Disputation 5, Section 6:

• I. Summary of the position (n. 1)

• "From what has been said thus far against the above positions, it seems that what remains, on the basis of a sufficient enumeration of the parts, as it were, is that the whole singular substance does not need any other principle of individuation in addition to its own entitas or in addition to the intrinsic principles from which its entitas is constituted. For if such a substance is, physically speaking, simple, then it is an individual of itself and by its simple entitas. On the other hand, if it is composed out of, say, matter and form united to one another, then just as the principles of its entitas are matter, form, and their union, so too those same principles, taken as individuals, are its principles of individuation, whereas those other substances, because they are simple, will be individuals by their very selves ...... Hence, just as individual unity cannot formally add anything real and positive over and above individual entitas--since on this point its notion is the same as that of all the types of unity--so too the positive foundation of this unity as regards the negation it expresses cannot add anything positive, physically speaking, to that entitas which is denominated as one and as an individual. Therefore, that entitas is through itself the foundation of this negation, and it is in this sense that the entitas is said by the opinion in question to be by itself the principle of individuation. For this opinion does not deny that within this individual entitas the common nature can be conceptually distinguished from the singular entitas or that the individual adds something conceptually distinct over and beyond the species--something which, according to a metaphysical consideration, has the notion of an individual difference ..... However, the present opinion adds that this individual difference does not have within the substance any principle or foundation that is in reality distinct from the substance's entitas, and so in this sense it claims that each entitas is a principle of its own individuation through itself ... In order for this to become clearer, we will explain it case by case for all substantival things."

• By `substantival things' Suarez means all the intrinsic components of a material substance, viz., its individual primary matter, its individual substantial form, and the individual mode which is the unity between this matter and this form. The rest of this section is taken up with this discussion, with a brief discussion of immaterial substances at the end.

• II. The individuation of primary matter (nn. 2-4)

• A. The claim

• "The matter is in reality individual and the ground of this unity is its entitas through itself, insofar as it exists in reality without anything extrinsic added to it."

• B. The argument

• (1) This matter (say, of a stick) is distinct from that matter (say, of a human being); therefore, it is individual and singular in itself.
• (2) But the ground of this unity in it is neither the substantial form or any relation to the substantial form, as was proved above (for it remains numerically the same matter under any form it might exist under).
• Therefore, the ground of this unity is its own entitas.

• Suarez goes on to claim that this is true even on the assumption that each matter always has a particular quantity. The quantity would still be separable from it, at least by God's power, and, besides, the quantity would be extrinsic to its entitas and thus presupposes the latter. Furthermore, the same argument holds for other dispositions or accidents besides quantity. The agent acts on the matter qua individual, and so presupposes it in its individual unity. It is true that the agent limits the matter to this form either by removing impediments to the reception of the form or by giving it dispositions that are naturally necessary for the introduction of this form. But all of this presupposes the matter's prior existence as an individual.

• C. Objections and replies

• Objection 1: Since matter is pure potentiality, one matter is made actual and hence distinct from another matter only by some form or actuality. Hence, it is not an individual by itself.

• Reply: It is only with respect to position that quantity makes one matter distinct from another. But each matter is entitatively and really distinct through its own entitas, since "matter of itself has some entitas, be it entitas of existence or entitas of essence."

• Objection 2: Matter is, by its species, essentially related to form; therefore, this individual matter is individuated by the form or by its relation to this form.

• Reply: "Just as matter has a transcendental relation to form, so too this matter has this sort of transcendental relation to form, since it has numerically this capacity and potency, and in this sense it is individuated by its relation to form. But this is just what it is for it to be individuated physically through itself, since its entitas essentially includes this relation. It is not necessary, however, that this individuation be effected through the determination of the form, since it is not only matter as a species but numerically this matter that is related to form in general."

• III. The individuation of substantial form (nn. 5-13)

• A. The claim

• "The substantial form is a this intrinsically through its very own entitas, from which the individual difference is taken in accord with the form's ultimate grade or reality."

• B. The argument

• (1) No accidents can be principles that individuate the substantial form. (The reasons here are already familiar to us, both as regards the substance's accidents and as regards the accidents of the matter leading up to its being informed by the substantial form.)

• (2) Matter cannot by itself be an intrinsic principle that individuates any substantial form. (The reason is that the matter is not an intrinsic principle of the form's entitas. The matter is at most a sustaining cause of the form, but a sustaining cause is extrinsic to that which it sustains. So matter causes the individuation of form only in the sense that, in the case of material substances, it provides a necessary condition for the existence of the form.)

• C. Addenda

• The question arises about whether in general a given form can exist in just any primary matter, or whether it essentially informs this matter which it in fact informs. Thomists generally accept the second view and then go on to say that in the case of the form, its individuator is the matter even though the matter is extrinsic to its essence.

• Suarez points out, first, that this cannot be true of the rational soul, which is conceived by all to have a certain independence of its matter in the sense that it actualizes distinct matters, both synchronically and diachronically. Suarez seems to assume that this is not generally true of sentient and plant souls (see n. 9). (There are, to be sure some, difficulties here, but I think he's wrong about this. For he clearly thinks that change of material parts entails change of form, since such forms are said to be extended and divisible. This accounts for his somewhat puzzling remark above that the unity of a tree or brute animal over time is not unity of the composite in the strict and philosophical sense.) Nonetheless, even in these latter cases he denies that the matter can be deemed a principle of individuation for the form, since no such disposition to a particular form can be thought of as existing in the matter.

• IV. The individuation of substantival modes, especially the union of matter and form (n. 14)

• A. The claim

• "A substantival mode, which is simple and in its own way indivisible, also has its own individuation of itself and not from any principle that is in reality distinct from it. This will be explained by examples in the case of the union of form with respect to matter, or of matter with respect to form, which I am assuming to be a substantival mode; likewise in the case of simple subsistence."

• B. Comment

• As Suarez conceives of such union, it is always the individual union of this matter with this form. Thus a change in either term results in a numerically distinct union. Yet the union itself is, according to Suarez, distinct in reality (modally distinct) from the form and from the matter. What's more, it's at least conceivable that this matter and this form should be united by a different union. Suppose, for instance, that God separated them and then reunited them; he would not have to effect numerically the same union.

• V. The individuation of the substantival composite (n. 15-17)

• A. The claim

• "In a composite substance, insofar as it is such a composite, the adequate principle of individuation is this matter and this form as united to one another; among these, the principal principle is the form, which is by itself sufficient for the composite, insofar as it is an individual of such-and-such a species, to be judged numerically the same.

• In reply to Fonseca's claim that this way of speaking is true but inappropriate, since the matter and the form are not added to the common nature in order to form the individual composite, Suarez has this to say by way of clarification: "In these arguments he moves away from a physical notion to metaphysical composition. For when this matter and this form are called physical principles of the individuation of this composite, they are being related not to the common specific nature, but to the physical composite that they compose. Therefore, it is necessary not that they be added to the common specific nature, but that they compose that nature by composing an individual in which that nature is included. Hence, according to the same physical constitution such principles are simples; nor do they have any other principles by which they are physically individuated. Rather, they are individuated by themselves, as has been explained. Thus, it is not an improper way of speaking, but a true and proper one, since the intrinsic principles of individuation are the same ones that are the intrinsic principles of entitas, as has been said over and over again. For individuation follows upon entitas insofar as it is a certain negation; on the other hand, insofar as it is something positive, it adds nothing to the entitas. But this matter and this form, united to one another, are the intrinsic principles of the entire entitas of the composite substance, of which we are now speaking. Therefore, they are also the intrinsic physical principles of individuation .... Neither [form nor matter] by itself, but rather both together, are the adequate principle [of individuation]. For this composite, in order to be numerically the same wholly and completely, requires not only this matter or this form but both together, and if either of them is varied, then it does not remain numerically the same composite, in an unqualified sense and in every part, that it was before, since to some extent its entitas has been changed. "And from this it is clear that numerically this same union is also required for the perfect unity of such a composite, since in its own way this union contributes to the constitution of the composite. However, the union is not as necessary as the matter and the form, since they are essential principles of such a composite in an unqualified way, whereas the union is a sort of necessary condition, i.e., it is the causality of the matter and the form. "Also, if we compare the matter and the form to one another, then the principal principle is the form--not only with respect to the specific nature, taking the form insofar as it is in a species, but also with respect to this individual, taking the form as an individual. For this form is maximally proper to this individual, and it is that which completes numerically this whole substance ... Consequently, the form is the principal principal that distinguishes this substance from others."

• All of this raises interesting questions about identity through time. What are we to say? Suarez clarifies his position a bit by talking about how the subsistence of a substance fits into this picture: "Just as the difference must be taken from a substantival, and not an accidental, principle, so too among the substantival principles it should be taken from the one that is the principal one and the one that is more proper and the last constituent of the thing itself. But form is like this, as has been shown. This is likewise true if we are talking about the individual of such a nature or species insofar as it is formally constituted in that species. It is for this reason that we claimed above that a suppositum is numerically one as long as it has numerically one subsistence--even if the nature is not one. For the formal constituent of the suppositum is the incommunicable subsistence, from which alone the notion of an individual suppositum as such must be taken. By contrast, however, we claimed that the unity and individual difference of a singular thing, insofar as it is constituted under such-and-such a species or substantival essence, must be taken from the substantival nature, which formally constitutes such an individual. This is the sense in which we are now claiming that the individual difference of this human being, taken formally insofar as it is an individual of the human species, is taken from this soul. On the other hand, if we are talking of this composite, insofar as it is perfectly and in all parts one, then it will be more accurate to say that the individual difference is taken from its whole entitas and so from its adequate physical principle, which includes the matter and the form--and this in order that it might be true of the whole composite as well that it is individuated by itself, i.e., through its own entitas."