reduced to it. Thus Aristotle, 5 Metaphysic., cap. 6, in fine, where he says that the distinction of individuals within the same species proceeds from the divisibility of matter. In lib. 12, cap. 8, he asserts that things which are many in number have matter; and from this he concludes that the first mover is one not only in reason but also in number, because, being an act, it has no matter. If, on the contrary, substantial form were individuated in itself, such that it had the character of the first and fountainhead principle of individuation and individual distinction, whether with respect to itself or to the entire composite, then numerical distinction would proceed from form itself rather than from matter and its divisibility. Likewise, when Aristotle speaks in the same way of physical matter, as is clear from the context and as Nazarius has shown well, 1 part., quaest. 50, art. 4, controversia 1; Ferrara, 2 contra gentes, cap. 93, ratione secunda, [he] would not correctly infer that the first mover cannot be multiplied numerically from the fact that it has no physical matter, namely first matter, as is clear from the context. For if substantial form is once numerically one in itself, so that it is for itself as well as for the composite the first reason of unity and purely numerical distinction, then with stronger reason a complete form subsisting per se, such as the first mover, would have this property with respect to itself. The Philosopher asserts the same, 10 Metaphysic., text. 25, where, assigning the first and fountainhead principle of unity and of specific and individual distinction, he says that form is the first principle of unity and specific distinction, but matter is the principle of individual distinction; and thus he says: For this is the reason and this is the matter: whatever oppositions are in the reason make a difference of species; but those which are in the concept together with matter do not. St. Thomas explains these words in the same place, lect. 11: For in the composite there are matter and form; the former is the reason, that is, form, which constitutes the species; the latter is matter, which is the principle of individuation. Whatever oppositions are in the reason, that is, on the part of form, make a difference of species. But those on the part of matter, which are proper to the individual that is assumed together with matter, do not make a difference of species.

10 The holy Doctor taught this very point also in secundo contra gentes, capite 93, ratione secunda, in these words: Whatever things are the same in species but differ in number have matter; difference, however, which proceeds from form produces diversity of species; but that which is from matter produces diversity according to number. The same Doctor teaches this also in prima parte, quaest. 50, artic. 4, de ente, et essentia, capit. 6, and in 2 distinct. 3, quaest. 1, artic. 4, where, to give the reason why Angels cannot be distinguished by number alone on account of their being immaterial, he says: For if they are supposed to be immaterial, since neither form nor nature can multiply number except through diversity of matter, it follows that a simple, immaterial form not received in any matter can be only one. Therefore, whatever is apart from it is of another nature, because it differs from it according to form, not according to a material principle, which is absent there. Finally, D. Thom. very often repeats this same doctrine, as will be clear from the places cited at num. 43. Accordingly, both Aristotle’s disciples and the Angelic Doctor’s, together with many others whom we shall mention at num. 44, commonly follow him.

§ III. The opinion of Aristotle and St. Thomas is explained, and the first reason in support of it is discussed.

11 But because this assertion requires some explanation, it must be explained briefly before it is proved. The qualifying clause was deliberately added to it, namely: such that it be the first and radical principle of purely individual distinction, whether with respect to itself, etc. By this it was to be indicated that the assertion does not deny that form is individuated in itself and through its intrinsic entity; for in itself and through its intrinsic entity, form regards this matter immediately and not that other matter, and by reason of this relation it is immediately and proximately singular. What we deny, however, is that the aforesaid form is individuated from itself as from the first and radical principle, or that it individuates the composite; and accordingly, that this whole thing derives its origin elsewhere, as from a first source and root.

Although this assertion, thus explained, can be proved sufficiently effectively from that second reason of St. Thomas which we shall present in the following question, no. 52, to prove that matter determined by quantity is the first root of the individuation already mentioned, nevertheless in this and the following section we shall demonstrate it by another twofold reason.

12 The prior and fundamental reason was given by the Philosopher and the Angelic Doctor in the places cited, and can be proposed in the following form. Since unity and distinction proceeding from form, as from the first and radical principle, are specific unity and distinction; therefore they are not the purely individual unity and distinction of which alone we are speaking; and accordingly, form will not be the first and fountainhead principle of precisely individual unity and distinction. This second consequence clearly follows from the first. The first, however, follows from the antecedent. The antecedent, besides being expressed by St. Thomas in the places cited, can be proved from the fact that specific unity and distinction is formal unity and distinction, because it is distinction according to essence, which is the formal something in each thing; numerical unity and distinction, however, is material unity and distinction. Therefore, since the distinction proceeding from form as first principle is formal rather than material—especially since numerical distinction arises from matter as from its first root—it follows that the unity and distinction proceeding from form as from the first root are specific unity and distinction.

13 This reason is so efficacious that, rightly developed, it easily overturns all the evasions by which our opponents meet it. For in the first place, some answer that not every unity and distinction proceeding from form is formal. For just as two acts and forms, or two rational souls, can be distinguished as acts and forms, and yet that distinction is not formal but material; likewise, two Angels, who are separate forms having nothing of matter, are individually distinguished. Thus some things can be distinguished on account of form, and by reason of it, and yet are not formally but materially distinguished.

This answer, therefore, easily collapses if the argument is rightly developed. For, on close inspection, it is repugnant that unity and distinction proceeding from form should not be formal, and accordingly specific. This can indeed be declared and explained as follows. Since distinction proceeding from matter, insofar as it is matter and is taken as the first and radical principle, cannot, insofar as it proceeds from matter, be formal or specific; therefore distinction proceeding from form, insofar as it is form and is taken as the first root, cannot be material either; but it must necessarily be formal, and consequently specific.

14 The consequence appears to follow from an equality of reason, and likewise from the example of a distinction proceeding from whiteness or heat. Since it proceeds from them as such, it cannot fail to be in the notion of whiteness or heat, because these effects are the proper formal effects of whiteness or heat; just as the proper formal effect of substantial form is to give substantial formal being. The antecedent is found in St. Thomas in the place cited from 10 Metaphysic., lect. 11, where he says: Therefore, if it is asked whether matter in any way makes things diverse in species, it seems that it does, because this horse is diverse in species from this man; yet it is manifest that the reason of each is together with individual matter, and thus it seems that matter somehow makes them differ in species. Nevertheless, it is manifest that this does not occur on account of the diversity of matter, but because the opposition is on the part of form. Thus it appears that the opposition on the part of form itself makes them differ in species, but not that which is on the part of matter. Thereafter the same antecedent can be urged as follows. First, because an effect cannot exceed its cause; and therefore formal unity and distinction cannot proceed as from a first root except from form. Secondly, because in material substances, although the generic reason can proceed from matter insofar as the aforesaid reason has potentiality and materiality, it cannot proceed from matter insofar as it retains actuality and formality; since according to this latter reason it proceeds from substantial form as such. Therefore this is a sign that being, or formal distinction, cannot proceed from matter as such.

15 It is confirmed and explained as follows. It is one thing for distinction to be exercised in forms, and another for it to proceed from those forms as such. Just as it is one thing for the possession of entitative parts to be exercised and found in material substance, and another for that possession to proceed from the same substance as such. Accordingly, it is not repugnant that the aforesaid parts be found, exercised, and communicated to substance by another thing as from a first root, namely quantity; and that nevertheless they be not formally but quantitatively substantial, as our Complutensians teach at length and learnedly in libro de Generatione, disput. 5, num. 58 and afterward. It is otherwise, however, if the aforesaid parts are exercised in substance and proceed from the substance as from a formal cause, for then they cannot fail to be formally substantial. The due proportion, however, being preserved, although it is not repugnant that a distinction exercised in substantial forms, proceeding elsewhere, namely from matter, should not be formal but material, it is otherwise if it is exercised in the aforesaid forms and proceeds from them; for then such distinction must be similar to its cause, and accordingly must be formal.

16 We have said: the due proportion, however, being preserved, so that a certain objection drawn from the example offered, which might have arisen here, remains answered. For we now compare only the matter at hand with the aforesaid example in this respect: just as the entitative parts of substance would have to be formally substantial if they proceeded from substance, and did not merely exist in it; but otherwise if they existed only in it, so distinction proceeding from form cannot fail to be formal, although a distinction exercised in it and proceeding from elsewhere, namely from matter, can fail to be formal and be material.

Nevertheless, it remains true that there is a disparity between the example and the matter under discussion, arising from the fact that the aforesaid distinction exercised in forms proceeds from matter as from a term that is in some way extrinsic, namely one that does not essentially constitute form; and therefore form is individuated and is proximately distinguished from another form by itself, that is, by the relation it has to matter. The entitative parts of substance, however, proceed from quantity as from an intrinsic formal cause, in the same way that being white proceeds from whiteness. Thus substance does not have parts, nor a distinction of its parts, by itself, that is, through the mere relation to quantity as to an extrinsic formal cause, but precisely insofar as it is subject to quantity and is informed by it.

Nor does the first example, which will be offered in this answer concerning two rational souls, establish anything. For two rational souls can differ materially even though they are acts and forms, because they are individuated through matter as through the first and radical principle of their individuation. Accordingly, although that distinction is exercised in substantial forms, it does not proceed from them; and thus it can fail to be formal and specific and instead be material and purely individual.

17 Nor does the second example concerning two Angels numerically distinguished on account of their individual differences prove anything. First, because, as we shall say below, the distinction between two Angels on account of their individual differences is not a purely individual distinction arising from purely individual differences; for in them specific and individual unity and distinction are not distinguished virtually, or on the basis of something in reality, but only on the part of our mode of conception, as we shall say in the treatise on Angels created by God. Thus that very individual distinction, so to speak, is specific distinction, and accordingly can and must arise from form insofar as form is form. Here, however, as we have already noted, we are speaking only of purely individual unity and distinction, which precisely because it is such must be material and proceed from matter. Secondly, because even if it is granted without qualification that in Angels the individual difference is virtually distinguished from the specific difference, this nevertheless does not weaken the force of our reason, as will appear more fully from what we shall say below at nn. 56 and 57, where we shall clarify this matter with the testimony of St. Thomas.

From what has been said, another solution employed by the opponents also collapses, namely that the distinction proceeding from form is formal and specific when it arises from form according to what is formal in form, but not when it proceeds from it according to what is material in it, although both are proper to such form and accord with it insofar as it is such. Nevertheless, because the individuation of the entire composite must proceed from substantial form according to what is material in it, not according to what is formal in it, distinction proceeding from form in this respect, namely according to the individual difference, or haecceity of form, can be material and numerical, but not formal and specific.

Thus, from what has been said, this evasion collapses no less than the preceding one. ¹ To understand this more clearly, it should be recalled what we said at no. 1, namely that we are not speaking of the individual difference, or of the material reason or principle of individuation, taken metaphysically, but of individuation, or the material reason and principle of individuation, taken physically; because every metaphysical reason must be founded in a physical entity, accepted as physical, and derived from it as from its first root.

18 Hence a fuller development of St. Thomas’s reason is drawn from this source, by which the aforesaid evasion vanishes. For either substantial form, accepted physically and according to what it is physically individual and the principle of individuation, says something material physically beyond itself, as it is the first principle of specification and specific distinction, or it adds nothing real, physically material beyond itself as it is physically form, and says only that it is physically formal being, as quod? If the latter is said, then form, according to what pertains to the physical order and has the character of a physical principle with respect to the composite, will be only the root of formal specific distinction; for in this order it adds nothing beyond itself that is physically material, but whatever is found in it is physically something formal, namely quod. If, however, the former is asserted, then that which is materially such must arise as from the first root, from matter; and accordingly, although it may be exercised and found in the substantial form itself (the only form of which we speak in this question), it must not proceed from it, but from matter; for just as formally being, and physically such, cannot proceed from anywhere except form, so material being, which has the character of such physically, cannot derive its order from anything as first principle except matter.

19 This is confirmed and explained from what we recently said, considered now in this form. Since something material and metaphysical with respect to metaphysical composition—that is, genus—is found in material substances, then, insofar as it is something material, it must arise as from the first root from matter itself and not from form, as Aristotle and St. Thomas, by an efficacious reason in Logica, disp. 5, num. 75 and afterward, show, as do our Complutensians. Therefore, since some other material reason is found in substantial form, and likewise in the composite arising from it, in the metaphysical order—that is, the purely individual difference of such form and composite from another of the same species—the aforesaid difference cannot fail to arise as from the first principle from matter and not from form itself. Thus every difference arising from form insofar as form is such, and thus as from the first physical principle to which such an effect is ultimately reduced, must arise from the same form according to what physically says being formally, namely quo; and consequently such a difference cannot fail to be at once formal and specific.

Finally, it is confirmed. For although a material form has material being in itself, as our Complutens. hold in 1 and 2 Physic., and likewise matter; nevertheless, when the two are compared, the first source, so to speak, of the materiality of the aforesaid form is matter itself, and not conversely. Therefore this is a sign that the entire material being of the substantial form and of the composite, and accordingly the individual difference of each, must arise from matter as from the first root. The consequence seems legitimate. The antecedent, however, is proved. For this causal statement is true: Because form is produced by matter, or because according to its being it depends on matter, the aforesaid form is material; but not conversely. Because material being is being potential, insofar as it is opposed to actuality and formality, it must proceed as from a first root, from the first in this genus, namely from first and pure potency, that is, from matter, according to that Aristotelian axiom: the first in each genus is the cause of those which are after it in that genus.

§ IV. A second reason is proposed for the Aristotelian and Thomistic doctrine,

20 The second and principal reason supporting the assertion, by which the solutions previously employed are more thoroughly refuted in answer to the preceding reason, can be reduced to this form. Since a form subsisting by its very nature, entirely separated from matter as from a receptacle, cannot be otherwise than one numerically—or cannot fail to possess the whole species fully—and therefore one cannot assign to it anything metaphysically or physically material on account of which it might be the root of its purely individual distinction from any other; therefore, precisely because a form is of such a condition that it can be multiplied numerically and can be in some way the principle of the individuation and multiplication of the composite, and therefore there is in it something material physically or metaphysically on account of which it can in either order be in some way the principle of purely numerical and individual distinction, this must arise as from the first principle, namely from the fact that that form is not entirely separated from matter as from a receptacle, but is ordered to it as to a receptacle and the first reason and root of such multiplication and purely individual distinction. Accordingly, the aforesaid receptacle will be the first reason for such multiplication. Just as, because sight is such insofar as it regards the visible, the visible is the first root and origin of all other things belonging to the visible order; and hence this causal statement is true and a priori: Because the visible is given, sight and vision are given. The antecedent is evident in Angels, who, because they are forms subsisting from themselves and entirely separated from matter as from a receptacle, possess everything mentioned in the same antecedent. This itself can be explained by the example of whiteness given by St. Thomas, 1 part., quaest. 50, artic. 4. Whiteness could not be otherwise than one numerically if it were separated from its subject both in actuality and in aptitude, such as in no way to bear a relation to it; for then it would have nothing from which it could be multiplied numerically.

The first consequence, however, clearly follows from the antecedent. For whenever the negation is the adequate cause of a negation, the affirmation is likewise the adequate cause of an affirmation. Thus, if the negation of purely individual multiplication in some form—and therefore that it can be only one numerically—is adequately inferred from its lack of matter and receptacle, there is no reason why its purely individual multiplication should be inferred as from the first root from the presence of matter and a receptacle in such form, or from the fact that form has matter and a receptacle in which it is received.

21 This reason is taken from St. Thomas in the place cited and in 1 part., quaest. 41, art. 6; e quaest. 44, art. 1; and quaest. 75, art. 3 de anima, lect. 8, which he himself derives from Aristotle in the same place, text. 8, in these words: The nature of a species is individuated through matter; hence individuating principles and individual accidents are beyond the essence of the species. Thus it happens that several individuals are found under one species which, although they do not differ in the nature of the species, nevertheless differ according to individuating principles. For this reason, in all things having form in matter, the thing itself and its quiddity are not altogether the same; Socrates, for example, is not his humanity. But in things which do not have form in matter, such as simple forms, nothing can exist beyond the essence of the species, because the form itself is the whole essence; and therefore several individuals of one species cannot exist in such things, nor can the thing and its quiddity differ in them.

This whole argument can be clarified further from the same holy Doctor. Individuals of the same species agree in a perfection intrinsically considered with respect to specific essence, such that the whole of that perfection is found in each of them, and they differ only with respect to diverse substantial modes of having it. But where the specific nature subsists by its very nature and is entirely—or both in actuality and in aptitude—separated from matter and a receptacle, no plurality or diversity of modes of having it can exist; therefore neither can there be plurality or distinction of individuals. Accordingly, whenever this occurs, it is a sign that the form constituting such a nature is not entirely separated from matter and a receptacle, but can be multiplied numerically through its order to diverse matters and receptacles as to the first roots of such multiplication.

This final consequence is evident from the first and from what has recently been said. The first, however, is also clear from both premises. The minor, in which the difficulty lies, can be explained and proved as follows. Diversity of those modes requires that each of those individuals participate in the specific nature in a limited manner, that is, not adequately, and only so far as participation is possible on the part of the mode of participating; otherwise those modes could not be mutually distinct and unequal. But where the specific nature has a being entirely separated from matter, nothing is found from which such limitation can proceed; for since each thing is limited by its opposite, as act by potency, the limitation and constriction of the act—which the specific nature is with respect to individuals—must likewise be effected by an opposite, namely by potency or matter. Therefore neither can a multiplicity of the aforesaid modes be found there. On these matters, see what our Complutensians teach about the limitation of potency by its act in libris Physic., disput. 9, num. 15 and 16, and also what we shall say below at no. 28.

22 It is finally confirmed and explained.

Since being itself, that is, self-subsistent existence, cannot be otherwise than numerically one, because it is entirely irreceptible and consequently unlimited; and therefore, because the divine nature is its self-subsistent existence, it cannot be multiplied numerically. For the same reason, any form entirely irreceptible cannot be multiplied numerically. Consequently, if a form can be multiplied numerically and participates in it inadequately by reason of diverse individual modes of participating in it, this arises from the subject and receptacle on account of which it is limited and constricted, so that it is not had adequately but only insofar as possible on the part of the mode of having it.

This second consequence clearly follows from the first. The first, however, follows from the antecedent, as will be evident to the observer. Hence for this reason the Angelic Doctor often asserts that every individual of the angelic nature has a weakness within its species, and that therefore no other can exist within it. The sense of these words is not that within the range of that species something can be so perfect as to have positively infinite perfection, in the way in which Scotus and others understand the holy Doctor; but only that it has the specific nature in an infinitely negative way with respect to the mode of having it, that is, adequately and without determination to some mode, a mode of participation limited in the manner just described; because it does not have form received in matter. It is proper to matter to be the root of the aforesaid limitation and individual multiplication. Thus, whenever a form is distinguished purely individually from another, such a distinction, and accordingly individuation, cannot fail to proceed from matter and the receptacle as from its radical receptacle.

23 It makes no difference if one objects that specific differences in forms subsisting per se and entirely separated from matter, such as Angels, have a being limited in themselves and are able to limit and contract generic nature; therefore, for the same reason, the aforesaid individual modes will be possible in them, since they are limited in themselves and by their own properties, and are consequently able to limit and determine specific nature even though it is entirely separated from matter. Consequently, in those natures that have form in matter, there will arise no distinction or limitation of individual modes from the matter in which the aforesaid form is received as from the first and radical principle of its limitation and individuation.

The answer is to grant the antecedent and deny both consequences; and the reason for the disparity is this. For the specific differences in Angels can be assigned a sufficient root, or foundation, of their limitation, namely their own actual essence, since it accords with the aforesaid differences that, like the angelic essence, they be formal and actual. With respect, however, to the aforesaid modes, or individual differences, no similar foundation can be given; for it would belong to them to be limited through the mode of matter and potency, as has been shown; and the same specific nature, being entirely separated from matter and therefore not including form receivable in the potency of matter, cannot be the root or foundation of so different a limitation.

This same disparity can be clarified further from the fact that, as we have just indicated, a specific difference in Angels is intelligible as limiting and contracting the generic degree because it restricts that degree through the mode of act and form; and accordingly it can be conceived as received in it and actuating it, as is clear from itself. The mode, or individual difference, however, unless it has material being, derived from matter or the receptacle, cannot be conceived as constricting specific nature; for when it is compared with nature as with act and form, it cannot limit it except through the mode of passive potency, or as its condition, or as something holding itself on the part of matter and the receptacle and deriving its origin from it as from its first root. Thus is preserved the principle that each thing is limited by its opposite, as act by potency, or by something that derives its origin from potency and the receptacle as from the first principle.

§ V. The arguments of the first opinion are refuted except the last.

24 To the first argument, the antecedent having been granted, the consequence must be denied. To prove this, it must be denied that substantial form, as it is this, is most proper to the composite as this, because form is this by reason of matter; and accordingly it is proper to the entire composite by reason of the same matter, as it is this. Thus matter, as this, is most proper to the aforesaid composite insofar as it is this, according to that Aristotelian axiom: That by which each such thing is, is more especially so. Hence the statement made there is false, namely that the very matter which now constitutes one substantial individual can immediately constitute another, if it is understood of first matter, as it is this positively, as will be explained below; in this respect it is the first and radical principle of individuation, even though it is granted that the same matter, as numerically one negatively, but positively diverse, can successively constitute diverse substantial individuals.

25 To the first confirmation, the antecedent must be denied; because existence, being a second and very perfect act, belongs to the composite by reason of form, whereas individuation must belong to it by reason of matter, as has been shown. St. Thomas means neither the opposite of this in the place cited above, but only that the same thing is receptive of existence and is the individual, namely quod, although individuation and purely individual distinction arise from a different root.

To the second confirmation, the antecedent must be denied. To prove this, it must be said that it is one thing for the first principle and root of individuation and purely individual distinction to be an actually first principle, or a principle in actuality, and an actually existing being; but another thing for it to be truly in itself the principle from which individuation itself arises, and finally for it itself to have a true entity, even though it is a principle, and an entity which is potency. We say, therefore, that if we speak properly and in the strict sense, the latter of these belongs to the first principle of individuation, but not the former, as is clear from what our Complutensians assert in 1. ib. Physicor., disput. 3, num. 18, and from what we have noted in this question and shall say below. Hence it is no wonder that the character of the first principle and root of individuation belongs to first matter; and that, for this reason, because it is pure potency and because it does not have existence, from which the reason of being is usually derived, it is called a being in potency, as our Complutensians explain in loco cit. num. 19 and 20.

26 To the second and principal argument, the antecedent having been granted, the consequence must be denied. To prove this, it must be said that form is the first root of the positive specification of matter and of the entire composite, not merely because it completes matter, but because it first gives matter the aforesaid species; since matter, as presupposed to form as precisely giving such specification, is indifferent and has only a negative specific unity. Nevertheless, the same form, as it is this, in the respect in which it could be the root of the individuation of matter, merely completes matter; it does not first give individuation either to matter or to the composite. For matter, as this, determinate and appropriated to this form and composite rather than to another, is presupposed to them as the root of both; because, as we recently said, individuation and purely individual distinction is material unity and distinction, whereas specification and specific distinction is formal unity and distinction. Therefore the former proceeds from matter; the latter, however, must proceed from form as from the first principle.

27 To the third argument, the antecedent must be denied if it is understood of matter as this positively and numerically. For form, as this, is fitted to this numerically individuated matter, as this positively—that is, as determined numerically by this matter or to this matter by quantity—so that it cannot be received in matter which is numerically another and positively individuated. To the first proof to the contrary, the antecedent must be denied when understood of the very same matter as numerically the same and positively individuated, although the very same matter, by identity and negative unity, is under the form of an embryo and afterward under an animal form, for example, a horse, as our Complutensians teach in lib. Physicor., disput. 3, num. 34, and disput. 6, num. 11, and in lib. de Generatione, disput. 5, num. 38. Hence the consequence must be denied in the same proportional sense.

From this, with regard to the second proof, what seems to be presupposed in it must be denied, namely that there is some collection of horse souls that can be received in this numerically individuated matter, as this positively. For although all substantial forms under the lunar heaven can be received in this numerically individuated matter—precisely, as has been said, by negative numerical unity, because all sublunar matter is only numerically one in a negative way—nevertheless, if matter is considered as numerically one positively, any matter, as this, seeks this form and not another; and it cannot regard another unless the aforesaid matter becomes another through a distinct determination to another, diverse quantity.

28 To the confirmation, it is sufficiently clear from what our Complutensians say in lib. Physic., disput. 6, num. 9 and afterward, where they explain how it is not enough for the same man to rise again numerically that the same numerically individuated soul alone be given to him; and in what way matter is distributed among those who feed on human flesh, so that each rises again with his own matter and form.

To the fourth argument, the major is to be granted in accordance with what we have so often indicated, and the minor denied. To prove this, the inference must also be denied. To prove the denial, one must deny that just as matter limits form, so form limits matter—not indeed in the sense that form in no way limits matter, but in the sense that there is complete parity between the two with respect to the aforesaid function. For matter limits form through the mode of potency and of the first subject, which is not receivable in another as in a subject; and therefore the limitation whereby form is limited must be referred back to it as to the first principle, with respect to individual being. This is because the opposite that limits in this manner is adapted to limit another opposite with respect to individual being and purely individual distinction, as is clear from what has been said and will be developed at length below. Form, however, limits in a different way, namely through the mode of act and of communicable form. Thus it cannot limit its opposite with respect to individual being, but with respect to specific being communicable from itself to another, as one superior to its inferior, as will be explained more fully there.

29 Therefore, since in a substantial composite, as we have indicated above, being is limited both according to species and according to number, and since these two are so mutually opposed that they differ according to these two reasons and in the manner just indicated, there must be two limiting principles of different kinds, and two opposites, into which the aforesaid limitation is ultimately referred as into its first root. Accordingly, since these mutually limiting opposites can be only two, namely first act, that is, substantial form, and first potency, namely matter; and one of them, namely first potency, cannot by its limitation be the first root of specific unity, as the Doctors commonly hold, it follows that the limitation of form with respect to matter entails only that the aforesaid form be limited to specific being; and accordingly it remains to matter alone to limit itself to numerical being.

§ VI. The last argument of the first opinion is solved.

30 To the last argument, it must be admitted that each thing is an individual insofar as it is a being and has being. Accordingly, just as the rational soul is not a being, nor has being, dependently on the body as a material cause from whose potency it is brought forth, so neither does it have individuation dependently on the same body, or matter, as a material cause from whose potency it is brought forth. Nevertheless, because the same rational soul, although not brought forth from the potency of matter, is nevertheless, like that soul, an essential part of man, and intrinsically regards matter, not as that from which it is made, but in which it is received; and likewise, although it is not brought forth, it is nevertheless occasioned by the body and matter, as our Complutensians teach in lib. Physicor., disput. 4, num. 20. Naturally, at least, it cannot be created unless occasion is taken from the body, because it cannot exist unless received in it. Accordingly, its individuation is taken as from its first root from the same matter, or body, as from the term of its relation and its pure receptacle and limiting principle, considered per se and as always indispensably accompanying it. Moreover, this same individuation is occasioned by the same body, and naturally, at least, it cannot begin unless occasion is taken from it. Although, because it has absolute being, or being independent of the body insofar as considered in itself, since it subsists per se, its being and individuation, once produced, do not depend on the body as an occasion except with respect to their beginning, not their end. In other words, it does not depend on the body so that, when the body perishes, the soul itself and its individuation also perish.

31 This answer, in each of its two parts, is taken from St. Thomas. The Angelic Doctor taught the first part, namely that the rational soul is individuated through its relation to matter and a singular body, and accordingly from that same body as from the first root and term of the aforesaid relation, in his question on spiritual creatures, art. 9, in these words: It must be said that although the body is not of the essence of the soul, nevertheless the soul according to its essence has a relation to the body insofar as it is essential to it to be the form of the body; and therefore the body is included in the definition of the soul. Just as therefore, it belongs to the reason of a soul that it be the form of a body, so it belongs to the reason of this soul, insofar as it is this soul, that it have a relation to this body.

With respect, however, to the second part, namely that the same rational soul is individuated by the body as by an occasion in the manner just described, the Angelic Doctor taught the same answer in de ente, et essentia, cap. 6, where, speaking of the individuation of the aforesaid soul, he says: Although its individuation depends on the body occasionally with respect to its beginning, because it does not acquire its being individuated except in the body, of which it is the act, nevertheless it need not depend on the body once the body is destroyed. For since it has absolute being, from which it acquired its being individuated, namely from having become the form of this body, that being always remains individuated; and therefore Avicenna says that the individuation and multiplication of souls depends on the body with respect to its beginning, but not with respect to its end.

32 It makes no difference if one says that, just as the rational soul has self-subsistent being with respect to its end, so it has it with respect to its beginning; yet, notwithstanding this, a body is required for its individuation with respect to its beginning; therefore likewise with respect to its end. Accordingly, just as its individuation and being depend on the body with respect to their beginning, as on an occasion, so likewise with respect to their continuance and end; or, if they do not depend on it with respect to their continuance, neither do they with respect to their beginning.

The answer is to deny both consequences; for there is a disparity between the reason St. Thomas introduced in de potentia, quaest. 3, art. 10, namely that the soul was made by creation. Thus he says: Created things are made by God in their natural perfection, for what is perfect naturally precedes what is imperfect, according to the Philosopher, etc. The soul, however, does not have the perfection of its nature outside the body, because it is not of itself a complete species of any nature, but a part of human nature; otherwise soul and body would not become one except accidentally. Therefore the human soul was not created outside the body. Yet, when the soul was once created with its natural perfection, which accrues to it through union with the body, it is not incongruous that it afterward lose that perfection, because it is united to a corruptible body and a union that can be lost, and because it does not fill the entire capacity of matter; hence it can lose this perfection. And because the soul always has self-subsistent being, even after losing that perfection ², it remains with its being and individuation.