Philosophy Essay - Critical Essays




Major Works

Aristotle's Metaphysics deals with what he referred to as "primary philosophy" or "first principles." The field of metaphysics studies cosmology and ontology, and in Aristotle's Metaphysics, both areas are investigated through an analysis of the nature of being. Cosmology is concerned with the origin and nature of the universe, and ontology with the nature of existence.

Aristotle refers to the philosophical inquiry into ethics and politics as "practical science," as it is concerned with the individual's actions. His Nicomachean Ethics, often referred to simply as the Ethics, offers a close study of Greek ideals, of the notion of "the good" and the best way of life, of the nature of virtue, and of social problems and conflicts. The shorter Eudemian Ethics covers similar material but with different emphases. Politics approaches political science from the viewpoint of the state, or city-state. Consisting of eight books (the order of which is still a matter of debate), Politics covers such topics as the nature and structure of the state and of society, civic virtue, education, and class roles and distinctions.

Textual History

Little is known about the fate of Aristotle's works after his death. It is believed by some scholars that for about two hundred years the works were either lost or hidden. They were discovered by Sulla (178-38 B.C.) and brought to Rome. Modern editions of Aristotle's works derive from Roman editions dating back to the late first century B.C. In the Middle Ages, Latin and Arabic translations broadened the influence of Aristotle's teachings and his philosophy was studied extensively by St. Thomas Aquinas (c. 1225-74) and later by Francis Bacon (1561-1626). As relatively few of Aristotle's works can be dated with any degree of accuracy, the focus of nineteenth- and twentieth-century scholars has been on determining the chronological order of the works.

Critical Reception

Modern criticism of Metaphysics has focused on Aristotle's intended meaning, as well as on the identification of, and attempts to resolve, apparent inconsistencies within the text. Joseph Owens has discussed the various interpretations regarding the nature of being made by medieval metaphysicians, noting that there are two distinct ways in which this doctrine may be understood. Owens has observed that medieval Christian thinkers attempted to unify these two concepts; he has also presented the views of later critics who either attack or support such a unification. Franz Brentano has examined a different aspect of the nature of being, studying Aristotle's analysis of "potential" and "actual" being. Brentano has pointed to some apparent difficulties with the definitions Aristotle provides, and has offered an interpretation which elucidates the two concepts and the relationship between potential and actual being. The concepts of substance and form as Aristotle presents them in Metaphysics have also generated much criticism. Wilfrid Sellars and Richard Rorty have both approached these issues, but from different angles. Sellars has noted the ways in which Aristotle's Categories (discussed in the Science section of this volume), particularly the theory of predication found there, can aid one's understanding of the nature of substance, form, and matter as presented in Metaphysics. Rorty has argued that, by giving more credence to Aristotle's claim that genus is matter, the difficulties encountered when studying substance and form are reduced.

The most salient issues for modern critics with regard to Ethics have included Aristotle's doctrine of "the good" and the related issue of happiness—"the good" being the single end at which one aims throughout one's life, and happiness being a result of that quest. W. F. R. Hardie and Daniel T. Devereux have addressed the critical debate concerning the nature of the good and whether Aristotle views it as a dominant or inclusive end. Hardie has asserted that Aristotle presents the final good as dominant, but that the philosopher at the same time suggests its inclusive nature. Hardie has concluded that the doctrine of the good focuses on the power of man to "reflect on his own abilities and desires and to conceive and choose for himself a satisfactory way of life." Devereux has asserted, however, that the issues of dominance and inclusiveness are far removed from Aristotle's views on the subject of the good. Devereux has stated that the Ethics outlines two different types of happiness, both of which are "implicitly inclusive." Perfect happiness, Devereux has noted, is associated by Aristotle with a life of philosophical contemplation, and a secondary degree of happiness may be achieved through a life of moral virtue. Aristide Tessitore has also stressed Aristotle's proposition that perfect, complete happiness can only be found through philosophic contemplation. Yet Tessitore has emphasized as well that Aristotle encourages a life of virtue for non-philosophers by linking them, through the concept of moral decency, to philosophers.

*Principal Works

Ethica Eudemia [Eudemian Ethics] (philosophy)

Ethica Nicomachea [Nicomachean Ethics] (philosophy)

Metaphysica [Metaphysics] (philosophy)

Politica [Politics] (philosophy)

*Since the dates of Aristotle's treatises are unknown, his works are listed here in alphabetical order.

Principal English Translations

The Works of Aristotle Translated into English [edited by J. A. Smith and W. D. Ross] 1910-52

Aristotle's Eudemian Ethics, Books I, II, and VIII[translated by Michael Woods] 1982

The Politics [translated by Carnes Lord] 1984

Aristotle: Nicomachean Ethics [translated by Terence C. Irwin] 1985

Primary Philosophy

Franz Brentano (essay date 1862)

SOURCE: "Potential and Actual Being," in On the Several Senses of Being in Aristotle, by Franz Brentano, edited by Rolf George, translated by Rolf George, University of California Press, 1975, pp. 27-48.

[In the following essay, originally published in 1862, Brentano discusses the nature of potential and actual being as analyzed by Aristotle in Metaphysics. Brentano examines Aristotle's definitions of potential and actual being and presents readings of them designed to resolve some difficulties within them. Finally, he explores the relationship between the two concepts, maintaining that "movement is the actuality of the potentiality."]

The two senses of being …, namely, being which is divided into the categories and potential and actual being, belong together and are intimately connected with each other.1 Thus they have in common that the science of being, metaphysics, is concerned in the same way with one as with the other,2 while, as we saw, both accidental being and being in the sense of being true were excluded from it. Since being, as the most general, is asserted of everything,3 it follows for the subject of metaphysics that it comprises everything insofar as it has extramental being which is one with it and belongs to it essentially. Hence it follows that, just as the being which divides into the categories, being in the sense now under discussion is being that is independent and outside the mind [on kath' hauto exo tes dianoias].

l. The kind of being which is divided into actual [on energeia] and potential [on dynamei] is being in the sense in which this name is applied not only to that which is realized, that which exists, the really-being, but also to the mere real possibility of being.

Potential being [on dynamei] plays a large role in the philosophy of Aristotle, as does the concept of matter [hyle]. Indeed, these two concepts are coextensive,4 while actual being [on energeia] is either pure form or is actualized by form.

There is a great difference between what we here mean by the potential [the dynaton or dynamei on] and what in more recent times is meant by calling something possible in contrast with real, where the necessary is added as a third thing. This is a possibility which completely abstracts from the reality of that which is called possible, and merely claims that something could exist if its existence did not involve a contradiction. It does not exist in things but in the objective concepts and combinations of concepts of the thinking mind; it is a merely rational thing.

Aristotle was quite familiar with the concept of possibility so understood, as we can see from De interpretatione, but it bears no relation to what he calls potential being, since otherwise it would have to be excluded from the subject of metaphysics along with being as being true. So that no doubt may remain, he mentions in Met. [Metaphysics] V. 12, as well as in IX. 1, the impossible whose contrary is necessarily true [adynaton hou to enantion ex anankes alethes] (Met. V. 12. 1019b23). The possible object [dynaton] which is associated with this impossibility is distinguished from the potential object [dynaton] which bears this name because it stands in relation to a power [dynamis]. It is the same only in name5 and must be distinguished from this potentiality along with the powers of mathematics, a2, b3, etc., which are powers only in a metaphorical sense [kata metaphoran].6 Thus he speaks here of something which really has potential being. This is based upon his peculiar view that a non-real, something which has, properly speaking, non-being (me on)7, in a manner or speaking exists insofar as it is potentially, and it is this which leads him to a special wide sense of real being, which comprises as well that which potentially is.

Now, what is this potential thing which, being real, belongs to the object of metaphysics, and which has potential being as opposed to actual being? Aristotle defines it in the third chapter of the ninth book as follows: "a thing is possible if there is nothing impossible in its having the actuality of that of which it is said to have the potentiality."8 Two things are to be noted about this definition: (1) that Aristotle seems to define a thing through itself, since he defines the possible in terms of the impossible, and (2) the definition is based upon the concept of actuality whose understanding is therefore presupposed.

The first difficulty can be resolved as follows: the impossible [adynaton] in question is the contradictory. It is opposed to the possible in the logical sense which we have just discussed and not to the potential [dynaton] which we are now trying to comprehend.

The second difficulty forces us to direct our attention initially to actuality [energeia]. Potential being cannot be defined except with the aid of the concept of actuality, for the latter is prior in both concept and substance, as we are told in Met. IX. 8: "Actuality," he says, "is prior to potentiality both in concept and in essence." Further on he continues, "It is necessary that concept and cognition of the former precede that of the latter."9 "Actuality" [energeia, Wirklichkeit] derives from "to act" (ergo, wirken), a verb having to do with motion, since, as he says, it is especially motion which seems to be an actuality.10 But the extension of the concept does not stop here.11 What then is actuality? Aristotle does not give us a definition and declares explicitly that we should not demand one, since the concept of actuality is so basic and simple that it does not permit definition but can be clarified only inductively through examples.12 As one of these he adduces the knower, if we mean by this expression a person who is presently engaged in an act of cognition; hence, this person is actually cognizing. Furthermore, a statue of Hermes is actual if it is completely sculpted, finished, and not raw wood or a marble block to which the artist has not yet put his hand. If someone knows something but is not presently engaged in the act of cognition, or if a block is rough and unsculpted, then the former is not actually cognizing, even if he could perform the act of cognition, and the latter is not actually a statue, even if it is one potentially.13 Thus we see that we are led back to potential being; it is best to clarify the concept of actuality through the relation between actuality and potentiality. They are related "as that which is actually building to that which is capable of building, as that which is awake to that which is asleep, as that which is seeing to that which has eyes shut, but has the power of sight, and as that which is formed from matter is to matter, and as the finished article to the raw material. In this contrast let one member be assigned to actuality, the other to potentiality."14 We can see from this collection of examples that something is actual if it exists in complete reality; potential being lacks this reality, although "nothing impossible will result if potential being achieves the actuality of which it is said to be capable." (see above). Thus Aristotle often uses the designation "actuality" [energeia] and "entelechy" [entelecheia] interchangeably15 where the latter means the same as consummation (teleiotes),16 as was correctly noted by Alexander and Simplicus.17 But how? A mere potentiality in things, a merely potential thing which exists, is that not a thing which exists and yet does not have existence? Is this not a contradiction and impossibility? The Megarians did indeed see a contradiction here, as often happens if one withdraws the basis of being from contradictions which ought to be resolved. Thus they denied the merely potential, and that a thing is capable of something which is not already actual in the thing. But it is not difficult, says Aristotle,18 to reduce such an assertion to absurdity. For then there would not be a builder who is not presently engaged in building, and no one would have an enduring ability. But it is certain that a person who has exercised an art does not at once lose his knowledge and his capability, and that he does not have to learn and acquire them for every new use, and it is equally certain that the artist remains an artist, even if he rests from his activity. Furthermore, nothing would be cold or hot, and Protagoras would be correct in his claim that all truth depends upon subjective sensation and opinion.19 Furthermore, the man with healthy eyes and ears would often become blind and deaf during a day since, when he closes his eyes and ceases actually to see he would, on this theory, no longer see potentiality, i.e., he would have lost the very capacity to see.20 Finally, all coming to be and passing away of things would have become a complete impossibility, for everything would be what it can be, and what it cannot be it could never become, and whatever one might say of past and future things would be a lie.21

In this way, Aristotle rebuts the Megarians and clarifies for us the existence and justification of his potential being. The additional examples which he adduces in this context serve to remove all doubt about the meaning of "potential being." But perhaps it is possible to employ in addition a manner of illucidation which we have used above in the determination of accidental being [on kata symbebekos]. I have in mind the enumeration of the different kinds of potential being, or rather of the different ways in which various things participate in this name. This can be done since "potential being" is not used univocally, but applies to the concepts which fall under it merely with a certain unity of analogy. In Met. V. 12. four modes are indicated in which something can be called potential. They all agree in that they are origins of something,22 and all of them are reduced to a single principle from which they receive the name, and therein consists their analogy.23 The first mode of potentiality which Aristotle distinguishes is the origin of motion or change in another, insofar as it is another.24 The last clause is added on since the active principle could possibly be contained in the subject, as when something moves itself. Even then it is not moving and moved, active and passive, in one and the same respect; one and the same thing acts and receives action, but not insofar as it is the same, but insofar as it is another.25 The second mode is the passive capacity, which is the principle whereby something is moved by another insofar as it is another.26 Again, the last clause is added for similar reasons, since if something is passive with respect to itself, it is active not insofar as it is the same thing but insofar as it is another. The third mode of potentiality is impassivity [hexis apatheias], as he calls it in Met. IX. 1. 1046al 1. This is the disposition of a thing which makes it altogether incapable of suffering or change, or at least which makes it difficult for it to change for the worse. It is the so-called capacity of resisting.27 Finally, the fourth mode in which something is called a potentiality is the principle not just of doing or suffering something, but of doing it well and according to desire. Thus, for example, if somebody limps or stutters we do not describe him as one who can walk or talk; rather, we use these words for those who can do these things without stumbling and error. Similarly, green wood is called non-flammable, while dry wood is called flammable, etc.28

Corresponding to these four modes of potentiality, there are four kinds of things capable,29 which are most adequately described not as "possible" [moeglich] nor as "powerful" [maechtig], but rather as "capable" [vermoegend] or "able" [faehig]. All of these are called capable relative to a capacity [kata dynamin], which does not hold for the concept which logicians connect with the word "possible" [dynaton].30 As analogous concepts all of them can be reduced to the first mode of things capable and of potentiality, to the source of change in another insofar as it is another [arche metaboles en hetero he heteron], from which they also receive their name.31 It is a question whether the here-indicated modes of potentiality [dynamis] and of things capable [dynaton] will attain our purpose, which was to ascertain the various modes of potential being. Is it perhaps the case that our potential being [dynamei on] is one and the same as the thing capable [dynaton] which was just mentioned? We must deny this if we wish to retain the concept of potential being [dynamei on], which was introduced with sufficient clarity above. Both physics and metaphysics agree that the first principle of motion is to be sought in God, but God, though certainly a thing capable [dynaton], is in no way a potential being, since he is an actual being [on energeia] in the fullest sense of the word.32 Hence this kind of thing capable [dynaton], which occupies the third position in the above order, shows us that we should not seek the modes of potential being [dynamei on] in those of the things capable [dynaton]. But how? Is there only one mode of potential being [dynamei on] and is this the concept of a genus in which all things designated by that name participate in the same manner? What will be the method by which we gain knowledge of the various modes of potential being?

The third chapter of the ninth book speaks of a thing capable [dynaton]; the entire context and the examples themselves show clearly that in this case it is identical with potential being [dynamei on], and it is said that it is found in every category.33 The same holds, of course, also of actual being [on energeia]; thus the tenth chapter of the same book and the seventh chapter of the fifth claim that in every category some objects are said to be in actuality, others in potentiality.34 If this is so, then it is clear that potential as well as actual being is said in many ways and can be called one only by analogy. This is necessarily the case with everything that reaches beyond the extension of any one category, as Aristotle clearly indicates in Eth. Nic. [Nicomachean Ethics] 1.4. 1096al9 and other places. We, too, shall give a detailed demonstration of this point, and shall recognize the principles upon which it rests.35 Consequently, Aristotle also asserts explicitly of actual being that "not everything is said to have actual being in the same, but only in an analogous way: as one is in or to a second, so a third is in or to a fourth; for some are related as operation to potency, others as form to some sort of matter."36 And with respect to potential being [dynamei on] it is a major objection to Plato and the Platonists that they did not realize how every category presupposes as a different mode of being a certain determination and mode of potentiality.37 We have already touched upon the close relation between potential and actual and being which is divided into the categories,38 and we shall encounter a consequence of this fact, viz. the variegation of the concepts of potential as well as actual being. There are as many modes of potential being and actual being as there are categories; through the latter we shall understand the number of, and differences between, the former.

But something remains to be done for the complete determination of potential being [dynamei on]. The question is at what time is something potentially; the analogous question with respect to actual being does not occasion any doubts. It would certainly be incorrect to say of a newborn child that he is capable of speaking, of walking, or even of investigating the deepest principles of science. It is necessary that he should first grow in strength, that the germ of his talent should unfold so that he may acquire the ability, which he still lacks, to do all these things. Thus it is not correct to say that earth is a potential statue, for one cannot make such a statue of it until its nature has been changed, and it has become, for example, ore.39 But how, in general, can one determine when something is a potential being?

Anything which is potentially something else does not in reality become this thing except through the influence of an efficient cause. Thus to every potential being there corresponds a certain efficient cause and its activity, whether it be artificial, where the principle of realization is external to the potential being, or natural, where it resides within the latter. Anything has potential being if either nature or art can make it actual through a single action. It is potential through art if the artist can actualize it whenever he wants to, provided only that there is no external hindrance; thus, for example, something is called potentially healthy (curable) if it can become healthy through one application of medical art. Something is potential through nature if it can be lead to actuality by its peculiar active principle or its inherent natural power, provided only that no external hindrance stands in the way. In this manner, something is potentially healthy if there is nothing in the sick body which must be removed before nature can exercise her healing force. But wherever other changes are presupposed before the proper process of actualization can begin, there is no potential being. Trees which must first be felled and dressed, or the stuff which must first transform itself into a tree, these are not potentially a house; but when the beams from which it can be erected are finished, then one can say that the house has potential being. Thus the earth is not potentially a man, and even the semen is not, but if the foetus can become an actual man through its peculiar active principle, then it is already potentially a man.40

All this confirms anew the determinations given above of the concepts of actual being [on energeia] and potential being [on dynamei] so that there can be no further doubt about the sense which Aristotle connects with the word 'being' [on], insofar as he comprehends under it not only fully actualized, but also unactualized being, which is only potentially whatever it is, and strives toward and desires its form, as it were.41

2. Connections between states of potentiality and actuality. Movement [kinesis] as actuality which constitutes a thing as being in a state of potentiality.

In the previous section we have considered what Aristotle meant by actual being [on energeia] and potential being [on dynamis]. The latter appeared as being which was as such incomplete, and this is the reason why the perfect separate substance, God, does not in any way partake of potential being, but is pure actuality. On the other hand, if a thing is composed of substance and accident, matter and form, then this imperfection results in its not being free of potentiality; for such a thing actual being consists of a union of potential being with actuality.42 This is not inconsistent, as can be seen from the definition of potential being itself.

But aside from the what of potential and actual being we have also noted a when for both. For potential being we did so following Aristotle, while it is of itself clear that for actual being the state of its actualization through form must correspond to its completion. But while there is no doubt that this union of potential and actual being actually occurs, a union of the states which correspond to one or the other does not seem possible since the state corresponding to unactualized potential being is a state prior to actualization which, however, can be brought about through a single process of becoming.… Yet even their union is in a sense not inconsistent; of course, we do not here speak of a simultaneous union, for if a body is now potentially and later actually white, then this union in the subject is not properly called a union of states, and there are no problems with respect to this matter. A simultaneous union, however, is possible in this way: something which is actually ore is in a state of potentiality with respect to a certain figure, etc. This is a union no different from those occuring between something that has actual being with a second and a third thing which has actual being, as when one and the same subject is actually a body, actually large, actually green, etc. In this case, the actuality of that which actually is does not belong to the potential object as such; for example, the actuality of the ore belongs to the ore as ore but not as a potential statue.43 In the same manner we can explain the union of something actually alive with the potential corpse, etc. But there is a second manner in which both states can be united, and this occurs in the state of becoming, on kinesei, as Aristotle calls it.

In Met. XI. 9 he gives the following remarkable definition of motion [kinesis], which is not easily comprehensible in spite of everything he has already taught us about potentiality and actuality. He says this: "The actuality (energeia) of the potential (tou dynamei ontos) as such I call movement." Similarly, in the first chapter of Book III of the Physics: "Since being of every kind is divided into actual and potential being, the actuality (entelecheia) of potential being as such is motion." And farther down: "It is obvious that the actuality of what is potential as potential is movement."44

This definition makes it clear, first of all, that by potential being or the potential (dynamei on, dynaton), we are to understand that which is in a state of potentiality; for if we were to take it in the sense in which all matter as such, even after its union with form, is to be called something merely potential, then aside from the separate substances, every form would have to be called an actuality of a potential being, and nothing peculiar to movement would have been indicated.

But there is something else which causes problems: the words "the actuality of potential being" can be interpreted in two ways, as can be seen in the following: every form or actuality which is not a separate substance can be called an actuality of something in two ways: (1) as the actuality of the substratum, for example when we say of the soul that it is the actuality of the physical body which is potentially alive;45 and (2) as the actuality of the composite which was formed from matter through its union with form, for example when we say of the soul that it is the actuality of the living being. Since in our definition movement was described as the actuality of something, viz., of potential being, the question is whether this potential being is to be construed as subject or as something which is constituted through movement. Each interpretation, despite the difference, gives a true sense which agrees with what has been said so far, and which therefore ultimately coincides with the other. Let us show this by looking at both of them more closely. According to the first interpretation, which is adopted by most commentators,46 our definition would determine movement to be a form which has the following characteristics: as it brings its subject from the corresponding state of potentiality to [the] actuality [of movement], it leaves it in a state of potentiality to another thing. This other thing is such that the subject was in a state of potentiality to it by virtue of being in a state of potentiality to the actuality of the movement itself.

To understand this, we must remember what was said in the preceding section in answer to the question at what time something is a potential being. Something has potentiality if nature or art can make it an actuality through a single action, hence if it can be actualized through a single becoming. But this becoming, even if it must be single, does not have to be momentary. If a black body becomes white through a single change, it does not follow that it changes suddenly. Thus becoming and consummation do not coincide here; first the subject partakes in becoming, and then achieves its completion. Hence, here the subject has a double potentiality, viz. (1) to the becoming of the form, and (2) to the form itself. Yet this double state of potentiality is in itself and in its concept only a single one. For if a black body is capable of becoming white through a single becoming (hence as a potentiality to the becoming-of-the-form), it is obviously in a state of potentiality to whiteness. Now, if a subject is transferred from this state of potentiality to actuality with respect to becoming, then it is also transferred to a new and heightened state of potentiality with respect to the form which is the consummation of becoming.47 It is a heightened state insofar as the state of becoming is that from which the subject immediately achieves complete actuality, while the state before the state of becoming must first be changed into the state of becoming so that the subject may thereafter be transferred into a state of consummate actuality. Hence commentators have described this state as a third, intervening, state between mere potentiality and actuality;48 this state of an actual tendency after the act is being qua movement [on kinesei], while movement [kinesis] is that becoming which actualizes but does not completely exhaust potentiality.

Thus there are no further difficulties in understanding the definition. The kind of thing something is [he toiouton esti] distinguishes this kind of union between states of potentiality and actuality from the one mentioned above in which, for example, the actuality of the ore as ore coexisted with the potentiality of being a statue.49

The authority of almost all commentators speaks for this interpretation; yet, as mentioned above, there is still another possible interpretation which has its own advantages. The first interpretation made good sense with respect to movement [kinesis], yet it does not seem free of inaccuracies. For if the double potentiality of the subject were really only one, both in itself and according to the concept (haplos kai kata ton logon, Physics III. 1. 201a32), then it would be impossible for this state to be terminated with respect to one of them, and to continue with respect to the other. For if it is terminated with respect to whatever, then it is completely terminated, hence for both. And if only the becoming of the form has become actual, while the form itself is still potentiality, it has not remained in the previous, but in a new and more advanced state of potentiality, viz. precisely its state of becoming. Thus in a sense a subject has remained in a state of potentiality, just as I can say of something which is now white and then red that it has remained in a state of actuality with respect to color, although it is now colored by virtue of a different state of actuality than before; but in the strict sense the subject has not remained in a state of potentiality; rather, it has been transferred from one state of potentiality to a second state which aims at the same form, i.e., it is in a state of becoming, which is constituted by movement.

Thus, if the great authority of the men who maintained the first interpretation did not make me hesitate, I would unquestionably prefer the second, according to which the definition determines as follows: Movement is the actuality of the potential as such, just as the form of the ore is the actuality of the ore as such, i.e., it is the actuality (energeia) which makes something that is potentially (tou dynamei ontos) into that which it is (he toiouton esti), viz. into this potential being. In other words, it constitutes and forms a potential (it constitutes and forms something which is in a state of potentiality as being in this state). After what has been said, the definition when put this way has no further difficulties. This interpretation has the advantage that it makes the definition not only more precise, but also simpler. Let the following contribute to its comprehensibility, where we make constant reference to the appropriate passages in Aristotle to show that our argumentation agrees with his meaning. We shall show (1) that there are potentialities which are constituted as such through some actuality, (2) that this is not the case with all potential states, and (3) that where it is the case, the constituting actuality is a movement.

The first point is likely to provoke the most doubt and opposition, hence we want to treat it with special care. Thus we shall conduct our proof as follows: we shall show (1) that in many cases there are two different states of potentiality which are related to the same state of actuality; and (2) that, where there is such a multiplicity of potential states, at least one of them must be constituted (or formed) by some actuality. We begin by referring back to the previous section, in which we saw that aside from that which is in a state of actuality [the energeia on], there is also being in the state of potentiality [on dynamei].50 But in virtue of what is something constituted an actual being [on energeia]? Obviously, through a form or actuality. But what about a potential being? Is it, too, constituted (formed) as such by something? It is indeed difficult to believe that a state of potentiality as such can be constituted through a form, which is, after all, an actuality;51; yet this is the case, provided only that there is a double state of potentiality with respect to the same form, as we have just said.…

Let us again consider and confirm this fact. We have said that there is often a double state of potentiality with respect to the same actuality, and this was derived from another truth which was proved earlier (p. 37), viz. that there are double states of potentiality, i.e., that there are things which, by virtue of one and the same state (one and the same in itself and in concept (haplos kai kata ton logon), have potentiality to two different actualities. For example, something which is potentially white has potentiality for whiteness and also for becoming-white by virtue of one and the same state, since a single operation, namely white-making, actualizes both (see above). From this we have concluded that if both actualities could occur only one after the other, the first of them would have to terminate the state of potentiality with respect to the second, for the two states of potentiality are one and the same. But since the subject maintained the potentiality to the second form, it could do so only by virtue of a second, new state of potentiality to this form.… It follows from this that there are two states of potentiality corresponding to this actuality. Hence there is a double state of potentiality with respect to the same actuality.

We can support this argument by a second one. If there is a state of potentiality with respect to a form from which and by virtue of which the subject can immediately attain possession of actuality, and if there is a state of potentiality with respect to the same form, from which and by virtue of which the subject cannot immediately attain possession of actuality, then these two states are distinct and there is a double state of potentiality with respect to one and the same form. But the antecedent of this conditional proposition is true, hence also the consequent. For it is true that a stone which is thrown is capable (has potentiality) of reaching a certain location toward which it has been thrown, and that from the state in which it is now, viz. the state of a-thing-being-thrown, it immediately attains a state of rest having reached its target. And it is true that a stone which rests in a certain location is capable of attaining another location since it can get there through a single throw, and yet it cannot immediately get there from the state in which it is before the throw; it must first attain the state of being-thrown. Here we have an example of two states of potentiality with respect to the same actuality. We take this argument from Aristotle himself when he says, in the second book of the Metaphysics, that there is a double way in which something comes from something, as a man from a boy who matured to manhood, or the air from water; in the first case, that which is becoming changes into that which has become, out of that which is in the process of completion (actualization) there arises the completed (the actual). "For," he says, "there is always an intermediate: just as becoming is between being and non-being, so that which is becoming is between what is and what is not."52

We take a further confirmation of our claim from the same passage: that we have here two different states follows from the fact that there is a characteristic which is peculiar to one of them, but which the other lacks. Something can pass from a state of becoming into a state of actuality, but not vice versa; for what is already white cannot become white. But from the state of potentiality prior to becoming, a thing attains the state of actuality, and conversely; for the black is potentially white, and after it has actually become white, it is potentially black and can therefore return to this state.53

But wherever such a multiplicity of potential states is found, at least one must as such be constituted (formed) through an actuality. This is perfectly clear and certain. For privation as such does not constitute anything. It is itself only accidental being [on kata symbebekos] and, taken by itself, has no existence at all;54 while matter, as such, is undifferentiated, and since it receives all its determinations from the form through which it is what it is, there can be only one matter with respect to one and the same form.55 Hence, how could this matter produce the difference between the state of becoming and the state of the potentiality to the same form prior to becoming? Impossible! Rather, only one thing is possible, viz. that the difference between the two states of potentiality is produced by a form, so that at least one of the two states as such is constituted (formed) through an actuality. And this is what we had wanted to prove in the first place, and what at first sight is liable to occasion considerable doubt, i.e., that there are states of potentiality which are constituted as such through an actuality.

One can also show this in another way once the above established proposition has been secured, i.e., that one and the same state of potentiality (one and the same both in itself and in concept, see above p. 37) is a state of potentiality with respect to two actualities. For if the two actualities considered by themselves are two, then they must be one in their relation [in der Ordnung] to this state of potentiality, and so one of them must be a function of the other [zur andern hingeordnet sein], hence must give the subject an actual tendency toward itself, i.e., toward a new state of potentiality which is closer to it, an intermediate state between the first and actuality.56

Now we come to the second point. If the preceding investigation has made it clear that many things which are in a state of potentiality are constituted as such through a form, this is not to say that this must be the case with everything that is in a state of potentiality. On the contrary, this, too, would be an error; consequently, we find Aristotle opposing it in the third book of the Physics and the corresponding part of the eleventh book of the Metaphysics. Let us now give a somewhat more complete version of his argumentation. If something is in a state of potentiality, and is constituted as such by an actuality, then (1) it must be in a state of actuality, and (2) it must, as such, have a form, and therefore an essence and a concept which determines this form, for each form issues in an essence. From this it follows, for instance, that a motionless waxen ball, which is potentially a cube, is not constituted by an actuality as being in that particular state [of potentiality]. For, of all the forms which are in a wax ball, it can only be the actuality of the wax as wax, or the softness of the wax, which lend it a certain disposition that facilitates reshaping it. But when the wax ball has become a cube, the form of the wax as wax, hence also its softness, hence everything through which the wax was formerly constituted remains; now, if this were a state of potentiality, hence a state prior to actuality, then the cube which has come about would not yet be a cube, which is contradictory. Hence, one would have to believe that it is the form of the wax ball as a sphere which constitutes the potentiality of becoming a cube; for it is indeed true that whatever has the shape of a sphere cannot at the same time be a cube. But against this a second argument can be advanced which is also decisive with respect to the previously mentioned form of the wax. The wax ball is a potentiality not only to the form of the cube but to a thousand other shapes as well. Hence, all these states of potentiality would have to be constituted through the form of the ball (or the wax) if the wax ball as sphere (or as wax) were indeed presently in a state of potentiality, and hence they would have to be identical with the sphere (with the wax) as such (i.e., in themselves and in this essence and concept). But this is impossible; for if two are identical with the same third thing, then they are identical with each other, and hence the innumerable different states of potentiality to become a cube, a tetrahedron, a dodecahedron, a icosahedron and other regular and irregular forms would have to be both in themselves and in concept [haplos kai kata ton logon] identical, although they are as different as these forms themselves which diverge from each other in a number of directions. Hence, it has been established that the wax ball by being constituted as wax through the actuality of the wax, and as a sphere through the spherical figure, is not constituted through any of its actualities as having a state of potentiality to become a cube. Hence it has a potentiality to be in this state without being constituted in this respect by any of its actualities.57

We come to the third point. Having seen that there are two kinds of states of potentiality, one of which is constituted as such by an actuality while the other is not, the question now is which states of potentiality are constituted by an actuality or, what comes to the same, which actualities constitute potential states as such.

All potential being as such stands in a relation to an active principle; for the subject is potentially something if it can become an actuality through a single act of an active principle. Thus we must also examine those states of potentiality which are constituted as such through an actuality in their relation to an active principle and its operation. Thus a state of potentiality to become something exists in a subject either before the operation, or during the operation, or after the operation of the force through whose activity it is transformed into a state of actuality. But it can obviously not exist after the activity, for if the activity has passed nothing remains that can be realized through this activity; what this activity was capable of actualizing either exists now or has existed in actuality. With respect to this activity at least it does certainly not exist in potentiality, whether or not the latter be constituted through a form. Hence, it remains to consider the states of the subject prior to and during the activity. But the state of potentiality which exists in the subject prior to the activity cannot be constituted through an actuality. For at that point there are only three forms in the subject which must be considered. One is to be envisaged as the terminus a quo for the change, as for example the spherical figure of the wax which is to be transformed into a cube. A second, which is the most deceptive and is therefore the only one considered by Aristotle, is the form which constitutes the subject as that which it actually is. In the case of the wax ball, this is the actuality which constitutes the wax as wax. Finally, there is a third form, in the case of the wax it is softness, which lends a certain disposition to the subject.58 But in considering the second point we have already shown that none of these forms constitutes a potential being as such. Hence the latter, as such, does not possess any actuality. On the other hand, the state of potentiality in which the subject is during the activity of the active principle is indeed a state which is constituted, as such, through an actuality. For the principle acts only to the extent in which the subject receives an influence, i.e., something actual. Now, if the subject is still in a state of potentiality with respect to this force and its activity, then this is due to a further state of potentiality: we have shown this above when we discussed the first point, and everything else said there applies here as well.

The only remaining question is what we should call those states of potentiality which exist during the activity of the acting principle and what to call those actualities which potentialize the subject, as it were. We commonly call them states of becoming or movement,59 and as movement they must be considered actualities which constitute a potential thing as potential. Induction shows this. While the builder builds, that with which he builds is in a state of potentiality which is constituted by actuality, but the building material as such was only a potentiality with respect to house construction and to the edifice. Either the actuality of constructing or the actuality of the edifice must therefore be that which constitutes that higher state of potentiality. But not that of the edifice, for the edifice as such is no longer a potentiality with respect to the builder and this building activity of his; hence, the actuality in question must be the building activity (oikodomesis), and this is indeed a movement (kinesis). One can give a similar demonstration with respect to all other movements.60 If that which is potentially a building is constituted as such through an actuality, then it is presently in the process of being erected, and just this is house construction, hence movement. The same occurs when something heals, when there is a revolution, a jump, etc.61 Hence, movement is the actuality of that which is in a state of potentiality as such, the actuality of the potential as potential. For example, the movement toward a quality (alloiosis) constitutes that which is becoming a quale (poion) in this state of potentiality toward a quality; similarly, the movement toward quantity (auxesis kai phthisis) constitutes that which is about to become a quantum (poson) in this state of potentiality toward a quantity; furthermore, locomotion (phora) constitutes that which moves toward a goal in this state of potentiality for a location. Now, if there is such an intermediate state of potentiality also in the domain of the substantial, then the state of substantial becoming and passing away through generation and corruption (genesis kai phthora) must be formally constituted in the same way, and these, too, will be movements.62

Aristotle, after he has advanced and positively supported his view of movement, seeks to support it further by a polemic against definitions of earlier philosophers, which seems to be aimed especially at Plato;63 he does so in the Physics III.2. and the corresponding part of the eleventh book of the Metaphysics. Here as elsewhere his polemic is never unfruitful, since it always manages to find and isolate what is correct in a mistaken position. He notes that earlier attempts had defined movement as otherness, as inequality, and as non-being. None of these definitions describe the essence of movement, for none of these need to be moved, neither that which is other, nor that which is unequal, nor that which has non-being. It is peculiar to the state of becoming that that which is in the state of becoming has a potentiality to acquire the state of that which has become, while that which has become does not have a state of potentiality to acquire that particular state of becoming from which it arose, as we have seen above,64 while, on the other hand, the equal passes into the unequal, as well as the unequal into the equal, and being into non-being, as well as non-being into being, etc.65 But what occasioned these mistaken definitions? There is indeed something in the nature of movement which could lead one to put it into the order66 of privation. Since becoming does not form a special species of things, but must be reduced to the species of accomplished being,67 as that which is growing large to largeness, and that which is in the process of acquiring a certain characteristic to that characteristic, one is inclined to take it for something indeterminate, something lacking form. What else is one to make of movement? The potentiality (dynamis) by virtue of which something is potentially is not movement, and what is actually [energeia] something is also not in motion; thus the only thing left seems to declare motion to be an unfinished actuality [energeia], an accomplished reality [entelecheia] for which there is no completion, which, unless we envisage it as a privation, seems to be a contradiction. But the puzzle is resolved in this way: as actualization [energeia], movement constitutes something as being in a state of potentiality as such, and the potential is of course incomplete;68 hence, that which completes [vollendet] is indeed a state of incompleteness;69 it actualizes a state which is prior to actuality. "Therefore," says Aristotle, "it is difficult to grasp what movement is, for one either thinks that it either has to be defined as a privation or as a potentiality, or simply as an actuality; yet none of these seem possible. Hence the indicated way is the only one that remains, namely that it is an actuality, but the kind we have described, which is difficult to grasp, but nonetheless possible."70

Thus it becomes clear how, under this interpretation of the definition, everything Aristotle teaches about movement agrees. For what we have just touched upon, viz. that movement does not form a special species of being, but follows the various species as does actuality as such, and potentiality as well, is also fully consonant with this. Movement as actuality constitutes a state of potentiality. Since the states of potentiality belong to the same genus as the corresponding states of actuality, just as the possible body belongs, with the actual body, to the genus of substance, and the potentially white belongs, with the actually white, to the genus of color and of quality, etc., in the same way the thing-in-motion [on kinesei] and motion [kinesis] must be reduced to the particular species of that which comes about through this motion, and must belong to the same genera as the complete being. This is not to say that there is a motion [kinesis] in every species of being, as there is a potentiality [dynamis] and an actuality [energeia]. A state of becoming, i.e., a second state of potentiality which is to be formed by the proper movement, can occur only where there is gradual, continuous becoming, and this can be found only where there are contrary concepts, and hence intermediate states, which are absent where there is an opposition of contradictories. The transformation from non-being to being can only be sudden and momentary. After having declared in Physics III. I and Met. XI. 971 that "there are as many kinds of movement and change as there are kinds of being," Aristotle delineates these matters at some length in the third book of the Physics (and the corresponding part of the eleventh book of the Metaphysics72) and makes the qualification that proper movement is to be restricted to the three categories of quality, quantity and location, where alone the requisite conditions are satisfied, as he shows by a careful investigation.73

Still and all, we do not actually wish to contest the first interpretation; despite the considerable formal difference of the two interpretations they do not, in the end, differ essentially, as we have already pointed out. We note that according to both of them the thing in motion [on kinesei] exemplifies a peculiar mode of union of a potential and an actual state. The second interpretation allows this union to be very clearly indicated in the definition of motion, by saying that motion is an actuality which, by producing its actual state, constitutes a state of potentiality, i.e., constitutes the potential as potential. We see that here, too, the subject which is in the state of becoming occupies an intermediate state between a more distant potentiality and actuality; but by being in this one state, it has simultaneously a state of actuality with respect to becoming, movement; it has potentiality with respect to the form which is approached through movement.

This middle state is also attained by potentialities which have the peculiar characteristic that there cannot be a complete reality corresponding to the potentiality. Just as the concept of movement has something in it which is difficult to grasp, and which at first occasions astonishment and doubts concerning the correctness of the definition (cf. Met. 1. 2; 983al4), many will find it difficult to admit, initially, that there can be a potentiality to which no actuality corresponds, at least not one which exists in rebus though perhaps one which is thought and comprised within its concept since, they will say, something is called potential only in relation to an actuality. Yet such is the case, as the example of any line and of any solid clearly shows. The line, which in actuality is one, can be halved, and thus is potentially two, and since the half is capable of further division, it is potentially four; hence, it is potentially two, four, eight, sixteen, etc. But what is the limit of this potentiality? It does not have a limit; while it is in actuality one, it is potentially infinitely many. But this potentiality is never exhausted by an actuality. The infinitely many lines which are now contained as parts in one line will never actually exist as infinitely many actual lines. Here, and wherever else we are concerned with bodies,74 the infinite exists always only in a state of potentiality, either as a state of potentiality prior to movement (one line has infinitely many parts), or as thing in motion (on kinesei), when a division into infinity is attempted. Similar considerations hold for surfaces, bodies, and other things.75

So much for being insofar as it comprises real potentiality, becoming, and that which is in a state of complete being, being in the sense of potential and actual being [on dynamei kai energeia].


1 Cf. Brandis, op. cit., III, 1, 46, n. 85 and the passage from Prantl quoted there.

2 Books VII and VIII deal with the being [on] of the categories and of substance [ousia] respectively, Book IX of potential and actual being [dynamei kai energeia on].

3 See above p. 1.

4 Cf. Zeller, Philosophie der Griechen, II, 2, p. 238, n. 5. Matter [hyle] must of course be taken in a wider sense in which it includes, in addition to primary matter [prote hyle], also the subjects of the accidents. Then Zeller's remark is correct that "a thing is potentially [dynamei] only insofar as it has matter [hyle] within itself." Met. XIV. 1. 1088bl: "The matter of each thing must be that which is potentially of the nature in question."

5Met. V. 12. 1019b21: "Some things, then, are called adynata [not potent] in virtue of this kind of incapacity, while others are so in another sense; i.e., both dynaton and adynaton are used as follows, etc." As belonging to this merely rational possibility [dynaton] he enumerates: "The possible, then, in one sense, means that which is not of necessity false; in one that which is true; in one, that which may be true." Cf. Met. IX. 1. 1046a8.

6Met. V. 12. 1019b33: "A 'potency' or 'power' in geometry is so-called by a change of meaning." Cf. Met. IX. 1. 1046a7: "Some are called so by analogy." The similarity consists in this: that just as potential being turns into actual being, so from the multiplication of the root with itself is generated the magnitude whose root it is.

7Met. XIV. 2. 1089a28.

8Met. IX. 3. 1047a24: "And a thing is capable of doing something if there will be nothing impossible in its having the actuality of that of which it is said to have the capacity. I mean, for instance, if a thing is capable of sitting and it is open to it to sit, there will be nothing impossible in its actually sitting; and similarly if it is capable of being moved or moving, or of standing or of making to stand, or of being or coming to be, or of not-being or not coming to be."

9Met. IX. 8. 1049blO: "To all such potency, then, actuality is prior both in formula and in substantiality … so that the formula and the knowledge of the one must precede the knowledge of the other."

10Met. IX. 3. 1047a30: "The word 'actuality', which we connect with 'complete reality', has, in the main, been extended from movements to other things; for actuality in the strict sense is thought to be identical with movement."

11Ibid., 6. 1048a25.

12Ibid., a35: "Our meaning can be seen in the particular cases by induction, and we must not seek a definition of everything."

13Ibid., a30: "Actuality, then, is the existence of a thing not in the way which we express by 'potentially'; we say that potentially, for instance, a statue of Hermes is in the block of wood and the half-line is in the whole, because it might be separated out, and we call even the man who is not studying a man of science, if he is capable of studying; the thing that stands in contrast to each of these exists actually."

14Met. IX. 6. 1048a36: "And we must not seek a definition of everything but be content to grasp the analogy, that it is as that which is building is to that which is capable of building, and the waking to the sleeping, and that which is seeing to that which has its eyes shut but has sight, and that which has been shaped out of the matter to the matter, and that which has been wrought up to the unwrought. Let actuality be defined by one member of this antithesis, and the potential by the other." Cf. Schwegler concerning the reading of this passage.

15 Cf. Schwegler, Metaphysik des Aristoteles, 4, 222.

16 Ancient as well as recent commentators are in disagreement concerning the distinction between "energeia" and "entelecheia", but the difference between their opinions is much larger than the difference between the concepts that are designated by these two names. They are indeed applied to different things. It is not so much the case that they differ from one another, but that each differs from itself in different uses [contexts]; for "actual being" [on energeia] is not a univocally, but an analogously used name, as we shall see when the categories are discussed. Thus it could happen that commentators came to opposing views depending on the passage upon which they focussed. Many attribute more consummate reality to entelecheia than to energeia, while Schwegler claims (op. cit.) "energeia is the activity (self-employment) in consummate being, while entelecheia is striving activity connected with dynamis." On energeia as well as on entelecheia mean that which is realized and completed through form. But while the designation "entelecheia" expresses this through the very word, the name "energeia" is taken from movements (as Aristotle teaches, cf. above, n. 10) not because that which is in motion is energeia in the fullest sense, but of all realities movement strikes our eye first. Movement is not asserted of anything that is not real, while other predicates, such as thinkable and desirable, also apply to non-being (Arist., ibid).

17 In connection with Physics 358al9 ff.

18Met. IX. 3. 1046b29: "There are some who say, as the Megaric school does, that a thing 'can' act only when it is acting and when it is not acting it 'cannot' act, e.g., that he who is not building cannot build, but only he who is building, when he is building; and so in all other cases. It is not hard to see the absurdities that attend this view. For it is clear that on this view a man will not be a builder unless he is building (for to be a builder is to be able to build)."

19Met. IX. 3. 1047a4.

20Ibid., a7.

21Ibid., a10.

22Met. IX. 1. 1046a9: "All are originative sources of some kind."

23 See below chap. 5, sect. 3.

24Met. V. 12. 1019al5: "'potency' means a source of movement or change, which is in another thing than the thing moved or in the same thing qua other, etc."

25 Cf. below chap. 5, sect. 13.

26Met. V. 12. 1019a20. "'Potency' then means the source of change or movement by another thing or by itself qua other."

27Ibid., a26: "The states in virtue of which things are absolutely impassive or unchangeable, or not easily changed for the worse, are called potencies; for things are broken and crushed and bent and in general destroyed, not by having a potency but by not having one and by lacking something, and things are impassive with respect to such processes if they are scarcely and slightly affected by them because of a 'potency' and because they 'can' do something and are in some positive state."

28Met. V. 12. 1019a23: "The capacity of performing this well or according to intention … so too, in the case of passivity." This kind of potentiality [dynamis] is here actually mentioned in the third place. According to the order which is used in IX. 1, which we have followed, and which corresponds to the order of things capable [dynata], we have introduced it as the fourth.

29Ibid., a32 ff.

30 See above, n. 5.

31Ibid., b35: "But the senses which involve a reference to potency all refer to the primary kind of potency; and this is a source of change in another thing or in the same thing qua other. For other things are called 'capable', because something else has such a potency over them, some because it has not, some because it has it in a particular way, etc."

32 In order for something to be a potential being [dynamei on] it does not suffice that the principle of an activity should be found in it; doing [poiein] must also belong to it as a proper accident (see below, chap. 5, sect. 13). This is not the case with God.

33Met. IX. 3. 1047a20: "So that it is possible that a thing may be capable of being and not be, and capable of not-being and yet be, and similarly with the other kinds of predicates; it may be capable of walking and yet not walk or capable of not walking and yet walk."

34Met. IX. 10. 1051a34: "The terms 'being' and 'non-being' are employed firstly with reference to the categories, and secondly with reference to the potency or actuality of these or their non-potency or non-actuality." V. 7. 1017a35: "Again, 'being' and 'that which is' mean that some of the things we have mentioned 'are' potentially, others in complete reality." (At this point he has already discussed the categories.) Cf. also De anima II. 1. 412a6.

35 See below chap. 5, sect. 3.

36Met. IX. 6. 1048b6: "But all things are not said in the same sense to exist actually, but only by analogy—as A is in B or to B, C is in D or to D; (for this reading cf. Bonitz, Observationes criticae in Aristotelis libros Metaphysicae [Berlin, 1842]). Some are as movement to potency, and the others as substance to some sort of matter." Cf. below, chap. 5, sect. 13.

37Met. XIV. 2. 1089a34: "Now it is strange to enquire how being in the sense of 'what' is many, and not how either qualities or quantities are many." b15: "What is the reason, then, why there is a plurality of these? It is necessary, then, as we say, to presuppose for each thing that which it is potentially." See Met. X. 3. 1054b28.

38 Cf. the beginning of this chapter.

39Met. IX. 7. 1049a17: "Just as earth is not yet potentially a statue (for it must first change in order to become brass)."

40Met. IX. 7. 1049a3: "Just as not everything can be healed by the medical art or by luck, but there is a certain kind of thing which is capable of it, and only this is potentially healthy. And (1) the delimiting mark of that which as a result of thought comes to exist in complete reality from having existed potentially is that if the agent has willed it it comes to pass if nothing external hinders, while the condition on the other side—viz. in that which is healed—is that nothing in it hinders the result. It is on similar terms that we have what is potentially a house; if nothing in the thing acted on—i.e., in the matter—prevents it from becoming a house, and if there is nothing which must be added or taken away or changed, this is potentially a house; and the same is true of all other things the source of whose becoming is external. And (2) in the cases in which the source of the becoming is in the very thing which comes to be, a thing is potentially all those things which it will be of itself if nothing external hinders it. E.g., the seed is not yet potentially a man; for it must be deposited in something other than itself and undergo a change. But when through its own motive principle it has already got such and such attributes, in this state it is already potentially a man; while in the former state it needs another motive principle, just as earth is not yet potentially a statue (for it must first change in order for it to become brass)."

41 Cf. Physics I. 9. 192b 16.

42 E.g., De anima, II. 1. 412a6: "We are in the habit of recognizing, as one determinate kind of what is, substance, and that in several senses, (a) in the sense of matter or that which in itself is not 'a this', and (b) in the sense of form or essence which is that precisely in virtue of which a thing is called 'a this', and thirdly (c) in the sense of that which is compounded of both (a) and (b). Now matter is potentiality, form, actuality."

43 Cf. Physics III. 1. 201a29. Ibid., 21.

44Met. XI. 9. 1065bl6: "I call the actuality of the potential as such, movement." Physics III. 1. 201a9: "We have now before us the distinctions in the various classes of being between what is fully real and what is potential. The fulfillment of what exists potentially, insofar as it exists potentially, is motion." Ibid. b4: "Clearly it is the fulfillment of what is potential as potential that is motion."

45De anima, II. 1. 412al9: "Hence this soul must be a substance in the sense of the form of a natural body having life potentially within it. But substance is actuality, and thus soul is the actuality of a body as above characterized."

46 E.g., Simplicius, In Aristotelis Physicorum commentarium, ed. Hermann Diels, Com. in Arist. Gr., IX (Berlin 1882), 414: "Whenever a thing changes from potentiality to actuality, with the potentiality remaining in the thing, we say it moves." Similarly Themistius and otheo.

47 Philiponus, In Aristotelis Physicorum libros tres priores commentaria, ed. Hieronymus Vitelli, Com. in Arist. Gr. 16 (Berlin 1887), 351: "They explain motion (Themistius changed this somewhat) as the first entelechy of potential being as such; for the final entelechy is the transition to the form in which it remains thereafter; by contrast, the first entelechy is the passage toward the form; and this is motion."

48Simplicius, loc. cit.: "Therefore, insofar as something is in actuality, it moves not at all. Also insofar as something potential remains potential and merely capacity, we would not say that it moves. But when it changes from potentiality to actuality, and the potentiality remains in it, then we say it moves."

49Physics III. 1. 201a29. Also Met. XI. 9.

50Physics III. 1. 201a9: "The distinctions in the various classes of being between what is fully real and what is potential…" Similarly Met. XI. 9.

51De anima, II. 1. 412a8: "Now matter is potentiality, form actuality." Met. VIII. 2. 1043a27: "One kind of it [is substance] as matter, another as form or actuality."

52Met. II. 2. 994a22: "For one thing comes from another in two ways—not in the sense in which 'from' means 'after' (as we say 'from the Isthmian games come the Olympian'), but either (1) as the man comes from the boy, by the boy's changing or (2) as air comes from water. By 'as the man comes from the boy' we mean 'as that which has come to be from that which is coming to be. Or as that which is finished from that which is being achieved' (for as becoming is between being and not being, so that which is becoming is always between that which is and that which is not; for the learner is a man of science in the making, and this is what is meant when we say that from a learner a man of science is being made); on the other hand, coming from another thing as water comes from air implies the destruction of the other thing."

53Met. II. 2. 994a31: "This is why changes of the former kind are not reversible, and the boy does not come from the man (for it is not that which comes to be something that comes to be as a result of coming to be, but that which exists after the coming to be; for it is thus that the day, too, comes from the morning—in the sense that it comes after the morning; which is the reason why the morning cannot come from the day); but changes of the other kind are reversible."

54 See above, pp. 8f.

55Met. VIII. 2. 1043al2: "The actuality or the formula is different when the matter is different."

56Met. II. 2. See above, n. 52.

57Physics III. 1. 201a31: "For 'to be bronze' and 'to be a certain potentiality [for motion]' are not the same.… (This is obvious in contraries. 'To be capable of health' and 'to be capable of illness' are not the same, for if they were there would be no difference between being ill and being well. Yet the subject both of health and of sickness—whether it is humor or blood—is one and the same.) We can distinguish, then, between the two just as, to give another example, 'color' and 'visible' are different, and clearly it is the fulfillment of what is potential as potential that is motion."

58Physics III. 1. Cf. the preceding note.

59Physics III. 1. 201a27: "[the fulfillment of] a potential thing, as thing moved, is motion, whenever this fully real being is in the process of bringing about (either itself or another)." [Brentano relies on a different reading than Ross for this difficult passage. We translate the Brentano version. The quotation continues:] "what I mean by 'as' is this: bronze is potentially a statue. But it is not the fulfillment of bronze as bronze which is motion. For 'to be bronze' and 'to be a certain potentiality' are not the same."

60Physics III. 1. 201b5: "further it is evident that motion is an attribute of a thing just when it is fully real in this way, and neither before nor after. For each thing of this kind is capable of being at one time actual, at another not. Take for instance the buildable as buildable. The actuality of the buildable as buildable is the process of building. For the actuality of the buildable must be either this or the house. But when there is a house, the buildable is no longer buildable. On the other hand it is the buildable which is being built. The process then of being built must be the kind of actuality required. But building is a kind of motion, and the same account will apply to the other kinds also."

61Ibid., a15: "Examples will illucidate this definition of motion. When the buildable, insofar as it is just that, is fully real, it is being built, and this is building. Similarly, learning, doctoring, rolling, leaping, ripening, aging."

62Physics III. 1. 201b4: "Clearly it is the fulfillment of what is potential as potential that is motion." Ibid. al0: "The fulfillment of what exists potentially, insofar as it exists potentially, is motion—namely, of what is alterable qua alterable, alteration: of what can be increased and its opposite what can be decreased (there is no common name), increase and decrease: of what can come to be and can pass away, coming to be and passing away: of what can be carried along, locomotion."

63 Cf. Alexander Aphrodisiensis, In Aristotelis Metaphysica Commentaria, Com. in Arist. Gr., I (Berlin 1891), 396.

64Met. II. 2; See above, n. 53.

65Physics III. 2. 201bl9: "This is plain if we consider where some people put it; they identify motion with 'difference' or 'inequality' or 'not being'; but such things are not necessarily moved, whether they are 'different' or 'unequal' or 'non-existent'; nor is change either to or from these, rather to or from their opposites."

66 According to the order of the Pythagoreans; cf. C. A. Brandis, ed. Scholia in Aristotelem (Berlin 1836), pp. 360a8 and 360al5.

67Physics III. 2. 201b24: "The reason why I put motion into these genera is that it is thought to be something indefinite, and the principles in the second column are indefinite because they are privative: none of them is either 'this' or 'such' or comes under any of the other modes of predication." Ibid., 1. 200b32: "There is no such thing as motion over and above the things. It is always with respect to substance or to quantity or to quality or to place that what changes changes. But it is impossible, as we assert, to find anything common to these which is neither 'this' nor quantum nor quale nor any of the other predicates. Hence neither will motion and change have reference to something over and above the things mentioned, for there is nothing over and above them."

68Physics III. 2. 201b27: "The reason in turn why motion is thought to be indefinite is that it cannot be classed simply as a potentiality or as an actuality—a thing that is merely capable of having a certain size is not undergoing change, nor yet a thing that is actually of a certain size, and motion is thought to be a source of actuality, but incomplete, the reason for this view being that the potential whose actuality it is is incomplete." De anima III. 7. 431a6: "Movement, is as we saw, an activity of what is imperfect."

69 In following the first interpretation one encounters the difficulty (cf. Brandis, op. cit., p. 358al9) that Aristotle describes movement [kinesis] not only as actuality [energeia] but also as consummate reality [entelecheia] which implies a consummation [teleiotes, see above sect. 1]. It is easy for us to explain this. Just as motion [kinesis] constitutes a state of becoming, and realizes this state, for which reason it is actuality [energeia], so it also consummates it as such and is therefore called a consummate reality [entelecheia]. It thus produces a more advanced, higher, and as it were, more consummate state of potentiality.

70Physics III. 2. 201b33: "This is why it is hard to grasp what motion is. It is necessary to class it with privation or with potentiality or with sheer actuality, yet none of this seems possible. There remains then the suggested mode of definition, namely, that it is a sort of actuality, or actuality of the kind described, hard to grasp, but not incapable of existing."

71Physics III. 1. 201a8: "Hence there are as many types of motion or change as there are meanings of the word 'is'." See also Met. XI. 9.

72 Cf. Met. XI. 11. 1067b14ff. Likewise Physics III.

73Met. XI. 12. 1068a8: "If the categories are classified as substance, quality, place, acting or being acted on, relation, quantity, there must be three kinds of movement—of quality, of quantity, of place." Similarly Physics III. For those things which do not allow an intermediate state between the state prior to becoming and actuality and for which consequently there is not motion [kinesis], (hence, as we are told, for all categories outside of quality, quantity, and place [poion, poson, and pou]) the state of potentiality prior to becoming, which is not constituted by any form as such, is to be described as a state of most proximate potentiality. The state of their becoming is the state of actuality at the first moment.

74 Cf. Physics III. 5. 204a8.

75Met. IX. 6. 1048b9: "But also the infinite and the void and all similar things are said to exist potentially and actually in a different sense from that which applies to many other things, e.g., to that which sees or walks or is seen. For of the latter class these predicates can at some time be also truly asserted without qualification; for the seen is so called sometimes because it is being seen, sometimes because it is capable of being seen. But the infinite does not exist potentially in the sense that it will ever actually have separate existence; it exists potentially only for knowledge. For the fact that the process of dividing never comes to an end ensures that this activity exists potentially, but not that the infinite exists separately."

Wilfrid Sellars (essay date 1957)

SOURCE: "Substance and Form in Aristotle," in Journal of Philosophy, Vol. LIV, No. 22, October 24, 1957, pp. 688-99.

[In the following essay, Sellars reviews the nature of substance, form, and matter as discussed by Aristotle, noting ways in which Categories, particularly statements regarding the theory of predication, can help one understand the concepts expressed in Metaphysics.]


In Categories 2 b 4 ff., Aristotle writes, "Everything except primary substance is either predicated of primary substances or is present in them, and if these last did not exist, it would be impossible for anything else to exist."1 By "everything except primary substances" he presumably means, in this context, everything which is either a secondary substance, or belongs in one of the other categories. And he is telling us that while items other than primary substances may legitimately be said to exist, their existence is essentially bound up with the fact that they are either 'predicated of or 'present in' primary substances.

What, exactly, does Aristotle mean by these two technical expressions? Leaving 'predicated of aside, for the moment, let us note some distinctive features of his account of 'present in'. "By being 'present in a subject' I do not mean present as parts are in a whole, but being incapable of existence apart from the said subject" (1 a 24-5). He then tells us (2 a 25 ff.) that "with respect to those things … which are present in a subject, it is generally the case that neither the name nor the definition is predicable of that in which they are present," to which he adds that "though the definition is never predicable, there is nothing, in certain cases, to prevent the name being used" (italics mine). He has just been pointing out that both the name and the definition of the species Man are predicable of the individual,—thus, 'Socrates is a man' and 'Socrates is a two-footed, terrestrial animal'. If we coin the expressions 'nominal predication' and 'full predication' to stand for the difference Aristotle has in mind, the question arises as to what sorts of things are fully predicable of primary substances. The list includes not only the species, but also the genera, proximate and remote. It also includes the differentiae, thus, two-footed and terrestrial. Does it include anything else? Aristotle continues the above quoted passage by giving an example of something which is nominally but not fully predicable of a primary substance. "For instance, white being present in a body, [the word] 'white' is predicated of that in which it is present; the definition, however, of white is never predicated of the body."2

In Categories 4 a 10 ff. Aristotle tells us that "the most distinctive mark of substance appears3 to be that while remaining numerically the same, it is capable of admitting contrary qualities." The question naturally arises, Is Aristotle contrasting materiate substances with items in other categories of being which, also remaining numerically the same, are incapable of admitting contrary qualities? And to this the answer is, Yes. "Thus," he continues, "one and the same color cannot be both white and black. Nor can the same action be both good and bad."

It should now be quite clear that by 'one and the same color'—'a color which is numerically one'—Aristotle does not mean a shade of color, that is to say, a repeatable or universal which is common to many individual things, but a particular, an instance of a shade of color. If we call this particular 'Tom', the idea is that Tom is, say, a white as Socrates is a man, not as Man is an Animal. The doctrine is that of the Phaedo, where (102 D ff.) distinguishing between the large thing, the large in the thing, and The Large Itself. Plato tells us that while the large thing may become small (by losing the large which is in it and, sharing in The Small Itself, acquiring a small to be the small which replaces it), the large in the thing can never be small, nor the small in the thing large.

The view which emerges from these passages is one according to which all predication is built on one fundamental form, namely 'X is a Y'. If X is a primary substance, Y is a secondary substance or thing-kind. But there are other examples of this form—thus,, 'Tom is a white'. Here Tom would be a quality in a 'primary' sense which corresponds to the 'primary' sense of 'substance'. A similar distinction is to be drawn in each of the other categories.' We shall call items such as Tom, qualia, and primary instances of the category of Quantity, quanta.5

There are, then, for Aristotle, at least two dimensions in which the being of items other than primary substances is dependent on the being of primary substances. In one dimension the 'is' of 'This white is' stands to the 'is' of 'This man is' as 'inseparable' to 'separate'.6 What they have in common can be represented by saying that they share the form 'X is a Y'. A second dimension in which beings other than primary substances are dependent on primary substances is concerned with the being of universals. This dimension is brought out by the formula

Man is = Some primary substances are men.

'Man is' is traced to 'This (substance) is a man'. In these terms the significant difference between Plato and Aristotle is that whereas the former takes 'man' to be primarily the proper name of a single entity, Aristotle takes it to be primarily a common name of many individual men (thus, Categories 3 b 15-17) and consequently refuses to treat even its derivative use in, say, 'Man is an animal' as that of a proper name.7


What light does the teaching of the Categories throw on Aristotle's analysis of changing substances into matter and form in the Metaphysics? One thinks right away of the fact that if anything is clear about an Aristotelian form it is that its primary mode of being is to be a this. Certainly the form of a materiate substance is not a universal, for, as Aristotle reiterates, the form is 'the substance of the composite, and the substance of a this must be of the nature of a this and never a universal.8 Two questions obviously arise: (I) Is the form of a materiate substance not only a this, as contrasted with a universal, but a 'primary substance' in the sense of the Categories9? (2) To what extent does the sense in which the form is present in either the composite or the matter correspond to the sense in which, e.g., the white-in-the-thing is present in the white substance?

That the form of a materiate substance is in some sense an 'individual' or 'this' is clear. Does it follow that since it is not a universal, it must be a 'primary substance' in the sense of the Categories? No; for, as we shall see, it can be 'substance' in a derivative sense as being the immanent principle or cause of a primary substance. It can be a this which is a substance as being that by virtue of which the substance in which it is present is a substance in the primary or underivative sense of the term.10 Indeed, it can even be a this in a derivative sense without being a universal, which, after all, is the heart of the matter.

But if a form is a this which is a this and substance only in a derivative sense, what is it in its own character? To use Aristotle's own example, medicine is healthy qua capable of restoring health, but in its own character, it is, say, a concoction of juices. The answer which leaps to mind, though it won't do as it stands, is that the form is, in its own character, a quale (or quantum, or combination of these or other particulars from categories other than substance), but that it is a form not qua quale, but qua that by virtue of which the primary substance in which it is present is a separate being of a certain kind. We seem to find something like this account in Aristotle's treatment of artifacts. Of particular interest in this connection is a passage in the Categories where he writes (3 b 18 ff.):

Yet species and genus do not merely indicate quality, like the term 'white'; 'white' indicates quality and nothing further, but species and genus determine quality with reference to a substance; they signify substance qualitatively differentiated.

To this passage should be related Metaphysics 1042 b 9 ff.,—in which he tells us that the 'principles of the beings of things' are to be found in the attributes with respect to which the various kinds of things or substances differ from one another. To this he adds the necessary reminder that the principle of the being of a substance cannot be found simply in a category other than substance, e.g., quality: "… none of these differentiae is substance, even when coupled with matter, yet it is what is analogous to substance in each case." This remark is, in the first instance, a reference to the view that the difference is to the genus as form to matter; that is to say, the genus is a determinable which the difference makes determinate much as plane figure is made determinate by bounded by three straight lines, and still more determinate by specifying that the lines are equally long. But of even greater significance is the fact that the difference is a difference of a kind of substance, as opposed to "a quality and nothing further," by determining a way of being a substance. For it clearly won't do to treat the category of substance as the highest determinable under which the difference falls, if the difference is construed simply as a quality, for then the category of substance would simply be the category of quality.

How is this to be understood? Aristotle, like all philosophers who take substance seriously, faced a dilemma. This dilemma concerns the relation of thing-kinds or secondary substances to the criteria which things must satisfy in order to belong to these kinds. It is important to see that this dilemma depends in no way on the Socratic-Aristotelian distinction between qualities and qualia, quantities and quanta, etc., though failure to escape between the horns of the dilemma may suggest this multiplication of particulars.

On the one hand, there is a strong temptation to identify 'S1 is a K' with 'S1 is Q1 … Qn', which identification might be expressed by the equation (where S1 is an individual substance, Q1 … Qn its criterion qualities),

S1 is a K = S1 is Q1 … Qn.

The violence this does to our conceptual framework is brought out by the fact that it doesn't make sense to say 'S1 is a Q1'. And no matter how 'complex' we make the adjective 'Q1' it still doesn't make sense to say 'S1 is a Q1.' Even if 'S1 is Ql' were equivalent in meaning to 'S1 is Q1 … Qn', the question 'What kind of thing is S1?' i.e., 'S1 is a what?' is no more answered by 'S1 is Q1' (save by implication) than, as Urmson has pointed out, 'Is this apple good?' is answered by 'This apple is XYZ', where 'XYZ' is the descriptive term which specifies the criteria for good apples.

In particular, it won't do to equate 'S1 is a man' with 'S1 is human', for, outside of the textbooks, 'S1 is human' means 'S1 is like a man' (cf. 'Fido is almost human') or, more usually, like a good man (in some respect relevant to the discussion). Thus 'S1 is human', far from illuminating 'S1 is a man', presupposes it.

Since the question 'S1 is a what?' will not down, the attempt to reduce thing-kind expressions to complex adjectives leads to the introduction of a new (and pseudo-) thing-kind expression, namely 'Substratum'. It is 'a substratum' which is Q1 … Qn. The substratum is a "bare substratum" in that though 'SI is a substratum' professes to answer the question 'Of what kind is the object which is Q1 … Qn?' it fails to do so. Clearly it is words like 'man', 'horse', 'shoe', etc. which properly play this role.11

On the other hand (the second horn of the dilemma) the attempt to distinguish between the thing-kind and its criteria may lead to equally desperate expedients. For if we insist that to say of S1 that it is a K is to characterize S1 in a way which does not amount to characterizing it as Q1 … Qn, we are open at once to the challenge 'Is it then logically possible for there to be a K which isn't Q1 … Qn (although the latter are granted to be the criteria for being a K)?'; while to take the line that 'K' as distinguished from the criteria simply characterizes S as "thingish" or "substantial" is to return to the "bare substratum" of the first horn.

Now the genius of Aristotle (as well as his limitations) is nowhere better illustrated than in his treatment of substance. This becomes clear once we discover how to run between the horns of the above dilemma. And, indeed, all we need to do is face up to the fact that thing-kind words are common names and not a peculiar kind of adjective. Thus, while 'S1 is a K' implies that S is Q1 … Qn, 'K' is by no means "logical shorthand" for "being Q1 … Qn". Q1 … Qn are criteria for the application of 'K' without being "the meaning of 'K"' as XYZ, say, is the criterion for the application of 'good' to apples without being the meaning of 'good' as applied to apples. The point is not simply that there is "free play", "vagueness", or "open texture" in the connection between being a K and the qualities Q1 … Qn. The connection could be ever so tight, so tight that there is a definite set of conditions separately necessary and jointly sufficient to establish that something was a K and still 'K' would play a unique role in discourse, a role which is quite other than that of a complex adjective. Words for thing-kinds are no more shorthand for their criteria, than proper names are shorthand for definite descriptions, which serve as their criteria (cf. Wittgenstein, Investigations, 79).

I have emphasized that thing-kind words are common names. By this I mean that they are common names of individuals, not proper names of universals; and as I have already indicated, I believe that Aristotle saw this and saw it clearly. It is just because 'man' is the common name of individual men that it can "cover the whole being of individual men". ('Man' is no more the name of a part of the individuals it names, than 'Julius Caesar' is the name of a part of Julius Caesar.) Also clearly reflected in his account is the fact that while a shoe may at one time be polished and at. another time scuffed, which we may represent by the form

S1 is Q-at-t

thing-kind words do not have the form

S1 is a K-at-t.

A shoe is not a shoe at a time. Certainly there is a sense in which a piece of paper may be now a letter, now a (toy) aeroplane. But while the paper may come to be arranged in that way which makes it an aeroplane, and continue to be arranged in that way, and then cease to be arranged in that way, the aeroplane simply comes to be, exists throughout the stretch of time, and then ceases to be. To say that the paper is now an aeroplane is to say that the name 'aeroplane' is now appropriately applied to the paper. And since 'aeroplane' is the name of pieces of paper qua arranged in that manner, the name comes to be applicable to the piece of paper (the aeroplane comes to be) when the paper becomes so arranged, and ceases to be applicable (the aeroplane ceases to be) when the paper ceases to be so arranged.

We might put this by saying that aeroplane is predicable of the paper qua arranged, but the material mode of speech and the term 'predicable' should not deceive us. We can, if we like, say that 'aeroplane' means the character of being an aeroplane, and that this character is attributable to the paper qua arranged. The important thing is not to be misled by this manner of speaking into assimilating 'being an aeroplane' to 'being white'.

But not only are thing-kinds not reducible to the qualities which are their criteria, these qualities have, as criteria, their own logical peculiarities. We saw above that a shoe is not a shoe-at-t. It can now be pointed out that not only are animals not animals-at-t but to be a two-footed animal is not to be an animal which is two-footed-at-t. Again when a certain quality, say white, is a criterion quality, its character as criterion for the thing-kind name is reflected in the fact that it has the form 'white-thing' or 'white substance', where these phrases are not to be understood in terms of such contexts as 'What is that white thing over there?' To refer to something as 'a white thing' in the sense of this question is not to imply that the object would cease to be the thing it is if it ceases to be white. For the question has the force of

That thing over there, which is (now) white, of what kind is it? it is a what?

On the other hand, as the form of the criterion-predicate, 'white substance' indicates not only that to be white in this sense is not to be white-at-a-time, but implies that something which was not in this sense white would not be a thing of the relevant kind, i.e., that 'being white' in this sense is a criterion for the applicability of the corresponding common name.


Let us apply these considerations to Aristotle's account of artifacts, for example, a shoe. 'Shoe', then, is a common noun applicable to pieces of leather qua qualified by certain criterion qualities. 'Shoe' is not a complex adjective, nor is it defined by qualities, but by qualities 'determined with reference to substance'. A shoe is a this in that it is a shoe. For to be a this in the primary Aristotelian sense is to be not simply not a universal, but to be an instance of a thing kind.12

It is against this background that we can understand Aristotle's denial that matter is (save in a derivative sense) a this. For while the matter of which a shoe is made is a particular in a broad sense as contrasted with a universal, it is not a this in the sense of 'a K'. Notice that we speak of 'a shoe' but of 'a piece of leather'; 'a statue' but 'a chunk of marble'; and so on. 'Leather', 'marble', 'bronze' are not thing-kind words, and Aristotle's distinction between thises and the matter for thises reflects an important distinction. What Aristotle has in mind is that when you have said of something that it is a piece of leather, you have not classified it under a secondary substance, and that even when you say 'a piece of leather of such and such a size and shape' you have not yet characterized it as a this, though you will have done so by implication if by virtue of being a piece of leather thus qualified, it conforms to the criteria for a thing-kind, e.g., shoe.13

Now if the shoe 'as a whole' is the instance of the secondary substance shoe (a fact which reflects the role of 'shoe' as a common name), what is the form of the shoe as contrasted with its matter? Among the conditions to be met by an answer are the following: (1) The form is not a universal, yet it is not simply a this or primary substance. (2) The form is not a quale, quantum, etc., nor any combination of these, for it is that by virtue of which the shoe is a primary substance; yet it cannot be explained without reference to categories other than substance. The answer, as far as I can see, is to be found by a more careful analysis of the secondary substance shoe. We have been representing it (in the material mode, so to speak) as such and such qualities determined to substance. Would we not, however, better reflect the above analysis if we represented it by such and such qualities determined to substance in leather? If so, it springs to the attention that shoes, after all, can be made of other materials, for the attributes which justify the application of the name 'shoe' to a piece of leather can, at least in principle, be present in these other materials. Thus, the form of shoes taken universally is the secondary substance shoe as represented immediately above ('leathern shoe') without the specification of the material in which the criterion qualities are to be present. On the other hand, the form (taken universally) is not these qualities simpliciter, but these qualities determined with reference to substance (i.e., as criterion qualities for a thing-kind name) in some appropriate material or other. Thus Aristotle can say that the form of this shoe is, in a certain sense, the shoe itself. For, to follow up the above line of thought, the form of this shoe is the shoe itself qua a foot-covering made of some appropriate kind of matter. The form is in this disjunctive sense (indicated by 'some') more 'abstract' than the shoe, but it is not for this reason a universal. Furthermore, the form, in this 'abstract' (disjunctive) way includes the whole being of the individual shoe. The form qua form is incapable of separate existence as disjunctive facts are incapable of existing apart from "basic" facts, but it is not 'present in' the shoe as a quale is present in a primary substance. For the form taken universally is fully predicable of the subject. SI is not only a covering for the feet made of leather, it is a covering for the feet made of some appropriate material or other. The sense, therefore, in which the form of the shoe is present in the shoe, and is an incomplete entity incapable of separate existence, is not to be simply identified with the sense in which qualia, quanta, etc. are present in primary substances, nor is it to be identified with the sense in which universals are incapable of separate existence.14

It is, I think, clear, that something like the above distinctions can be drawn without a commitment to the theory of predication of the Categories. As far as I can see, however, Aristotle remained committed to this theory throughout his career.15 And this is the occasion to admit that Aristotle sometimes seems to think of the form of a materiate substance as a substance which is more truly substance than the substance of which it is the form—particularly in the case of living things, where Human Soul, for example, seems at times to be a thing-kind which is more truly a thing-kind than the materiate universal Man; the soul of Socrates to be in a primary sense a this, and Socrates a this in a derivative sense as having a primary this within him. To be sure, the soul of Socrates would not be primary substance in the full sense of the Categories, for it is incapable of separate existence. But, then, is any being truly capable of separate existence save those incorporeal intelligences which everlastingly think on thought?

That Aristotle could think along these lines was made possible by the fact that his theory of predication provides a built-in way of going from 'this matter is […] 'to 'a […] in this matter'. Is this not the key to Aristotle's claim that whereas 'to be man' is not identical with the essence of man, 'to be soul' is identical with the essence of soul'? For the latter treats souls as items which are not only the essence of the living things to which they belong, but themselves have an essence. What essence? Do we not have here an echo of the Phaedo? of the idea that souls are essentially alive and as alive make the composites to which they belong derivatively alive?16


1 I have found Joseph Owen's important book The Doctrine of Being in the Aristotelian Metaphysics (Toronto: Pontifical Institute of Medieval Studies, 1957) and Ellen Stone Haring's analysis of Metaphysics Z ("Substantial Form in Aristotle's Metaphysics Z," Review of Metaphysics, Vol. 10, 1957) helpful and suggestive, although I ran into the latter too late to give it more than a careful first reading.

2 The Oxford translation, which I have modified slightly, reads: "For instance, 'white' being present in a body is predicated of that in which it is present, for a body is called white: the definition, however, of the color 'white' is never predicable of the body."

3 The "appears" is undoubtedly a tacit reference to the existence of unchanging, immaterial substances. Strictly speaking, however, it is probably incorrect to say that immaterial substances are substances in the sense of the Categories, i.e., in the sense in which substances are contrasted with the qualities, quantities, etc. by which they are characterized. They are, however, beings which 'exist apart'—indeed, more truly apart than the primary substances of the Categories.

4 Cf. Ross, Aristotle, Second Edition, p. 24.

5 A no less explicit and, in certain respects, more interesting formulation of this theory of predication is to be found in Topics 102 b 20 ff. Two points require to be made about the translation: (1) 'White' in 103 b 32 should be 'the (presented) white' (to ekkeimenon leukon) to parallel 'the (presented) man' (to ekkeimenon anthropon) which the translator renders simply by 'a man'. (2) 'Essence' is here the translation of 'ti esti' and has the sense of the 'what it is' or 'identity' of something. To give something's ti esti is to identify it as, say, 'a man' or 'an animal'—or, and this is the crux of the matter, 'a white (quale)' or 'a color (quale)'. In 102 a 32 ff. Aristotle writes, "We should treat as predicates in the category of essence (ti esti) all such things as it would be appropriate to mention in reply to the question 'What is the object before you?"' Notice that the distinction between the first class of predicates and the remaining nine which is drawn in this passage is not that between substance and the various sorts of thing that can be said of substances, but rather between the identity, the ti esti of an item of whatever category in the more familiar sense, and the sort of things that can be said of it.

6 While changeable things must have qualia present in them, and in this sense cannot exist apart from qualia, they can exist apart in the specific sense in which qualia cannot; for primary substances are not present in a subject.

7 The argument of the Categories implies that while we might begin to explicate 'White exists' by saying 'White is = Some primary substances are white', the analysis would not be complete until we said something like 'White is = Some qualia are whites', though Aristotle nowhere explicitly undertakes this reduction.

8 It is perhaps worth nothing that the unmoved movers are with equal certainty not universals. Of what would they be predicated?

9 As contrasted with the use of this and related expressions in other contexts. Thus in Metaphysics VII, 1032 b 1, 1037 a 5, and 1037 b 1, this expression is applied to the form of a materiate substance as the principle by virtue of which the latter is a substance. The form is 'primary' as not itself consisting of matter and form, and as prior to the concrete individual which does consist of matter and form. Yet that the form of a materiate substance in some sense includes its matter will be argued below.

10 It is essential to realize that the idea that the concrete individual is a substance in the primary sense of 'substance' (as having separate existence) is not incompatible with the idea that there is an entity which though a substance in a derivative sense, is nevertheless prior to the concrete individual as a principle of its being.

11 The realization that 'substratum' is a stone where there should be bread, combined with the fact that the question 'S1 is a what?' will not down, soon generates a more subtle scheme. By the simple expedient of coining a new usage according to which the adjective 'white' rests on a postulated common name 'white' so that we can speak of 'a white', and, in general, of 'a Q', bare substrata are avoided by turning S1 into a bundle consisting of a Q1, a Q2 … and a Qn. Since it is a fundamental feature of logic of a set of thing-kind expressions belonging to a given universe of discourse, that no object belongs to more than one kind (unless these kinds are related as genus to species) the introduction of qualia soon leads to the feeling that no quale can be of two kinds which are not related as determinable to determinate. I have trodden this road myself in "Particulars," Philosophy and Phenomenological Research, Vol. 13, 1952, and "The Logic of Complex Particulars," Mind, Vol. 58, 1949. My mistake was in thinking that in the language we actually use things that are complex particulars, and 'thing-kind' words 'abstract' references to sets of simple particulars. I remain convinced, however, that there is a sense in which an ideal description of the world would be in a language of this form. In any event, Aristotle's recognition of whites in addition to white things and whiteness is clearly not motivated by a desire to avoid substrata. Nor was his doctrine of prime matter motivated by logical puzzles relating to predication. That opposite (e.g., a hot) cannot act directly on opposite (e.g., a cold) but only qualified substratum on qualified substratum is a fundamental principle of his Physics. And the very claim that first matter is, as such, 'blank' and incapable of separate existence rather than an empirical stuff such as fire or air, is argued on natural philosophical rather than narrowly logical grounds.

12 In Metaphysics 1049 a 19-b 2, which begins with the familiar characterization of prime matter as "that which is no longer with reference to something else called 'thaten'," Aristotle distinguishes between predication in which the subject is a 'this' (a concrete individual) and predication in which the subject is not a 'this' but, rather, matter. He writes: "For the subject or substratum is differentiated by being a 'this' or not being one; i.e., the substratum of modifications is, e.g., a man, i.e. a body and a soul, while the modification is 'musical' or 'pale'.… Wherever this is so, then, the ultimate subject is a substance; but when this is not so but the predicate is a form and a 'this', the ultimate subject is matter and material substance." The concluding sentence is likely to be misinterpreted and to lead to unnecessary puzzlement unless it is realized that "the predicate is a form and a 'this"' has the sense of "the predicate is 'a K' (e.g., 'a man', 'a shoe', etc.)."

13 It might be thought that 'piece of leather' is a thing-kind expression, even if 'leather' is not. Let me indicate, in an Aristotelian mood, why it is only "in a sense" that this is so. Artifacts are purpose servers. The purpose of shoes, for example—to protect and embellish the feet—is part of the very 'meaning' of 'shoe'. But pieces of leather as such are purpose-servers only by being raw material for direct purpose-servers. The context 'piece of …', 'chunk of …', etc., so characteristic of recipes, turn words for kinds of material ('leather', 'marble', etc.) into expressions which, as far as purpose is concerned, imply at most that their designata can be the material cause of items which, as correctly designated by a proper thing-kind expression (in the universe of discourse of artifacts), are direct purpose-servers. A shoe can, indeed, be part of the matter for, e.g., a store window dummy; yet it remains a purpose-server in its own right. But something which is merely 'a piece of …' is only a purpose-server in a derivative sense. The fact that leather is made doesn't mean that pieces of leather are artifacts in the primary sense of this important Aristotelian expression. Aristotle views even the elements in the context of craftsmanship (including the 'craftsmanship' of living things). It is for this reason that he views pieces of earth, air, etc. as thises only in a derivative sense.

14 That the form component of the materiate universal (secondary substance) man might also be found in other materials is suggested by Metaphysics 1036 a 31 ff.

15 See, for example, Metaphysics 1077 b 5 and 1087 a 17; also 991 a 14.

Joseph Owens (essay date 1957)

SOURCE: "The Problem of Being," in The Doctrine of Being in the Aristotelian "Metaphysics," Pontifical Institute of Metaphysical Studies, 1957, pp. 35-68.

[In the following essay, Owens studies how Medieval metaphysicians interpreted Aristotle's Metaphysics. Owens observes that the two apparently contradictory notions of being identified in Metaphysics (being as either an abstract, empty concept and being as related to the concept of God) were often merged by Medieval Christian thinkers, and he reviews the debate among later critics regarding the possibility of unifying the two concepts.]

To determine whether the notion of Being in Alexander of Hales is Aristotelian or Platonic, a recent historian seeks his criterion in "the gradual separation of the Aristotelian views from the essential and fundamental teachings of Plato."1 He arrives at a clear-cut norm: "Therefore the essential difference between a Platonic and an Aristotelian conception of Being consists in this, that for the former conception, Being as Being is the ens perfectissimum; while for the latter, Being as Being is the ens commune."2

In its application to the mediaeval thinker, the norm places two alternatives. The one question is: "Does Alexander give the concept of Being a sense that makes it the proper concept of God?"3 If so, his notion of Being is Platonic. The opposite query runs: "Does our author see in the concept of Being the concept most abstract and most empty of content, which, because it has the least content, has the widest extension?"4 In this case his doctrine is properly Aristotelian.

Back of the criterion lies an easily recognizable view of the Aristotelian Primary Philosophy.5

Towards the close of the nineteenth century, Natorp called attention—apparently for the first time—to an "insufferable contradiction" in the traditional Metaphysics. He distinguished two series of texts. These expressed "mutually exclusive" conceptions of the Primary Philosophy. Natorp proceeded to excise the one set of these texts as Platonizing additions inserted by early Peripatetics.6

In strong reaction to so violent a method, Zeller pointed out that the contradiction emerged from the most fundamental of the Stagirite's doctrines. It was too deeply rooted in the whole Aristotelian philosophy to be set aside by philological criticism of certain texts.7

In the present century, Jaeger has sought a more reasonable and primarily philosophical8 solution. The Platonizing character of the texts becomes a mark of their authenticity.9 The two contradictory notions of the Primary Philosophy are actually present in the course of Aristotle's own development. There is an earlier view, which is Platonic; and there is a later one, which is properly Aristotelian. In the earlier stage, the 'object"10 of the science is a particular kind of Being—namely, supersensible or immobile Being. In the later conception, the object is not a particular type of Being, but Being in general, applicable to sensible and supersensible Being alike.11

Should this theory of the Primary Philosophy be historically correct, it will necessarily have important repercussions in any estimate of mediaeval metaphysics.

What are the consequences involved?

They seem quite evident. If a philosopher of the middle ages conceives metaphysics as the science of the Being richest in comprehension, he is thinking in a Platonic direction. If, on the other hand, he agrees that Being as Being means the Being which is widest in extension but most empty in comprehension, he is following the later and properly Aristotelian lead. The historical background restricts the question to the interpretation in the West of the newly-acquired Aristotelian text. For the study of metaphysics as a distinct science in the university circles of the middle ages was occasioned by the spread of that text in Latin translation during the first three quarters of the thirteenth century.12 In a comparatively short time the influence of the Stagirite had altered the whole external structure and technique of Christian thought.13 Accordingly, if a Christian metaphysician working in this milieu took for the subject of his science Being in general—in the sense of the 'most abstract and empty of concepts,' he was drawing the properly Aristotelian inspiration out of the texts from which he was learning his technique. But if—helped largely by the influence of traditional Augustinian thought—he equated the subject of metaphysics with the concept of God, he was interpreting the text according to the Stagirite's earlier and Platonic leanings. Such, at least, seems the way in which the above-mentioned criterion has been applied to Alexander of Hales.14

Some serious misgivings arise after a little reflection on this situation. How could any mediaeval thinker look upon Being as "the concept most abstract and most empty of content"? To the mentality of the age, untouched by Idealism, Being in some way included everything. Nothing could be added to it, neither difference nor accident. It included all its differences. In this sense the mediaeval philosophers interpreted Aristotle's doctrine that Being is not a genus.15 Unlike a generic concept, Being for these thinkers did not decrease in content according to its increase in extension. Besides enjoying the widest possible extension, it possessed in one way or another the greatest possible comprehension. It was far from being an 'empty' concept.16

On the other hand, was any Christian thinker of the middle ages free to identify the subject of metaphysics with the God of his religious faith?

Etienne Gilson has pointed out the profound difference between the Greek and the Christian notions of Being.17 The mediaeval philosophers, as they approached the Aristotelian treatises, were already equipped with the belief in a God whose very name was Being. I am who am was the way in which He had revealed Himself to Moses.18 For the Christian thinker, God was the primary and perfect instance of Being.

But this supreme instance of Being, besides being triune, was an omnipotent and sovereignly free Creator.19 In the natural as well as in the supernatural order, the nature of the First Being transcended human comprehension. Such a Being could hardly be conceived as forming the subject of a specifically human science.20 The subject of metaphysics, when brought formally to the attention of a Christian philosopher, required location in a kind of Being other than the proper nature of the primary and all-perfect type.

Neither, then, of the opposite conceptions of the Primary Philosophy seems acceptable in the mediaeval world.

In point of historical fact, the leading metaphysicians of the middle ages agreed in declaring that Being as Being was the subject of their science. They understood it to include in some way all the differences of Being. It was not an 'empty' concept. But they distinguished it sharply from the primary Being.21 They knew that Aristotle had spoken of the Primary Philosophy as the science of the highest causes and as the science of the separate Entities. They felt obliged to justify their position and to explain in various ways these other formulae of the Stagirite.

Albert the Great, for instance, had no patience with the Latin thinkers who tried to combine into one the three conceptions of metaphysics.22 The theory that God is the subject of this science he considered frankly Platonic and false.23

St. Thomas Aquinas explained that while the science treats of the first causes and the separate substances, ens commune alone can be its subject.24

Siger of Brabant declared, after considering the three views, that "the principles of a thing are sometimes not the principles of its discipline." God, though the first principle of Being, is not "the principle of Being according as it is Being."25

Duns Scotus discusses at considerable length the problems involved in the different conceptions.26 The interpretation of metaphysics as the science of Being qua Being—in the sense of Being in communi27—is for him, as for Siger, the view of Avicenna;28 while the doctrine that God and the separate substances are the subject of the science, is regarded as the position of Averroes.29 Scotus also discusses the view that metaphysics is the science of substance.30 The notion of the primary causes as the subject seems to merge for him in the conception of Being in communi.31 This latter view is the one to which he himself adheres.32

Nor does William of Ockham think differently on this particular point, as far as can be gathered from his teaching about human knowledge of God and substance. Both are known through ens communissimum.33

These mediaeval philosophers, consequently, were well aware of the different conceptions regarding the Aristotelian Primary Philosophy. If they were concerned merely with the neatest formula to delineate the science of metaphysics, they would not be raising any specially important issue. But if they were encountering trouble in expressing their Christian notion of Being in Aristotelian terms, might they not be facing a much more serious problem? Might they not be forcing their own conception of Being into formulae which could not contain it, and which under the pressure burst open in various ways?

In point of fact, the different Christian thinkers of the thirteenth and fourteenth centuries developed radically divergent metaphysics.34 Yet all learned their technique from Aristotle, and all couched their theses in his formulae. They held in common the doctrine of God and creatures taught by their faith. How can the all-pervasive differences in their metaphysics be explained? An adequate explanation must be given if the mediaeval controversies are to be understood. And not only the lack of agreement in mediaeval procedure, but also the subsequent discouraging history of the science up to the present day seems rooted in these diverging interpretations of the Aristotelian text at the critical period in the inauguration of Western metaphysics.

The first step in solving this problem must be a clear understanding of the doctrine of Being actually contained in the text which confronted the mediaeval thinkers.

In the Metaphysics itself, the study of Being is expressed in various ways. Sometimes the Primary Philosophy is described as the science that treats of the highest principles and causes of things.35 More specifically it seems designated as the inquiry into the causes of Being qua Being.36 It is called the science which deals universally with Being qua Being, and not with particular Being.37 Again, it is delimited to divine and immobile Being, and named 'theology'.38 In this sense it deals with Being qua Being, which now seems to become the equivalent of separate Being.39 In other places the Primary Philosophy is the science of ousia,40 of the primary ousia,41 of the causes of ousiae,42 or of the causes of the visible divine things.43 Again, it is the science of truth.44 In the Physics it is the science of form.45

Can all these different modes of expression denote the same doctrine of Being?

Aristotle himself appears conscious of no inconsistency or contradiction in these various designations. Even when raising a question that today seems to bring an antinomy to the fore, he writes as though unaware of any real difficulty.46 He does not seem in the least perturbed by what many modern commentators find embarrassing if not impossible.

Yet the texts have given rise to considerable difficulty in the history of Aristotelian interpretation. A glance over the Greek and the modern presentations of these formulae will help articulate the problem back of the mediaeval efforts to determine precisely the subject of metaphysics.

The long tradition of the Greek commentators seems to have been quite unanimous in interpreting the Aristotelian Being. As studied by the Primary Philosophy, Being qua Being,—Being in its own proper nature— somehow referred to a definite type of Being and ultimately meant divine and separate Being.

The Greek tradition may be studied as far back as Theophrastus and Eudemus, both disciples of Aristotle.

Theophrastus was the friend and heir of the Stagirite. He was not a commentator on Aristotle. But in the short treatise known as his Metaphysics, he deals with some of the leading problems of the Primary Philosophy.47 As the immediate successor of his master in the Peripatetic school, he is a witness of the Aristotelian tradition in its earliest stages.

How, and by what distinguishing marks, should we delimit the study of first principles? … the study of first principles is definite and unchanging; which is the reason also why men describe it as concerned with objects of reason, not of sense, on the ground that these are unmovable and unchangeable, and why, in general, too, they think it a more dignified and greater study.

… It is, at all events, more reasonable to suppose that there is a connexion and that the universe is not a mere series of episodes, but some things are, so...

(The entire section is 51243 words.)

Practical Science: Ethics And Politics

G. R. G. Mure (essay date 1932)

SOURCE: "Practical Man: Politics," in Aristotle, Ernest Benn Limited, 1932, pp. 157-62.

[In the following excerpt, Mure surveys Aristotle's Politics, asserting that Aristotle criticizes and completes the "broad outline of Platonic theory." Mure notes Aristotle's views on the role of the state, classes, and citizenship, and comments on the similarities and differences between Aristotle's and Plato's political philosophies.]

… Aristotle's Politics contains several sets of lectures, and some of them are fragmentary.1 But no other work of his displays more clearly the vast masses of...

(The entire section is 35535 words.)

Further Reading

Allan, D. J. "The Shape of Wisdom." In The Philosophy of Aristotle, second edition, pp. 70-29. London: Oxford University Press, 1970.

Outlines the topics covered in Metaphysics, focusing on the nature of being.

Allen, Sister Prudence. "Aristotle." In The Concept of Woman: The Aristotelian Revolution; 750 B.C.-A.D. 1250, pp. 83-126. Grand Rapids, Mich.: William B. Eerdmans Publishing Co., 1985.

Examines in detail the manner by which Aristotle develops, through several works including Metaphysics, the concept of sexual polarity.

Bambrough, Renford. "Aristotle on Justice: A Paradigm of Philosophy." In New Essays...

(The entire section is 605 words.)