Cursus Philosophicus Thomisticus, Secunda Pars Artis Logicae

To investigate the account of the individual, which is quite perplexing, and to explain its definitions, two PRELIMINARY NOTES are needed.

First, we may speak of individuation taken generally, as found in every genus, of substance as well as accident; or specifically, as found in the genus of substance, where individuation occurs in a special way because substance subsists in itself and must be individuated through itself. Thus, although in every individual one can ask both about the principle or foundation of individuation and about individuation itself, in substance there is not only a principle of individuation and individuation itself caused by such a principle, but also a term or completion of singularity by which that nature is made complete and subsistent. A nature can be found without this term and its own subsistence, as is clear in the human nature assumed by a divine person. St. Thomas therefore says in On the Power of God, q. 9, art. 2, ad 1¹, that “in a particular substance three things are to be considered. One is the nature existing in singulars. The second is the mode of existence of such a nature, which exists as proper to this individual. The third is the principle from which this mode of existence is caused.” There he calls singularity a mode of the nature.

Second, the individual or singular, as commonly found in every genus, can be considered either according to first intention or according to second intention. As to first intention, an individual signifies singularity itself as found in reality. This real singularity or individuation is physically and in reality nothing other than numerical unity, by which something is so one that it is undivided in itself and divided from everything else, as St. Thomas teaches in Summa theologiae I, q. 29, art. 4. In reality this numerical unity is like a mode of the nature and makes for unity simply, because specific and generic unities exist by reason, while in reality they are agreements or likenesses and can be divided further into lower things, which numerical unity cannot. As to second intention, an individual consists in two relations of reason. The first is the relation of being a subject of higher predicates, whether the immediate predicate, which is the infima species, or mediated predicates, which are genera, as is clear in generic individuals such as this animal, this body, and so forth. These individuals are taken from the side of their being subjects. The second relation of reason is predicability, by which an individual is predicated not of something lower, but of itself.

In view of these three points, Porphyry’s three definitions of the individual proceed. The first is of the individual taken according to first intention: “Individuals are so called because each consists of properties whose collection will never be the same in another.”

As for which individuating properties these are, Albert the Great’s statement is commonly accepted²: there are seven, contained in this familiar verse:

Form, figure, place, time, with name, blood, fatherland: these are the seven that one person does not share with another.

The enumeration of these properties makes it sufficiently clear that this definition explains the individual according to first intention, since the properties counted here really exist, as is clear of form, figure, and so forth. Indeed, this definition defines only an individual substance, since only substance can possess this collection of properties. More narrowly still, it defines not every individual substance but a complete and subsistent one, called a supposit or person, because some properties belong only to a supposit and not to its parts: for example, a name, which is imposed on the whole person; blood, that is, lineage or generation, which belongs only to persons; and likewise fatherland. For neither a hand nor a foot is said to have a fatherland or to derive its lineage from such blood; the whole human being does.

St. Thomas gives the definitions of an individual taken according to first intention in another way. In Summa theologiae I, q. 29, art. 4, he says that “an individual is undistinguished in itself and distinct from others”; or, better, in Metaphysics X, lecture 11³: “An individual is what is not further divided by either formal or material difference.” These definitions apply not only to substantial individuals but also to accidents. The first can be explained as follows: an individual is undistinguished in itself, that is, one and individual, and distinct from others, that is, ultimately distinct and no longer distinguishable through other differences. The second definition explains this when it says that an individual is not further divided. Just as unity, although it says something positive together with a negation of division, adds no positive thing to being but only that negation—which does not enter into the constitution of entity but pertains to its property—so individuation does not signify anything belonging to a thing’s quiddity, but explains something outside it, as a modification or determination through negation.

BUT IF YOU ASK whether Porphyry’s definition is essential or descriptive, the reply is: descriptive, because it is given through properties whose collection is found in one and not in another. Therefore it presupposes the essence of the individual as already constituted, since properties presuppose that of which they are properties. It is not enough to say that they presuppose the specific nature, because with respect to that nature they are not properties but accidents; otherwise they would belong to everything to which the specific nature belongs. The better account, perhaps closer to Porphyry’s intention, is that the individual is not defined by properties consequent upon and posterior to individuation itself. Perhaps the individual does not have proper attributes founded on a necessary connection with the nature, but rather properties that are the principle and reason for individuation insofar as they designate matter, so that individuation arises from matter thus designated, as will be proved from St. Thomas’s opinion in the books on Generation⁴. Porphyry’s words seem to incline to this when he says that individuals are so called because each consists of properties, etc. He does not say that an individual consists in this, but “is so called from this,” namely because individuation originates from those properties designating matter, which is the principle of individuation. St. Thomas rightly observes in Metaphysics VII, lecture 15⁵, that “a collection of accidents is not the principle of individuation, but designated matter,” because “each form is by its nature apt to exist in many things.” However many forms or accidents are aggregated, they do not individuate. Matter is therefore required, because it is the principle of incommunicability, being the ultimate subject beyond which no communication is possible. Matter is designated by properties, either by receiving them or by having an order to them, especially to quantity; from this results the designation or division of matter, as will be said in the cited place.

IF YOU ASK AGAIN what this individuation is formally, the reply is that the principle of individuation is one thing, and individuation itself, caused by that principle, is another. In things composed of matter, St. Thomas takes the principle of individuation to be matter designated by quantity and accidents, or by an order to them. In things separated from matter, he teaches that form itself, insofar as it is incommunicable to matter, is the principle of individuation. Opinions differ on this, and there is disagreement between St. Thomas, Scotus, and others. Scotus teaches that this individuation comes from some mode added to the nature, which he calls haecceity, by which the nature is made formally this and designable. Others teach that each being is individuated through itself and not through another principle, just as it is one through itself. This controversy need not be treated here, but in the books on Generation, q. 9. See Cajetan, On Being and Essence, ch. 2, near the end.

Formally, individuation itself, caused by the principle of individuation, is metaphysically the individual difference; physically it is numerical and individual unity, by which a being is so one that it is no longer divisible or communicable through other contracting differences, as already explained above and as will be discussed further in the cited place on Generation.

Speaking specifically IN THE GENUS OF SUBSTANCE, there is a peculiar account of individuation, as St. Thomas rightly notes in Summa theologiae I, q. 29, art. 1, because substances are individuated through themselves—that is, without an order to something outside themselves, but by subsisting in themselves. Thus in substances singularity or individuation, which is also found in accidents, differs from subsistence or supposithood. In Christ’s humanity it is certain that a singular nature—that is, a non-universal nature—was assumed, but it did not subsist or have a supposit. Supposithood is therefore something distinct from individuation and is related to it as a term completing the singularity and existence of a nature. Hence substantial individuals have special names: supposits, persons, hypostases, primary substances, natural things, subsistences. These signify an individual as a certain whole and complete thing in the genus of substance, which underlies other things, both the essential predicates of its nature and its accidents. Such terms therefore signify not merely a nature’s singularity, but its complete and subsistent singularity, which we will discuss below, q. 15, and in Physics I, q. 7. Other names are common to individual accidents and substances, whether whole or partial, subsistent or not: singular, individual, particular. The demonstrative pronouns “this,” “that,” “that one,” and similar terms are likewise common, as St. Thomas explains very well in Sentences III, for Annibald, dist. 6, single question, art. 1⁶, and in other Sentences commentaries there⁷, and in Sentences I, dist. 26, q. 1, art. 1⁸. There he also explains how these names are sometimes taken according to first intention, sometimes according to second intention: “individual,” “particular,” and “singular” sometimes designate the reality of singularity, and sometimes the relation of a second intention to higher predicates. We now use these names interchangeably to signify individuation according to either first or second intention.

Thus far we have explained Porphyry’s definition of the individual according to first intention. For the individual according to second intention, Porphyry gives two definitions. The first is from the side of predicability: “An individual is that which is predicated of one alone.” The second is from the side of being a subject: “An individual is contained under a species, and a species under a genus,” thereby showing that it belongs to an individual to be the ultimate subject, as contained under genus and species. Note that being a subject, the relation of an individual as lower to its higher predicates, is the principal thing signified in the individual, because the principal account of an individual is its inferiority to a universal; an individual is opposed to a universal as a lower to a higher. The predicability belonging to an individual, since it is predicability only of one or of itself, is not so much an artificial predication as an identity. Yet since identical predication also belongs to things taken universally, as when one says “A human being is a human being,” or “An animal is an animal,” something must be added for this definition to apply only to the individual: what can be predicated of one only identically and in no other way is called an individual. For although things in common can be predicated identically, they can also be predicated in another way, namely formally of their inferiors, as a formal predicate of a distinct concept.

THE ARGUMENTS ARE ANSWERED.

First it is argued by the common argument that a singular is neither definable nor knowable, since there is no science of singulars. Therefore a definition of the individual is given to no purpose.

If it is said that individuation itself in common is being defined, the objection is: this individuation is not an individual but a universal, for it is predicated of many and not of one alone, since the account of individual belongs to many. This common individuation is either a second or a first intention. If it is a second intention, it does not preserve Porphyry’s first definition, which is of the singular according to first intention. If it is a first intention, it is neither univocal nor definable by one definition, because individual differences are diverse from the outset and therefore have nothing univocal or common.

THE REPLY is that this argument touches on the difficulty to be discussed in the next article, concerning the individual in common or the vague individual, which can be conceived in common. See there the reply to the first argument, where we will show that an individual in common is universally denominated, but is not formally universal.

To the other part of the argument it is replied that individuation taken according to first intention can be conceived analogically in common and thus defined, as will be said in the next article. Taken according to second intention, as a relation of reason of being a subject or of predicability, it can also be conceived univocally in common.

A second argument: When the definition of an individual says, “whose whole collection of properties is not found in another,” this means either properties taken in common or singular and determinate properties. If taken in common, it is false that their whole collection cannot be found in another. The same fatherland, blood, and so forth can belong to many individuals. Likewise, figure and form taken in common belong to many. If taken singularly—for example, this form, this figure, and so forth—the definition first begs the question, since it defines the individual by an individual property, even though this property is individual and singular because of its subject. Further, then it would be pointless to say that the whole collection of properties is not found in another, since not only the whole collection but even one individuated and singular property cannot be in another—for example, this figure, this form, this place, and so forth. For although one extrinsic denomination can belong to many, as one fatherland can denominate many individuals, and one real accident can by divine power be posited in many subjects, by the natural order it can be in only one subject, precisely because it is an individuated and singular accident.

THE REPLY is that the definition is understood of a collection of properties not taken in common but in the singular, since any accident taken in common can belong to many. To the objection it is said that no question-begging occurs, because the individual is not defined by properties insofar as they are individuated and singular, but insofar as they are a principle of individuation: they so designate and determine this individual that they cannot be found in another. Although they can do this only if they are themselves singular and individual, they are placed in the definition not insofar as they are individuated in themselves, but insofar as they are the principle of individuating and making the individual incommunicable to another. The individual’s designation and determination depend on them as conditions. Hence one may also understand how true St. Thomas’s opinion is: the principle of individuation is matter designated by quantity and accidents, not because accidents formally constitute individuation, but because individuation depends per se on matter as its principle and on accidents as conditions of designation. Otherwise it would be pointless to define an individual through a collection of properties, etc.

To the final objection it is said that among these properties of individuation some belong to several individuals, namely those that denominate extrinsically, such as fatherland, name, blood, and place; others belong to only one, such as this form, this figure, and so forth. Hence it was necessary to speak of the whole collection, and not of one property separately, as not being found in another individual.

Finally, it is argued against the definition of a predicable individual: some individuals are predicated of many; therefore the definition is false.

The antecedent is proved: numerically the same matter is in one individual and afterward in another, as in Peter and his corpse; numerically the same action denominates a first and a second cause; the same cognition concerns many known things; the same place contains many things located, at least successively. Finally, numerically the same water can be divided into several portions of water, each of which is one individual. Therefore it is wrongly said that an individual is undivided in itself and not divisible into others.

THE REPLY is that it is not incompatible for an extrinsically denominating accident to belong to many as inadequate and particular subjects, or for one matter or subject to receive different forms, whether simultaneously or successively. But this is not for an individual to be predicated of many numerically distinct things as inferiors, nor for one form to exist in many adequate individual subjects, which is required for an individual to be predicated of many simply and adequately. Thus an accident or form denominating many subjects has them as partial and inadequate, not as wholes with respect to its denomination, although it is true that an inhering form cannot exist in several really distinct and separate things. When water is divided into several portions of water, this does not happen through multiplication and predication of itself, but rather through corruption and division: it ceases to be one individual water, and several arise from it through division. We are not speaking here of this mode of division.