Disputationes metaphysicae

1. Various divisions of one.—Aristotle disputes on this matter, Metaphysics V, c. 6. It must, however, necessarily be set out beforehand in this place, in order that we may be able to explain which unity is an attribute of being. Aristotle, then, distinguishes various modes of one. And his first division is that one kind is one per accidens, another per se. And he deservedly places this division in the first place, because it also seems to be very analogous; for one per se is simply one, but per accidens only in a certain respect, and through a certain proportion to one per se. Aristotle, however, does not explain the notions of one per accidens and per se through their proper definitions, but only by various examples, by which he at the same time proposes various modes of unity per accidens and per se. For he says that the subject affected by an accident is one per accidens, as musical Peter. Likewise two accidents inhering in the same subject are, or constitute, one per accidens, as sweet white. This unity per accidens, however, we can explain in various ways in order to predications, either through incomplex terms, or through complex ones, or by predicating accident of accident, either in common or in the singular. And according to these Aristotle distinguishes various notions of this unity, which pertain rather to dialectical predications than to the metaphysical matter. Similarly Aristotle explains one per se by various examples, or by subdistinguishing it into various modes. For some things (he says) are one by continuation, as a line, water; some by binding together, as a house and other things which are made by art; others by reason of one form; others by reason of matter, either proximate or remote, as liquids (he says) are called one. Again (he says), one kind is one in number, another in species, another in genus, etc., which he pursues there. From all of which it is difficult to gather in what the notion of one per se and per accidens consists; for among the members which Aristotle enumerates in the latter place, many seem to be one only per accidens, as a house and artefacts. Likewise he says in the same place that several things are sometimes called one because they do, or undergo, or have, or are related to, some one thing. But all these seem to be one only per accidens, or by denomination rather than in reality. Again, among the unities which he posits there, some are real, as the numerical, others only of reason, as the generic and specific; it is therefore difficult to reduce this doctrine of Aristotle to some certain notion and method.

The division of being and of one into per se and per accidens is explained

2. In order, then, to declare this matter, since one follows upon being, in order that it may be understood what one per se and one per accidens are, it must at the same time be explained what being per se and per accidens are; for being too is so divided by the same Aristotle, in the same Book V, c. 7; which division is proper to real being; for beings of reason, as they are beings only equivocally, so they do not receive these denominations except equivocally. Real being, however, can be called per se or per accidens in two ways: in one way in the notion of being, in another way in the notion of effect. In this latter way that is called per se which comes about from the power and intention of the agent; but that is called per accidens which happens beyond the intention of the agent by chance and fortune; of which Aristotle says, Metaphysics VI, c. 2, that it is outside the consideration of science, namely in so far as it is exercised in the singular and per accidens, for as such it does not have necessity, but contingency. But the very common notion of cause or effect per accidens does fall under science; for so one disputes about chance and fortune and the contingency of effects; but nevertheless being per se and per accidens under this consideration pertains nothing to the present purpose.

3. What kind of one per se and what kind per accidens Aristotle indicates.—In the former way, then, being in the notion of being is called per se or per accidens in order to the unity which it has, or by reason of such unity; as, for example, because it consists of one nature of one predicament, or of natures of diverse predicaments; for so Aristotle, in the said Book V, texts 13 and 14, calls those things beings per accidens which consist of subject and accident, or when many accidents are conjoined in the same subject; but he says that that is being per se which is divided into the ten categories. And the same Aristotle, Metaphysics VII, text 43, and more clearly Book VIII, text 15, and De Anima II, text 7, indicates that that is being one per se which either is simple, or is composed of substantial potency and its proper act. Whence conversely that will be per accidens which is neither simple nor has the aforesaid composition, but consists of diverse things in another more imperfect mode. From which it may be understood that that is called being per se in the notion of being which is one per se; but that per accidens which is one only per accidens. For per se and per accidens are not here so called by reason of the mode of being per se or in another, in which way substance alone is being per se, while the others can be called per accidens, or rather accidental; but per se and per accidens are taken in order to unity; but what unity per se or per accidens in beings is has not been sufficiently declared from what has been said, nor is it explained in the same way by all.

4. Simple existence is not of the notion of one per se.—Some, then, say that that unity or union is per se from which one and the same being results, but that that is per accidens in which the beings which are united have several beings, as are substance and accident, or two accidents of diverse genera. But this explanation either supposes something false, or explains an obscure matter by another equally obscure; for either the discussion is of one simple being without composition which is in it, although it results from composition, in which way many say that from matter and form united one being results, and this sense supposes something false; for in order that being be one per se it is not necessary that it have a simple being of this kind; for below I shall show that beings composed of matter and form do not have a simple being, but a composite one. Or the discussion is of one composite being resulting from the union of several partial existences, and this indeed is true, but of that very being it remains to be inquired when from composition one per se results; for even an accident, for example whiteness, coming to a substance brings with it its own being, which with respect to the white composite can be called partial, and from it and from the being of the body or subject one being of the whole white thing can be said to be composed, and yet it is nevertheless said to be being per accidens.

5. How one per accidens comes about from two beings in act; but how one per se from one in potency and another in act.—In another way, then, it is frequently wont to be said that being per accidens is that which consists of several beings in act, but that that is per se which consists of being in potency and its act; for from several beings in potency nothing can consist, and therefore it is not necessary to adjoin that member. But this doctrine too, granted that it is true, needs exposition; for, badly understood, it can be the occasion of erring in many things. For it must be asked what is understood by being in act and in potency. For by being in act can be understood that which of itself has actual entity or existence; but by being in potency that which has no such actuality or existence. And in this way it is false that being per se cannot be composed of actual partial entities, or that it is required for being per se that it be composed of such act and the potency opposed to it; for this is the same as if it were said that being per se is composed of being and nothing, or of being in act and being in objective potency, which is a contradiction in terms, as will be evident from what is to be said below. Otherwise, then, by being in act can be understood being consisting of some formal act and the potency receptive of it. And in this way it does not happen that something is composed of two beings in act, so that each is composed in the aforesaid way, except either by aggregation, and then it is sufficiently clear that being per accidens arises, although its notion has not yet been sufficiently explained; or in some artificial mode; and then Aristotle seems to call such a being one per se, whence it consequently is also being per se and not per accidens. And in the physical and heterogeneous composite many think that there are partial composites of diverse notions and forms, from whose conjunction one per se coalesces. And next it remains to be explained, if to a being of this kind another is adjoined not similarly composed, nor after the manner of continuation or binding together, but simple after the manner of a form or act truly and physically united, why being one per se does not result from both. Or if it sometimes results and sometimes not, whence the reason is to be taken. Where various questions are indicated which depend on this, namely, why, when subsistence comes to a nature already integral, one per se results from both, but not when quantity or another similar form comes. Likewise, why the substantial form makes one per se with bare matter, but cannot make one per se with matter already informed by a substantial form, and similar questions.

The notion of being and one per se

6. In this matter, then, it seems it must be said that the notion of being per se consists in this, that it has precisely the things which are required per se and intrinsically for the essence, integrity or completion of such a being in its genus. Aristotle indicated this in the former place cited. And from the terms themselves it seems clear; for these most common and most simple things can scarcely be proved otherwise than by explaining the notions of the terms. Since, then, that is called being which has entity or essence, that will be properly and rigorously being per se which has one essence or entity. But that essence or entity will most properly be one which in its genus has whatever pertains to its intrinsic notion or consummation; therefore that being which is of this kind will under that notion be properly and per se being; but everything which falls short of this unity will be called being per accidens.

7. This, however, can be explained more fully if we divide being per se into simple and composite, which division can also be given of one per se, and Aristotle indicated it, Metaphysics X, c. 6, saying that one kind of one is divisible, another undivided. For, as St. Thomas noted, I, q. 6, a. 3, and q. 11, a. 1, of one per se one kind is undivided in act and potency, another only in act; the former is simple being, the latter composite. Of the simple, then, there is no difficulty; for every simple thing is being per se and one per se, because it is both undivided per se, and as such does not have the admixture of something extraneous so that it could be called being per accidens; and in this way any accident taken in the abstract is by that consideration being per se, and the soul in the notion of substance is being per se, although incomplete; but in so far as it consists of several powers, habits or acts, it already declines into being per accidens.

8. Of composite being, however, it is certain first of all that it can truly and properly be being per se and one per se, as all philosophers teach of substantial nature in so far as it consists of matter and form, and of the supposit in so far as it is in its own way composed of nature and subsistence. For since neither matter nor form are per se complete and integral beings in their genus, but have been instituted by their nature for composing it, that which is proximately composed of them is deservedly called, and is, an essence and nature one per se. And by the same reason, because that essence does not have intrinsic completion in its genus unless it is per se intrinsically and substantially terminated, therefore it too with its subsistence constitutes being one per se. This unity per se, then, consists in this, that it results from things constituting a complete being in some genus, a union intervening between them accommodated to constituting such a being, which in the composition of one nature is after the manner of substantial act and potency; but in the composition of one person it is after the manner of an integral nature and its term. And this reason can also be accommodated to beings as composed of genus and a difference per se contracting it within the proximate predicament; for genus and difference too are compared as potency and act ordered per se to constituting one complete and integral thing in its genus, although this composition is rather rational than real, and therefore can less impede the real and per se unity of being.

9. Besides these, however, there is another mode of composition in beings, which is called from integrating parts, which is first seen in quantity, but through it is understood also to be in material substances and accidents; and this too does not take away unity per se when it is through true and natural continuation. For so continuous quantity is properly and per se one in its genus; but the parts of which it consists are not said to be simply several in act, but in potency, as Aristotle often says, Metaphysics III, c. 6, and Metaphysics V, c. 13, where he says that number properly is only where the parts are not joined by a common term. And Averroes says the same, De Anima III, text 23. And the reason is that quantity by its nature postulates this extension and composition, which is wholly ordered to its completion in its genus, and therefore within it it has proper terms by which its parts can be joined and terminated. That whole composition and union, therefore, is per se and by its nature ordered to composing one being within the same genus. And although this belongs per se primarily to quantity taken according to itself, it nevertheless belongs also to material substance, which underlies quantity, as is seen first of all in homogeneous substance; for fire, water and the like are one per se even if they are taken in any magnitude whatever, provided they are continuous; otherwise a substance of this kind could never be one per se, because it can never not consist of these parts, even if it is taken in the least quantity, which is against all philosophers and against the common mode of thinking and speaking, and against the reason given above, because these beings by their nature postulate this kind of union and composition for their completion and integrity in their genus; therefore such composition does not take away unity per se in beings of this kind.

10. It is necessary, however (although this is to be treated more fully below), to notice briefly here what substance has from quantity in this kind of composition, and what substance itself has from its own substantial entity, although under quantity; for in the former way from substance and quantity one per se, as we are now speaking, is simply not made, because quantity is not of the completion of substance within the notion and breadth of its genus, and therefore quantitative integrity, as it is adjoined to substance and makes one with it, does not constitute being nor one per se. But material substance under quantity has its own substantial entity, in which it also has entitative parts composing and integrating the substantial entity itself, and having among themselves their substantial union; and in this way we say that substance so composed is one per se.

11. This, however, has some difficulty in heterogeneous substances, because their parts do not seem to be so intrinsically united and continued, but only bound together as it were by certain bonds. But nevertheless this substance too as so composed is one being per se. For who would deny that man is one being per se? And a posteriori this can be declared, for all parts of this kind serve one another, and separated per se they either cannot be preserved at all, or not for long; it is therefore a sign that they are all incomplete beings in their genus, and are ordered per se to composing some being; therefore that as so composed is being per se and one per se. Whence for this it is enough that those parts naturally have some conjunction and connection, whatever it may be; for it suffices that all can be informed by the same form, and agree to constitute with it one being having one being simply. Add that, although these heterogeneous members are not on every side immediately continuous with one another, they nevertheless always have continuation on some side, at least in some third thing, as in a nerve or other similar part, of which elsewhere.

12. From these things, then, an induction having as it were been made, it is sufficiently evident how in all substances being one per se consists in the notion explained by us. But almost the same induction can be applied to accidents; for of quantity it has already been said; but others, if they are altogether simple according to the thing, evidently have unity and indivision per se; but if they are composite, in order to make one per se they must in some way imitate quantity. For only a twofold composition can be understood. One is after the manner of extension, in which way there is one whiteness which is extended in the surface of one body; and this composition makes one per se after the manner of an integral whole. For the parts of that whiteness are so related that within their genus they are bound together and united in a mode proportioned to themselves and constitute one complete and integral being in their species; which composition and union those parts have under quantity or in quantity; yet they do not have it intrinsically and formally through quantity itself, but through their partial entities united among themselves by a proper bond and union of their genus. Which can be explained by this reason; for, if in a continuous surface of the same body, for example of a wall, half the part is white and half black, whiteness and blackness have indeed a certain continuity on the side of the subject, because the surface in which they inhere is also continuous, and nothing can be marked in it, however indivisible, which is not affected by whiteness or blackness; and nevertheless whiteness and blackness do not have among themselves the intrinsic union and conjunction which two partial whitenesses have among themselves; and therefore from them one is not made per se and properly, as it would be made from parts of whiteness; which same thing it is probable can happen in its own way in substances, if it happens that under the same continuous quantity there are substantial forms of diverse species under diverse parts of the quantity, as St. Thomas noted, In Metaph. V, text 7, lect. 7, letter D. Another composition in accidents can be after the manner of intension, supposing that the degrees of intension are in some way distinguished in the thing; of which elsewhere. And this composition, although, speaking per se, it does not come about in quantity or through quantity, is nevertheless to be understood and explained through proportion to it. Whence from such composition too one per se results, because all those degrees are as it were partial and incomplete beings within their genus, and by their nature are ordered to completing one thing within the same genus, and have among themselves a natural union and proper terms by which they may be joined or terminated. Therefore in accidents too the notion of being or of one per se consists in the aforesaid notion explained by us. But if perhaps in accidents another mode is found of making one out of many beings besides those mentioned, as in quantitative number, or, according to the opinion of some, in the habit of science, which arises from the collection of many species or habits, those are to be judged beings not per se but per accidens, in the proper and true notion of being, as Fonseca rightly taught, Metaphysics V, c. 7, q. 5, sect. 2, because they do not have among themselves any true and real union through which they would effect one per se, whatever may be the case whether under some predicamental notion they can be judged per se, of which below, in explaining the individual predicaments.

The notion of being and one per accidens

13. From the things which have been said of being and one per se, it may be gathered what must be said of being and one per accidens, which is distinguished from it; for first of all everything which consists of distinct things without physical and real union of them among themselves is rigorously being per accidens and not per se. It is proved both from what has been said, because in such a being the notion of being per se explained by us cannot be found; and also because that one cannot have one real essence; for one essence cannot be understood unless either because it is simple, or because it arises through the real union of many; but in the aforesaid case neither of these is found. Next, every being which is so one that it consists of distinct things, of which one is a complete being in some genus and through the adjunction of the other is perfected by a perfection of a diverse genus, such a being too is rigorously one per accidens, because the notion of being per se explained by us does not belong to it, nor can one true essence be found in such a being. Likewise because, by the very fact that one being is complete and integral in its genus, what is adjoined to it comes accidentally, and therefore it is said to compose one per accidens with it; and by this reason that which consists of things of diverse predicaments and diverse from the nature of the thing is truly said to be one per accidens. Rather, even in things of the same predicament this holds true, if they are of diverse genus or species, and one happens to the other in its notion and species already complete; and in this way from a potency and a habit, or an act, one per accidens comes about; and similarly a gilded silver vessel is being per accidens, and so of the others.

14. Secondly it is gathered from what has been said that in being one per accidens there is variety, and in it more or less. For one is being altogether by aggregation, in which many beings, integral and perfect per se, are heaped together without any union and without any order; and this seems to be most of all per accidens, because on every side it is opposed to being per se properly taken; and of this kind is a heap of wheat or of stones. But another is being per accidens consisting indeed of beings integral per se, not having physical union among themselves, but having some order among themselves, as is an army, a commonwealth, a house, and other similar artefacts, in which there can be as great a variety and as great a difference according to more and less as there can be greater or lesser union between the beings per se of which it consists; and in this way a tree into which a branch of another species has been grafted seems more one than a house, and a house more than an army; and so of the others. And in this order are to be placed mixed liquids, composed of simple ones imperfectly altered, as watered wine, oxymel, etc. Whence it also comes about that, although these are simply and absolutely beings per accidens, nevertheless respectively, that is, in comparison with that being which is one by mere aggregation, they are sometimes wont to be called beings per se. For, because intermediate things participate something of the extremes, in comparison with them they are wont to be called by diverse names; but beings of this kind agree in some way with beings per se, in so far as they are united in some form or relationship, and therefore they are sometimes so named. In which way Aristotle seems to have spoken in the cited place of Metaphysics V. Nevertheless, by this consideration and comparison, being composed of substance and an accident inhering in it seems much more able to be called being per se; for this is the third genus of beings per accidens, which seems to depart more from that first and lowest being by aggregation, and to approach more to one per se, because both the things of which it consists are not distinguished in supposit, as in the others, and they have among themselves a greater physical union, and one is truly in potency to the other, although an accidental potency, and the other by its nature is ordered to the other, and in union with it has its connatural perfection; in all of which such a being imitates that which is properly and per se one, although simply and absolutely it is one per accidens.

Of one simply and in a certain respect

15. Thirdly, from what has been said the other divisions of one are easily explained. For one kind can be called one simply, another in a certain respect. That is properly and rigorously called one simply which is one per se; but all the others can be called one in a certain respect; which seems manifest from the terms themselves; for being one per se is so called because it has unity simply and absolutely; but the others, because they depart from this unity, are called per accidens. This is evident also from the definition of one; for it is being undivided in itself; that, therefore, which is undivided simply will be one simply; but what is simply divided in itself, and has only some indivision in order to some end or to some form, will be one only in a certain respect; and so it happens in those things which are one only per accidens, as is evident from what has been said. Otherwise Gregory, In I, dist. 24, q. 1, and other nominalists there say that only simple being is one simply, because, in order to be one simply, it is necessary that there be nothing in it which is not itself; but this definition has been gratuitously devised by them, and according to it God alone would be one simply. Likewise it is repugnant to Aristotle, Metaphysics X, in the place cited, who distinguishes one into the indivisible and the merely undivided. For it conflicts with the common mode of conceiving and speaking; for being, although composite, is called being per se and simply; why, then, would it not also be called one simply? Likewise such a being is not many simply; therefore it will be one simply, because these two are opposed immediately and as it were contradictorily. Finally, by this reason the theologians teach that Christ, as composed of God and humanity, is one simply.

16. Here, however, two things seem to be observed: first, that it is one thing to say that some thing is one simply or in a certain respect, another that two things are one, in the way in which soul and body are said to be one humanity, or several men one. We are here speaking in the former way; for that is proper and absolute, that is, according to the absolute consideration of being and one according to which notion one is an attribute of being, and not according to the comparison or relation of one thing to another; indeed not even according to a comparison of reason of the same thing to itself, because, as I was saying above, this relation of reason of identity is not of the notion of one, which is absolute. But the latter manner of speaking, in order to be true, must be not so much formal as causal, as is evident in the said examples; for matter and form properly and formally are in truth not one, but compose one; and similarly several men are not so much a people as compose one people, and so of the others; and so that unity which is found in many, whatever it may be, supposes first according to reason some being constituted from them, which is proximately and immediately denominated one; and in this sense is to be understood what is wont to be said, that several things simply are one in a certain respect, as we shall touch on again in the following section.

17. Secondly it is to be observed that the discussion here is of the unity of the thing and not of the unity of reason; for the unity of reason (since it is not in things, but from the intellect) is properly not comprehended by the division posited; if, however, anyone wishes to reduce this unity to the said division, this will be unity most of all in a certain respect; and of this kind is the unity of genus, species, etc., in so far as it is effected through the comparison and denomination of the mind; which can also be greater or lesser in its order, according as it includes greater or lesser indivision according to reason, or according as it is founded in a greater or lesser agreement found in those things. But whether this foundation which precedes in things deserves the name of unity, we shall say afterwards.

18. And hence further the other terms which some use remain explained, as may be seen in Fonseca, in the said q. 5, sect. 6, namely that one is sometimes said of something absolutely, sometimes comparatively, as what is one with itself, or one with Peter in the notion of man or animal, etc. Likewise, that sometimes something is called one in itself and according to its proper notion, as Peter is called one in number; but sometimes something is called one in a superior or inferior notion, as animal in the notion of living thing, or in man. But these in truth are improper, for one is properly said only absolutely; but that comparative unity is not unity according to the thing, but either identity according to reason, or likeness founded in some unity, or certainly it is unity according to reason. And similarly no being is properly called one except according to its proper notion; for according to a superior or inferior notion something is not called one, except perhaps secondarily and by reason of another.

19. Finally it is necessary to note that some unity can be considered in things which belongs to being by reason of its entity, or in it precisely considered; but another unity can be understood belonging to one being through another being adjoined to it; as, for example, in matter (as we were saying above), let us understand entitative unity, belonging to it in its entity and by virtue of it, even if it is precisely considered and separated in the mind from quantity and from any other accident; but another unity is understood in matter by reason of quantity, from which it is called one quantitatively or numerically; and the same can be considered in whiteness and in other corporeal beings; for in immaterial ones only the former mode of unity is found. The unity, therefore, immediately belonging to entity by itself can be called unity per se, not in the sense in which we spoke above of being and one per se, but as per se is distinguished against through another; which mode of unity is found in every being in the way in which it is being, so that even being per accidens, in the way in which it is one per se and not through another, has that unity; and therefore this is the unity which belongs per se to being as being; and to remove equivocation it could be called intrinsic or entitative unity; for the other unity, which belongs through another, is accidental and as it were extrinsic, or denominative, of which more in the fifth section.