Aristotle as a Source for St. Thomas's Doctrine of esse
Lawrence Dewan, O.P.
 The Idea of Sources;  Thomas's Sources;  The 20th Century Problem of Aristotle as Source (Gilson);  Thomas on Aristotle;  The Real Greeks and Existence.
The Idea of Sources
What is a source? We are speaking of communication among minds, and communication over periods of centuries.(1) What kind of causality is involved? The strongest would seem to be the sort of thing that a teacher does, relative to pupils.(2)
The topic relates to progress in philosophy, and the nature of such progress. Aristotle gives us something of an example in Metaph. 1, where he reviews the doctrines of earlier thinkers on the causes. Is it a sort of "material causality" (as to the nature of the contribution of all the philosophers on all the kinds of causes) that is involved?(3) As Aristotle says, all of the causes have been touched upon, but none has been adequately spoken of. And Thomas, echoing Aristotle, speaks of the early philosophers advancing slowly and hesitantly.(4) Rather than mere material causality, we should speak of the "imperfect act" which pertains to motion, change, progress.(5) What is the agent in such change? Aristotle speaks of the early thinkers being forced by truth itself, and Thomas agrees, e.g., concerning the doctrine of divine immutability.(6) This is to say that it is the divine light, in things and in us, that makes us "self-improvers".(7)
But here, considering sources, we are thinking more particularly of the role of earlier thinkers as giving us a key insight. What about Aristotle and the division of being by act and potency? There is already a Platonic appreciation of form, as seen in the story of Socrates' education, in the Phaedo. There is development within Plato's lifetime, and there are seeds, in Plato, of the doctrine of Aristotle: one thinks of the earth-born giants' definition of being as power, dunamis, in the Sophist.(8) We have an appreciation, with Aristotle, of the primacy of form as act, and of hierarchy of causes. Surely, that is a set of doctrines which is the "seed" of much subsequent thought. Perhaps, in speaking of "sources", we should be speaking of "seeds". Plato and Aristotle are "seminal" relative to St. Thomas's doctrine of being.
When one thinks of the rapid and often obscure treatises of Aristotle,(9) or even of the brief and not too clear treatises of Boethius, and compares them to the ST 1, with its orderly procedure and multitude of relatively clear arguments, one cannot help speaking of "progress" in philosophy. But what is the exact nature of such progress? Is it really "in philosophy", or is it in "pedagogical adequacy"? Or are these sometimes the same?
We might also, as to the importance of seeds, remember Thomas paraphrasing Aristotle:
… who moves away ever so little from the truth regarding a principle, going further, becomes ten thousand times more distant from the truth: and this is because all subsequent [things] depend on their beginnings. And this appears most of all in an error as to roads: because the person who strays ever so little from the right road, going further goes much further [astray]….
And the cause of this is that a principle [or beginning], though it is small in magnitude, is nevertheless great in power [virtute], as from a small seed a great tree is produced; and hence it is that that which is small in the beginning is multiplied in the end, because it arrives at the whole of that to which the power of the principle extends, whether that [principle] be true or false.(10)
What I would underline is that, seeing the seed, one usually would not appreciate how much depends on it. Particularly in matters intellectual, what one person is able to appreciate as implying much more, another will fail to grasp as seminal at all.
One can hardly speak of sources in the 13th century without speaking of Aristotle. On the other hand, he is filtered through many minds in coming to the 13th century. Thomas's doctrine of being obviously owes much to Avicenna.(11) But he also criticizes Avicenna in favour of Aristotle.(12) He criticizes Averroes in favour of Aristotle.(13) He differs from Albert the Great on the meaning of Aristotle's metaphysics and natural theology.(14) We must ask Thomas what, at the end of his life, he thinks is the real doctrine of Aristotle.(15) That is a first step, at least, in attempting to say what he received from Aristotle. And on the score of the doctrine of being, I would think that the idea of metaphysics, and the role of the division of being by act and potency, loom very large, especially as regards the doctrine of creation and the importance and nature of the act of being.
One primary consideration, then, for anyone speaking of Thomas's sources surely is Thomas's own presentations of past authors with whom he agrees. Of course, one may always come to the conclusion that the agreement was a comedy of errors, and that it was only by misunderstanding the earlier thinker that Thomas was able to agree with him. But the work must be done.
The 20th Century Problem of Aristotle as Source (Gilson)
If we consider the presentation of the history of philosophy given in De substantiis separatis ["SS"] as regards the doctrine of separate substances, the condition of their nature and their mode of existing, wherein Plato and Aristotle are seen as the high-point, and other subsequent philosophers are seen as inferior to them in one respect or another, it seems clear that Thomas sees himself as one of the "sequaces" of these two philosophers. They have rightly grasped the mode of production which we call "creation", and the ontology proper to the creature as creature, a potency and act composition with the thing's own form as potential relative to its act of being.(16)
However, in the case of Aristotle, it is very common to find someone claiming that Aristotle's first mover is only a final cause.(17) Obviously, that is not how Thomas reads Aristotle: for Thomas, the God of Aristotle is both efficient and final cause, not only of the movement of the heavens, but of their very substance.(18) But the only way to find that Aristotle is a genuine "source" of Thomas in this regard is to find that Aristotle truly held that the first mover was also an efficient cause. I.e. it can be true that only the final cause can be an unmoved mover. But this does not exclude the efficient cause from being an unmoved mover, if the final cause can be identical with the efficient cause. And that (I submit) is what Aristotle presented as really his own position.(19)
As regards the doctrine of esse, one must be clear on what that doctrine is, in the writings of Thomas himself. Then one will be in a position to see it or its "forerunners" in other authors. If Thomas finds it in Plato and Aristotle, could that be because it is there? If it is difficult to recognize, and to give a correct account of, even in Thomas's own writings, then perhaps those who have such difficulty are simply not "up to" recognizing it in less well developed presentations.(20)
There is a general problem, "always with us", as to what the proper interpretation of Aristotle is. Not merely now, but in Thomas's own time, there was sharp disagreement. Thomas's teacher, Albert, at the time he was teaching Thomas, held that there was no doctrine of creation in Aristotle. Thomas, fresh from Albert's classes, disagrees.(21)
However, in the 20th century we have seen a special form of criticism of Aristotle and interpretation of Thomas which makes it all the more difficult to contend that Thomas derives, in an important sense, his doctrine of being from Aristotle. I refer to the line of thinking developed by Étienne Gilson. It is linked to the discussion of the existence and nature of Christian philosophy. Gilson saw in the doctrine of creation a crucial difference between the philosophy one finds among the ancient Greeks, and the philosophy which eventually develops among Jews, Moslems, and Christians.(22) Consider the Aristotle Gilson presents in God and Philosophy, during the writing of which, as he tells us,(23) he really began to appreciate the doctrine of esse in St. Thomas:
The world of Aristotle is there, as something that has always been and always will be. It is an eternally necessary and a necessarily eternal world. The problem for us is therefore not to know how it has come into being but to understand what happens in it and consequently what it is. At the summit of the Aristotelian universe is not an Idea, but a self-subsisting and eternal Act of thinking. Let us call it Thought: a divine self-thinking Thought. Below it are the concentric heavenly spheres, each of which is eternally moved by a distinct Intelligence, which itself is a distinct god. From the eternal motion of these spheres the generation and corruption, that is, the birth and death, of all earthly things are eternally caused. Obviously, in such a doctrine, the theological interpretation of the world is one with its philosophical and scientific explanation. The only question is: can we still have a religion? The pure Act of the self-thinking Thought eternally thinks of itself, but never of us. The supreme god of Aristotle has not made this world of ours; he does not even know it as distinct from himself, nor, consequently, can he take care of any one of the beings or things that are in it...(24)
This is Aristotle as Gilson conceived of him. There is no doctrine of creation here. Notice how the point that the problem in such a world does not and cannot bear upon the "coming to be" of the world has been tied to the fact that the world has always been and always will be, and this by virtue of necessity. Gilson seems to identify readily such a situation with the absence of a doctrine of creation. But if we say, with St. Thomas, that God might have created an absolutely necessary and eternal universe, we have to explain the existence of such a creature, if not its "coming into" being.(25) Let us not lose sight of the fact that Gilson has argued this way. It suggests he has a rather "physical", as opposed to a metaphysical, conception of the esse of creatures: esse as terminus of generation (at least at the level of imagination).
After the war (1948), Gilson published L'Être et l'essence and Being and Some Philosophers. In them, the ancient Greek philosophers, Plato and Aristotle, are seen as teaching doctrines of being which leave existence out of account.(26) This ties in with the supposed obliviousness of the Greeks to the problem of creation, i.e. the question of the very existence of the universe. Such a stance has ramifications. What is one to do with the presentation of these Greeks by so astute a metaphysician as Thomas Aquinas? There are texts in which he attributes to them a causality of being which cannot be anything but creation. Gilson developed a reading of such texts based on two different senses of "cause of being". He claimed that Thomas was well aware of the absence of a doctrine of creation in Plato and Aristotle, but he saw Thomas as able to credit them with an appreciation of a sort of universal causality of being. Thomas was presented, at the most fundamental level, as enveloping the Greek, and especially Aristotelian doctrine of being, in a more comprehensive metaphysical vision, the vision of created existence.
I have elsewhere shown, I believe, the impossibility of Gilson's reading of Thomas on these issues.(27) For the present, it is enough to say that Gilson seriously neglected the presentation of Plato and Aristotle in SS. There, it is clear that Thomas reads Aristotle, as well as Plato, as teaching a doctrine of the mode of production we call "creation".(28) Moreover, he attributes to them an ontology of created being which, while it lacks later technical conceptions, nevertheless sees a composition within created beings which can only be identified with the composition of esse and form.(29) Thomas sees this as the fundamental message of the distinction between act and potency as a proper division of being as being.
Still, it is a sobering thought that so astute an historian of Christian philosophy could take texts of Thomas Aquinas, in which the author has the express intention of presenting philosophers as teaching creation, and fail to see creation being presented. It says something about the subtlety of the metaphysics of creation, but also about the pressures of public academic debate.
Thomas on Aristotle
Here I will simply recall one set of texts, and that taken from a commentary on Aristotle. I do this because Gilson took the position that Thomas restrained himself in these commentaries and said as little as possible about his own larger metaphysical vision.(30) We should first visit Thomas at In Phys. ["CP"] 8.2 (ed. Maggiolo, #972-975), concerning Aristotle, Phys. 8.1 (251a8-17).
In this well-known CP passage, Thomas notes that because Aristotle holds rightly that movement presupposes the existence of the movable subject,(31) Averroes takes the occasion to speak against the things we (Christians) hold by faith about creation. After relating the arguments of Averroes, and showing their inapplicability to creation, Thomas adds:
Nor is this [teaching of Averroes] in accordance with the intention of Aristotle [secundum intentionem Aristotelis]. For he proves in Metaph. 2 that that which is maximally true and maximally a being [maxime ens] is the cause of being [causa essendi] for all existents [existentibus]; hence, the very being in potency [hoc ipsum esse in potentia] which primary matter has, results as being derived from the first principle of being [sequitur derivatum esse a primo essendi principio], which is the maximal being [maxime ens]. Therefore, it is not necessary that something be presupposed to its [the maximal being's] action, that is not produced by it. [para. 974 ]
Obviously, Thomas reads in Aristotle the very doctrine of creation which he himself presents in such a text as the Fourth Way.(32)
Later in the same discussion, where he refers to creation as the production of totum ens, he recalls the history of appreciation of causal universality, and finishes with the case of Plato and Aristotle:
… the last [philosophers], such as Plato and Aristotle, arrived at the knowledge of the principle of all being [principium totius esse]. [para. 975 ]
Who could doubt the existential and creational import of the term "esse" here? And we are speaking, not only of Aristotle, but also of Plato to the extent that Thomas knew him.
Next we note the very next lesson, CP 8.3 (995 -996 ), concerning Aristotle, Phys. 8.1 (252a33-252b7). Aristotle is saying that it is not always the case that when one arrives at what always is or always happens, that one has reached the principle. Some things always are, and yet are caused to be. Thomas take it upon himself to add:
What is said here must be most carefully noted [valde notandum]; because, as is had in Metaph. 2, the disposition of things in being [esse] and in truth is the same. Therefore, just as some things are always true and nevertheless have a cause of their truth, so also Aristotle understood [Aristoteles intellexit] that there were some perpetual beings [aliqua semper entia], viz. the heavenly bodies and the separate substances, which nevertheless have a cause of their being [causam sui esse].
From which it is clear that though Aristotle held the eternity of the world, nevertheless he did not believe that God is not the cause of being [causa essendi] of the world itself, but merely the cause of movement as some said.
What could be clearer?
Our third passage is in CP 8.21 where Thomas takes Averroes to task for his criticism of Alexander of Aphrodisias. Alexander is presented by Averroes as saying that the heavenly body acquires eternity from the separate mover which is of infinite power, just as [it acquires] perpetuity of movement. The fact that the heavenly body endures forever derives from the infinity of the separate mover. Averroes claimed that it is impossible to acquire perpetuity of being from another. This is because one would be maintaining that what is in itself corruptible is rendered eternal. Instead of saying what Alexander says, Averroes proposes saying that there is no potency whatsoever as regards being in the celestial body, only a potency regarding place.
Thomas replies defending Alexander. What Averroes says is not only false but is also against the intention of Aristotle. Leaving aside Thomas's own direct refutation, let us see what he takes to be the position of Aristotle. He refers to De Caelo 1 [12; Thos., Lect. XXVII], where Aristotle uses in a demonstration the argument that the heavenly body has a potency or power [potentiam vel virtutem] as regards always existing [ut sit semper].(33) Thus one cannot evade the difficulty, as Averroes tried to do, by saying that in the celestial body there is no power as regards being [potentia essendi].
Thomas then goes on to consider the worth of the position of Alexander, viz. that the celestial body acquires eternity from another. Averroes would have been right to criticize Alexander if Alexander had said that there is in the heavenly body a potency to being and to not being. But he does not so envisage the heavenly body. Rather, he says that it is something not having being by itself [quasi non habens a se esse].
At this point Thomas says:
For everything which is not its own esse participates esse from the first cause, which is its own esse. Hence also he [Averroes] himself in the book De substantia orbis affirms that God is the cause of the heavens not only as regards its movement, but also as regards its substance: which is not the case save because from it it has esse. But it does not have esse other than perpetual from him; and therefore it has perpetuity from another. And the things said by Aristotle harmonize [consonant] with this: he says in Metaph. 5 and above in the beginning of bk. 8 that some things are necessary which have a cause of their necessity. This being supposed, the solution is plain, in accordance with the intention of Alexander, that just as the celestial body has movement [moveri] from another, so also [it has] being [esse]. Hence, just as the perpetual movement demonstrates the infinite power of the mover, but not of the movable thing, so also the perpetual duration demonstrates the infinite power of the cause from which it [the movable] has esse. [CP 8.21 (1154 )]
My interest here is simply in the way Thomas discusses a problem of existence in commenting on the Physics of Aristotle. Far from Aristotle's Metaphysics being reduced to non-existential physics (a position taken by Gilson in BSP),(34) Thomas sees genuinely existential questions raised by the procedure of Aristotle in the Physics. Does anyone doubt that we have to do here with Thomas's conception of the act of being, and with creation? And that it is all relevant to what he thinks Aristotle means?
The Real Greeks and Existence
However, while it is easy, pace Gilson, to find Thomas attributing to Aristotle Thomas's own doctrine of esse,(35) this is not likely to convince the listener that Aristotle is really the source of this doctrine, even in an inchoate way, if the listener has a conception of "the true Aristotle" which precludes his having held such a doctrine. The conclusion will be, rather, that Thomas is reading his own doctrine, whatever sources it may have in other thinkers, into Aristotle. Accordingly, the last part of my paper must bear upon the ancient Greeks, Aristotle in particular, in order to suggest that their interest in being as existence was fundamental.(36) This is, of course, a project all in itself, and here I can only point out a few "hot spots".
One general point might be helpful. In his doctrine of being, Thomas treats God as the cause of being in its entirety, being as a nature (though with a less than generic unity).(37) Thus, God is the cause of the proper differences of being, which are the necessary and the contingent. Proceeding from the bottom up, I would say that an interest in reality precisely in terms of the necessary and the contingent, the permanent and the temporary, is an interest in being as being.
[Consider the question of providence and contingency in SCG. We see once again the basic argument:
It pertains to divine providence that the grades of being which are possible be fulfilled, as is clear from what has been said [in the preceding chapter on goodness]. But being is divided by the contingent and the necessary, and it is a proper division of being [Ens autem dividitur per contingens et necessarium: et est per se divisio entis]. If therefore divine providence excluded all contingency, not all the grades of beings would be preserved.(38)
Such texts are not exceptions. Rather, this is the constant teaching of Thomas Aquinas.(39) In Thomas Aquinas's Commentary on Aristotle's Metaphysics, one finds a remarkable treatment of the implications of divine providence. It occurs in Book 6, where Aristotle has just set aside from his theological philosophy(40) the study of being by coincidence [to on … to kata sumbebékos].(41) Does not this position of Aristotle's, in that it acknowledges the existence of mere haphazard, destroy the doctrine of providence? Does not providence suggest that everything happens of necessity? After all, divine providence cannot fail.
Thomas solves as follows:
 But one must know that on the same cause depends the effect and all those [items] which are essential accidents [per se accidentia] of that effect. For example, just as man is [caused] by nature, so also are all his essential accidents, such as capability of laughter, and susceptibility to mental discipline. But if some cause does not make man, unqualifiedly, but [makes] man such, it will not belong to it to constitute those things which are the essential accidents of man, but merely to take advantage of them. For example, the ruler [politicus] makes a man a good citizen [civilem]; still, he does not make him to be susceptible to discipline of the mind; rather, he makes use of that property of [man] in order to make of him a good citizen.
 But, as has been said, being inasmuch as it is being [ens inquantum ens est] has as cause God himself; hence, just as to the divine providence being itself [ipsum ens] is submitted, so also are all the accidents of being as being, among which are the necessary and the contingent. Therefore, to divine providence it pertains, not merely to make this being, but that it give to it contingence or necessity...(42)
And Thomas goes on to make the point that no other cause gives to its effects the modes of necessity and contingency; this is proper to the cause of being as being.(43)]
Suppose we begin with the Presocratics. What their own real interests were is debated. Joseph Owens presents Heraclitus as primarily interested in moral philosophy. He presents Thales as, in the eyes of Aristotle, "the beginning of natural philosophy". Only on this point, says Owens, does Thales deserve a place in the history of philosophy.(44) This in itself is odd. Aristotle actually sees the Presocratics, and this includes Thales, as his predecessors in metaphysics. They were seeking, he tells us, the elements of being as being.(45)
But what does he tell us about the doctrine of these thinkers? One thing on which they all agreed is that nothing comes to be or ceases to be. Now, there is a proposition with an obvious existential interest! In Metaphysics 1.3, discussing the thought of his predecessors, he says:
... let us call to our aid those who have attacked the investigation of being [ton onton] and philosophized about reality [peri tés alétheias] before us. For obviously they too speak of certain principles and causes; to go over their views, then, will be of profit to the present inquiry, for we shall either find another kind of cause, or be more convinced of the correctness of those which we now maintain.(46)
Of the first philosophers, then, most thought the principles which were of the nature of matter were the only principles of all things. That of which all things that are consist [ex hou gar estin hapanta ta onta] , the first from which they come to be, the last into which they are resolved (the substance remaining, but changing in its modifications), this they say is the element and this the principle of things [ton onton], and therefore they think nothing is either generated or destroyed, since this sort of entity [phuseos](47) is always conserved, as we say Socrates neither comes to be absolutely when he comes to be beautiful or musical, nor ceases to be when he loses these characteristics, because the substratum, Socrates himself, remains. Just so they say nothing else comes to be or ceases to be; for there must be some entity [phusin] - either one or more than one - from which all other things come to be, it being conserved.(48)
A little later,(49) in introducing Parmenides, Aristotle notes that the doctrine is that the one and nature as a whole is unchanging, not merely as regards generation and corruption (for this [doctrine] is ancient, and all agree on it), but as regards all types of change. Thus, we see the interest in change and permanence, and the common view that nothing comes to be or ceases to be, in the unqualified sense.
I would say that the entire interest in change and permanence is, as such, existential. Obviously, it gives rise to an interest in essence, precisely as recipe for permanence. It is a mistake to conceive of essence primarily on the model of mathematical beauty, as that which in itself pleases the mind. Essence is primarily principle of being, i.e. of permanence. Thus Gilson himself, in BSP, distinguishes the existential character of Thomistic metaphysics from the 20th century view called "existentialism", and even from what Kierkegaard meant by "existence". Kierkegaard mistook existence in time for existence as such. Gilson stresses man's already partaking of "eternity", and tells us at this point:
The current view of the world as of a realm of progressively decaying and wearing away beings expresses just the reverse of what reality actually is. It betrays reality at least in so far as actual being entails actual existence, for, indeed, not to pass away, but to be for ever and ever, is what it is to exist.(50)
Let us move to Plato. I will touch on the Phaedo, the Timaeus, and the Sophist.
The Phaedo, while ultimately focusing on the immortality of the soul, is a statement of an entirely encompassing philosophy. What philosophy is, what it is to be a philosopher, what virtue is: all such questions are reduced to the divine and what it is to communicate with the divine. However, for our present purpose, let us focus on the question of immortality. It is evidently an existential question. I.e. it has to do with temporality and permanence. Its ultimate solution requires two steps. The first is relatively simple: the answer to Simmias is that the [human] soul is a subsisting thing, not a mere inherent such as a harmony. Already here(51) we are dealing with the question of modes of being,(52) an issue of which Plato is very much aware, as we will see in the Timaeus. Still, it is with the problem of Cebes that we come to the really profound exploration. Given that the soul is subsistent, how can we be sure that it is incorruptible?
The language of the reply of Socrates should be studied. We are confronted with one of the great texts of all times:
Socrates paused for some time and was absorbed in thought. Then he said: "It is no small thing that you seek; for the cause of generation and decay [peri geneseos kai phthoras tén aitian] must be completely investigated…." [95E-96A]
We hear what Socrates expected to learn from the wisdom called "investigation of nature":
I thought it was a glorious thing to know the causes of everything, why each thing comes into being and why it perishes and why it exists [dia ti gignetai hekaston kai dia ti apollutai kai dia ti esti]. [96A-B]
He sees that he is not being given adequate answers to these questions. The method of reply he got was that of juxtaposition and separation, an entirely mechanical approach. He does not change the question:
And I no longer believe that I know by this method even how one is generated or, in a word how anything is generated or is destroyed or exists [di' ho ti gignetai é apollutai é esti], and I no longer admit this method, but have another confused way of my own. [97B]
It occurs to me that we are so mesmerized by the idea of creation that we soften the conception of generation and corruption, making it "only a change". There should be no hesitation in affirming that to be corrupted is to cease to be. Such discussion is thoroughly existential.(53)
Would that we had time to accompany Socrates on the entire intellectual journey he here presents, with his enthusiasm in first discovering the teaching of Anaxagoras. Mind is the cause of all, so that everything is as it is because that is best:
So if anyone wishes to find the cause of the generation or destruction or existence of a particular thing [peri hekastou, hopé gignetai hé apollutai hé esti, he must find out what sort of existence, or passive state of any kind, or activity is best for it [hopé beltiston auto estin hé einai hé allo hotioun paschein é poiein]. [97C]
I am glad to see Fowler translating "einai" as "existence".
We know that Socrates is disappointed with Anaxagoras, simply because the latter did not actually carry out the program, but reverted to the old ways of explaining. And we remember that in his "second voyage" [99D] Socrates focused on logoi, "conceptions", in order to view "the truth of beings [ton onton tén alétheian]" [99E]. He begins with "absolute beauty and good and greatness and the like", and presents these as the very type of the cause of being: nothing else make beautiful things beautiful but the presence or communion [eite parousia eite koinonia] of absolute beauty. [100D] The beautiful thing partakes of or participates [metechei] absolute beauty: this is the view of causality presented. [100C]
But the point for us is that we are approaching the causality of existence. What we eventually develop is the notion of a nature which, though it is not life itself, nevertheless is inseparable from life itself: on the model that snow is not coldness, but is inseparable from it, that fire is not heat, but is inseparable from it, and that two is not evenness, but is inseparable from it. This is a somewhat different, even secondary, mode of being a cause, a "why". [105B-C] The soul is shown to be, in such a way, a cause of life, and so imperishable. [106C-E] Surely the existential interest here is too clear to require much stressing.
Let us consider some other Platonic texts. In the Timaeus, the first presentation of the universe is in terms of the always being, apprehensible by thought, and the always becoming, object of belief and sensation. The universe is a thing which becomes, but is modeled on the eternal. [27D-29A] Later, in explaining the so-called elements such as sensibly apprehended fire, he tells us that they are "such-es", not "this-es". Ontologically, even the characterless receptacle is superior to them, since it is a "this". Both, of course, are inferior to the Idea. Regarding these three, Plato speaks explicitly of three ways of being.(54) - The interest in permanence and perishability is an authentic existential interest. Gilson himself, as we said, when he is arguing against modern existentialism, makes this very point. In praising Thomas in this regard, he quotes Ecclesiastes III, 14: "I have learned that all the works which God hath made, continue forever."(55) The concern for permanence and temporality is an authentically existential concern.(56)
If we remember the passage in the Sophist(57) about the permanent war between the friends of the forms and the partisans of bodily being, we see, again, an interest in two dimensions of the problem of being, an interest which will eventually blossom in Aristotle's twofold division of being: being as divided by the categories, and being as divided by act and potency. The aim in the section is to show that there is as much difficulty in attempting to say what being is as what not-being is. [245E-246A] The Eleatic Stranger speaks of them as "those whose doctrines are less precise". As we read:
Str. And indeed there seems to be a battle like that of the gods and the giants going on among them, because of their disagreement about existence [peri tés ousias].[246A; tr. H.N. Fowler]
… define existence and body [soma kai ousian] … as identical… [246A-B]
Their opponents maintain
… forcibly that real existence [tén aléthinén ousian] consists of certain ideas [or forms: eidé] which are only conceived by the mind and have no body. But the bodies of their opponents, and that which is called by them truth, they break up into small fragments in their arguments, calling them, not existence, but a kind of generation combined with motion [genesin ant'ousias pheromenén]. [246B-C]
Because the giants need taming, the Stranger answers for them, proposing the following account of "the nature of being" [… toiond' einai to on]:
Str. I suggest that everything which possesses any power of any kind, either to produce a change in anything of any nature or to be affected even in the least degree by the slightest cause, though it be only on one occasion, has real existence [pan touto ontos einai]. For I set up as a definition which defines being [horon horizein ta onta], that it is nothing else than power [dunamis]. [247D-E]
Next we get the doctrine of the "friends of the ideas", the friends of the forms. It hinges on the distinction between generation [genesin] and being [ousian]. [248A] And we get this:
Str. … with the body, by means of perception, we participate [koinonein] in generation, and with the soul, by means of thought, we participate in real being [ontos ousian], which last is always unchanged and the same [aei kata tauta hosautos], whereas generation is different at different times. [248A]
I wish to stress that the interest is not merely in sameness, but that sameness means abiding always, i.e. permanence: it is a question of establishment in existence; and this is seen by the constant contrast with mere becoming or generation: that which sometimes is and sometimes is not. The Stranger raises a question about the participation or communion being discussed. Is it not to be defined in terms of the active and passive power already mentioned? This would seem to mean that the forms would have the power to act on the soul. However, the point is made that the friends of the forms do not accept this universal account of being already alluded to. They locate participation in the power of acting and being acted upon within the domain of generation. Neither power is connected with being [ousian]. [248D]
This is the problem set by the Stranger. The friends of the forms would exclude the whole of dunamis from true being. But it would seem that the soul knows and that being [ousia] is known. Are they going to exclude knowing and being known from the realm of action and passion? The Stranger suggests that ousia is moved in being known. He expresses a protest against the doctrine of the friends of the forms:
Str. But for heaven's sake, shall we let ourselves easily be persuaded that motion and life and soul and mind are really not present in absolute being [to pantelos onti],(58) that it neither lives nor thinks, but awful and holy, devoid of mind, is fixed and immovable? [248E-249A]
It is then decided that motion and the mover must be recognized as real beings [hos onta] [249B], since they cannot be expelled from the realm of the most perfect.
However, at this point, the Stranger doubles back to challenge the view that "all things are in flux and motion", and his argument is of great value as an exhibit of the concern for existence. He had reached the conclusion that without motion there is no mind. But he also has this:
… if we admit that all things are in flux and motion, we shall remove mind itself from the number of existing things [ek ton onton] by this theory also. [249B]
This is because without stasis no sameness of quality or nature or relations can come to be. And without these no mind could be or become. [249C]
It is concluded that the philosopher must require both motion and rest for an account of being. [249D] However, this raises the problem that, as they are exclusive, and both are, being itself seems to be distinguished from both. [250C]
My comment on this is to move to the contribution of Aristotle, which I here see as the wider notion of act, act as having degrees, and thus the conception of first act, second act, and motion or imperfect act.(59) This allows, for instance, a conception of mind which excludes motion, properly so called.(60) It seems to me that Aristotle, by presenting the division of being by act and potency, provides an advance which allows authentic modes of being, as contrasted with the Platonic distinction between being and becoming.(61)
In presenting act, Aristotle says:
Esti dé energeia to huparchein ta pragma mé houtos hosper legomen dunamei.(62)
The existentiality of this statement was seen by William of Moerbeke :
Est autem actus existere rem non ita sicut dicimus potentia.
Thomas, in fact, preferred using the verb "to be":
… actus est, quando res est, nec tamen ita est sicut quando est in potentia.(63)
Aristotle first presented potency in its connection with movement and change, and then came to the sort of act which is not a change, and the potency which corresponds to it.(64)
However, he had already commented on the etymology of the term "energeia"; Aristotle himself tells us:
The word "act" which we connect with "complete reality" [entelecheian], has, in the main, been extended from movement to other things; for act in the strict sense is thought to be identical with movement. And so people do not assign movement to non-existent things [tois mé ousin], though they do assign some other predicates. E.g. they say that non-existent things [ta mé onta] are objects of thought and desire, but not that they are moved; and this because non-beings actually will be actually. For of non-existent things some exist potentially; but they do not exist [esti], because they do not exist in complete reality [ouk entelecheia esti].(65)
In Thomas's paraphrase we read:
 … he shows us what being in act [esse in actu] is; and he says that this word "act", which is put forward to signify completeness [endelechiam] and perfection, viz. form, and other such items, such as are any operations, comes [veniunt], as regards the origin of the word, most of all from movements. For since names are signs of intelligible conceptions, we impose names firstly on those items which we firstly know intellectually, even though they are posterior in the order of nature. But among other acts, movement, which is sensibly seen by us, is maximally known and apparent to us. And so on it the name "act" was first imposed, and from movement it has been derived to others.
 And for that reason being in movement [moveri] is not attributed to non-existents [non existentibus], even though some other predicates are attributed to non-existents. For we say that non-beings [non entia] are intelligible or opinable, or even are desirable, but we do not say that they are moved: for, since "being in movement" signifies being actually [esse actu], it would follow that non-beings were actually; which is obviously false. For though some non-beings are in potency, nevertheless they are for this reason not said to "be", because they are not in act [non sunt in actu].(66)
I stress this consideration because it helps indicate the extent to which the Aristotelian interest in movement constitutes a properly existential interest. He has managed to improve on Plato precisely by bringing into the account of being as such the truth which was involved in the position of the earth-born giants, as presented by the Eleatic Stranger. And he has done this largely by seeing the analogical unity of the notion of "act".(67)
With the Aristotelian doctrine of act, we have a definitely existential metaphysics. It can take secondary causality seriously as authentic giving of being. As including the doctrine of potency, it can take corruption seriously as ceasing to be. Yet it leaves room for causal hierarchy and a causality of being as being.
I would say that the distinction between esse and essence in later philosophy, St. Thomas's in particular, is an appreciation of the implications of causal hierarchy for the doctrine of the primacy of being in act.(68)
My general line is that Plato posed the kinds of question which required Aristotle's doctrine of being as divided by the categories and being as divided by act and potency. Once this latter synthesis was achieved, we had a doctrine of modes of existence which found its proper expression in the distinction between esse and essence.(69)
Thomas shows this in SS. The second area of agreement between Plato and Aristotle discussed by Thomas is what he calls "the condition of the natures" [...ad conditionem naturae ipsarum...] of the substances under discussion. What Thomas means by their "condition" is to be gathered from the context. Whereas "modus existendi", the first area of agreement, concerned the question of origin, i.e. having one's being "measured" by a relationship to an efficient cause,(70) "conditio naturae" looks within the substance itself, probes its intrinsic ontological density, if one may so put it. Both Plato and Aristotle, Thomas tells us, held that all such substances are altogether immune from matter. Nevertheless, they are not altogether immune from the composition of potency and act. For the case of Plato, Thomas points out that when something is received in a being as a participated feature, it has the role of act vis-à-vis the participating substance. Hence, in the doctrine of Plato, all the substances other than the supreme are potency/act composites. And it is necessary to say the same thing according to the doctrine of Aristotle. Aristotle holds that the intelligible aspects expressed by the terms "true" and "good" are to be attributed to what he calls "act": hence, the primary true and the primary good must be pure act, and whatever fall short of this must have an admixture of potency.(71)
This passage is interesting in that we clearly have to do with the intrinsic ontology of separate substance. Does Thomas attribute to Plato and Aristotle a doctrine of composition out of "essence and existence"? At this point in the text, he uses a more general vocabulary. However, what we should especially note is the way Thomas exploits the content of discussion in Aristotle's Metaphysics 9, chapters 9 and 10,(72) tying it to the views of books 2 and 12: I mean the order of secondary separate substances of book 12.(73)
My general contention, then, is that Greek philosophers, i.e. the pre-Socratic cosmologists and Plato and Aristotle, were raising existential questions. Thomas Aquinas appreciated this, and saw in Plato and especially in Aristotle a briefly expressed doctrine of eternal creation. Other interpreters of the Greeks, whether in the 13th or in the 20th century, have failed to appreciate this, one big reason being that they could not altogether purge their conception of creation of the aspect of "coming into being". As Thomas often says, even the word "fieri", i.e. to become, or to be made, is rather unsuitable when speaking of being created.(74)
We should take seriously Thomas's reference to Aristotle's God as pure act. This is related to the intelligibility of hierarchy, and suggests that room has been found for a potency even in the separate substances. In this connection, we should take seriously Thomas's on lambda. This notion of act is precisely that of esse. Gilson made Aristotle's God the pure act of "thought" rather than of being, but that is nonsense. It is being as being which is divided by act and potency. - If our interest is really in the importance of the act of being in Thomas's metaphysics, then I would say that Aristotle's division of being as being by act and potency is the key. Of course, inasmuch as one is not dealing with causal hierarchy, there is no room for seeing a real distinction between form and esse; but once efficient causality is introduced, with the immediate implication of efficient causal hierarchy, then a distinction must be made.
I should say that we only see the distinction between form and esse when we consider a thing precisely as caused by another. Otherwise, the vision of form and the vision of esse is one and the same. The danger is that we will conceive of form as evidently distinct from esse. This has the effect of moving form into a zone of quasi-mathematical abstraction, so that it is no longer even the principle of esse.(75) One sees this in the work of Gilson. Thus, in a paper published in 1964, on virtus essendi, he understood the virtus essendi in things to be esse itself. He could not see that Thomas was speaking about the form as distinct from and principle of the act of being. He had taken as isolated one from the other the order of essence and the order of being in act.
As Thomas says in at least one place, all esse is considered through form. This is to say that form is the visibility of esse. It is only inasmuch as form is merely "such form" that it is distinct from esse, and merely potential relative to esse. The divine form is most truly form.
I will finish with a consideration of the question: what is the metaphysical appearance of a created universe? While Plato has shortcomings re the being of sensible things and their generation and corruption, he can still have a doctrine of creation. Nothing might truly come to be and cease to be, and yet as a whole, all truly depend on a first principle through and through. How does Thomas present creation in Plato? Certainly, the doctrine of creation is more directly identifiable in what he says about Aristotle. However, he says that Plato and Aristotle agree on the mode of existing of the separate substances lower than the first. We read:
… Plato posited that all lower immaterial substances are one and good through participation in the first which is one and good just in itself; but everything participating in something receives what it participates from that from which it participates, and in that regard that from which it participates is its cause: as air has light participated from the sun, which is the cause of its illumination. Thus, therefore, according to Plato, the supreme God is the cause for all immaterial substances that each of them both is one and is good. And Aristotle also held this, because, as he himself says, it is necessary that that which is maximally a being and maximally true be the cause of being and truth for all others. [SS, c. 3 (Leonine lines 8-21)]
Anyone who has read SS chapters 9-11 knows that this issue of mode of existing is precisely the question of creation. Those three chapters are about three ways of deviating from the truth about the mode of existing of the spiritual substances, a deviation from the truth [c. 9, line 7] which is also a deviation from the doctrine of Plato and Aristotle [c. 9, line 103]. The errors all involve a denial that they have their origin in the first and highest author. [c. 9, lines 8-9]
What does createdness look like?(76) Let us recall the general plan for a way to God, as presented in the Summa theologiae. We are to reason from the existence of an effect, better known to us than its proper cause, to the existence of that proper cause.(77) What is the effect, seen as an effect, in the Fourth Way, and to what "proper" cause does it lead us? The Fourth Way leads to a maximal being, which is cause of being for ALL beings. The universality of this effect is to be noted. The cause in question is viewed as the cause of a universal effect. Thomas does not content himself with saying that there is a first being which is the cause of being for all other beings. That, I would say would not be wrong, but it would be mild and apt to mislead. Rather, he "goes out of his way", one might say, to establish that the cause of which he is speaking is such as to dominate an entire field in what I would call a "formal" way. After reasoning to the actual existence of the maximal being, by what is clearly an efficient/exemplar causal route,(78)
he adds that such a maximal item is the cause of all the things which belong to the same order. He then comes to God named precisely as he wished to arrive at God in this Fourth Way, viz. as "cause of being for all beings". The fact that the way sees the hierarchy as both of goodness and being helps us see why Thomas treats Plato and Aristotle together.
What is remarkable about the Fourth Way is its capacity to combine the formal universality of the aspect of things taken under consideration, with the manifestation of the effect status of that aspect. It differs from the Third Way in this, that in the latter the features considered were differences of being, i.e. the possible and the necessary. The effect character was first seen in the possible, and was then extended to the necessary almost merely by hypothesis.(79) In the Fourth Way, we have moved beyond such "differences" to consider the form itself in its universality - we consider goodness, truth, nobility or perfection, and being. They are what Thomas calls, on at least one occasion, "universal form" [forma universalis].(80) They are maximally communicable: they "get into everything", we might say. Their universality is not merely "extensive" but "intensive". However, they are common "according to priority and posteriority". They present themselves in gradation. This is their typical formal appearance.(81)
It is this gradational formal unity, which, as available to our observation, remains indefinite in its ascent towards the more and more perfect, which constitutes the properly metaphysical field of inquiry. On the one hand, it is a "nature with its proper differences" (the possible and the necessary, or, perhaps better, potency and act). On the other hand, it is an effect which elicits the question concerning its cause (i.e. it is a gradation of indefinite extent towards the top).
We should keep in mind that in his sermons on the Apostles' Creed given at Naples in Lent, 1273, as regards the existence of God, Thomas relies on purpose vs. chance, considerations related most obviously to the Fifth Way; this is a markedly "providential" line of thinking: God as cause of directed movement. On the other hand, when the createdness of reality is to be addressed, he immediately uses the image of the house in winter, with a little warmth felt at the front door, greater warmth as one goes inside, even greater warmth as one advances to the next room - with the judgment that a furnace radiating all this heat is present somewhere within. The listener is urged to consider observable reality as graded. In that way, the createdness of reality will be seen.(82) Reflection on the idea of a "cause of being as being" should lead us to see why the Fourth Way takes the form it does. Metaphysics has for its proper field of study being as being. This is a unified field for which one can point to a proper cause.(83)
Addendum concerning the Authenticity of Metaphysics, book alpha elatton:
Since so much of Thomas's interpretation of Aristotle's metaphysics depends on his reading of Metaphysics, book Alpha elatton, something should be said about this treatise. Sir David Ross, in Aristotle, Metaphysics (text with introduction and commentary by W.D. Ross), Oxford, 1924 (corrections, 1953): Oxford University Press, vol. I, p. xxiv, points out that it interrupts the connexion between books A and B, that it refers to no other book and is referred to by none. The "title" suggests that it is probably the latest addition to the corpus of the Metaphysics, added after the other books had already been numbered. One of the oldest manuscripts (E) [Parisinus gr. 1853: 10th century] has a scholion saying that most scholars attribute the book to Pasicles of Rhodes, a pupil of Aristotle and a nephew of Eudemus. Ross reports that Alexander, Asclepius, and Syrianus think it is by Aristotle. Alexander has doubts about it being in its proper place, and thinks it is an introduction to theoretical philosophy in general. Ross judges that "they are right in thinking both the thought and the language thoroughly Aristotelian." [p. xxv] However, he agrees with Jaeger that the lack of connection between the three chapters indicates that we have in it Pasicles somewhat fragmentary notes of a discourse by Aristotle. Ross takes the conclusion as indicating it was meant for an introduction to physics, and so it was a mistake to place it within the metaphysical group of materials. - At p. 213 in his Commentary, Ross repeats his views:
Alexander thinks that a is the work of Aristotle, and the contents and style are quite in keeping with this view. The tradition about Pasicles is likely to have some basis, and the truth may be that the fragment was recovered from his notes of Aristotle's lectures. [p. 213](84)
A more recent study and judgment can be found in Bertrand Dumoulin, Analyse génétique de la Métaphysique d'Aristote, Montréal and Paris, 1986: Bellarmin and Les Belles Lettres, pp. 75-83. The account is valuable as indicating the variety of opinion among recent scholars. It also indicates some places where passages in other works of Aristotle (especially fragments) harmonize with the treatise, other places where there is disharmony in Dumoulin's opinion. Most important for our discussion is his treatment of 2.1 (993b28-31). We read:
« De là vient que les principes des êtres éternels sont nécessairement les plus vrais de tous… il n'y a pas de cause de leur être; au contraire ce sont eux qui sont la cause de l'être des autres choses. » Les « êtres éternels » doivent ici désigner les astres (cf. E 1, 1026a16-18) et leurs « principes » doivent êtres les dieux [he notes here the agreement of Decarie and Berti]. Mais comment entendre tois husterois aition tou einai? Si l'on interprète le passage en question à travers les textes de la maturité (comme Du Ciel 1.9 [279a28-30]; Metaph. Lambda 1-8) Dieu ne peut être cause que du devenir des choses, et non pas, par exemple, de l'existence des astres. [A note here tells us that thus E. Berti interprets a as making God merely the cause of the determinate being and not of the esse simpliciter.] Au contraire le principe de sunanairesis impliqué en Protr. Fr. 5 Ross (B 33 et 35 Düring) semble requérir une dérivation de l'existence des choses qui dépendent d'un principe suprême; les fr. 13 et 17 Ross du De philos. vont dans le même sens; déjà chez Platon le Bien est cause de la vérité et de l'être des choses (Rép. IX 585b-d; VI 509b); enfin, dans la Métaph. de Théophraste, « est divin le Principe de toutes choses, par lequel à la fois elles existent et se conservent » (4b16-17). Il nous semble que les mots doivent être pris prout sonant et que la divinité est ici posée comme cause de l'existence des êtres inférieurs. [p. 78]
Dumoulin adds a note [#18] to the effect that the final paragraph of a 1 has an important place for St. Thomas, as the basis of 4th way. He notes that Thomas depends on it, and secondarily on E 1 to maintain that God is cause of the existence, and not merely of the motion, of the heavens. (He refers to Spiazzi #295 and 1164.) He tells us that Berti counts 44 references in Thomas to this passage. Dumoulin thinks Thomas was in error in extending its doctrine to the whole of the Metaphysics.
At the end of his discussion of the whole treatise, pp. 82-83, Dumoulin judges as follows:
…ce livre apparaît comme l'œuvre d'un membre du Lycée qui a puisé ça et là dans l'œuvre d'Aristote et a développé des thèmes aristotéliciens selon son inspiration personnelle et les idées courantes dans l'école après la mort d'Aristote. [pp. 82-83]
Dumoulin underlines the resemblance with certain doctrines of Theophrastus. Thus, where G. Reale sees evidence for Aristotle as author of a in the Metaphysics of Theophrastus, Dumoulin [p. 82] argues that one could see Theophrastus as source for a.
Among the opponents of the authenticity of a mentioned by Dumoulin, one should note especially G. Vuillemin-Diem [mentioned in n. 27, p. 81], concerning the attribution to Pasicles. It is claimed that the 10th century scholion in ms. E could be related either to the end of book A or the beginning of a; that a 14th century scholion of ms. E attributes a explicitly to Pasicles; and that the origin of the first scholion is Asclepius, in a passage which intends book A, which Asclepius says some people attributes to Pasicles.
I was happy to see that Dumoulin reads a 1 as making the highest causes the cause of being of the heavens, just as Thomas does. But for the bigger picture, Dumoulin is a practitioner of "genetic analysis", as his title indicates. The bases of his judgments about what Aristotle would say and would not say are very delicate. If he were right, I would have to say that Thomas's source is Theophrastus or one of his pupils. However, it is a very daring judgment he proposes, I would say.
I was also happy to see that Leon Elders, Revue Thomiste 90 (1990), in the Bulletin on « Aristote: sa pensée, ses textes, son influence », pp. 147-161, in his revue of Dumoulin at pp. 152-153, speaks of "conclusions peu sûres" (p. 152). And we read:
Le livre A Elatton est déclaré non authentique (contrairement au consensus grandissant des aristotélisants modernes). (p. 152).
1. Étienne Gilson, speaking of Descartes and the Middle Ages, rejects the word "source", since he sees Descartes as destroying the doctrines he exploits:
Une grande quantité de notions et de conclusions étaient passées de leurs doctrines dans celle de Descartes, mais le mot (99) "source" décrit mal la situation. Rien ne s'était vraiment écoulé de la théologie scolastique dans la philosophie cartésienne. Plutôt que d'y remonter comme à une source, Descartes avait exploité la scolastique comme une carrière. [Cf. Le philosophe et la théologie, Paris, 1960: Fayard, pp. 98-99.]
2. Cf. ST 1.117.1: whether one human being can teach another? This is Thomas's portrait of the learner and the teacher, and just how one person can help another in matters intellectual.
3. One might here remember Jacques Maritain on philosophical cooperation, in Theonas.
4. Cf. ST 1.44.2:
… antiqui philosophi paulatim et quasi pedetentim intraverunt in cognitionem veritatis…
5. Such an imperfect act is reducible to the category to which the perfect act belongs, and thus we have to do with inchoate formal causality: cf. CP 3.5 (ed. Maggiolo, 324 ).
6. Cf. ST 1.9.1 [46b11-14].
7. Cf. ST 1.105.3, and our work, in a series of papers, on the notion of being as motor for the whole of our intellectual life: "St. Thomas and the Ground of Metaphysics", in Philosophical Knowledge, edited by John B. Brough, Daniel O. Dahlstrom, and Henry B. Veatch [Proceedings of the American Catholic Philosophical Association, vol. 54], Washington, DC, 1980: ACPA, 144-154; "St. Thomas, Physics, and the Principle of Metaphysics", in The Thomist 61 (1997), pp. 549-566; "Jacques Maritain, St. Thomas, and the Birth of Metaphysics", Études Maritainiennes /Maritain Studies 13 (1997), pp. 3-18.
8. Plato, Sophist, 246A-247E.
9. Thomas calls Aristotle "breviloquus", a man of few words; cf. In De caelo, 2.17 (457 ).
10. Thomas, In De caelo 1.9 [ed. Marietti, 97 ] concerning Aristotle, 1.5 (271b1ff.).
11. Consider, for example, the relation of his doctrine of the incorruptibility of the human soul to that of Avicenna, as I present it in my paper: "Saint Thomas, Form, and Incorruptibility", in Jean-Louis Allard (ed.), Être et Savoir (Philosophica 37), Ottawa, 1989: Les Presses de l'Université d'Ottawa, 77-90.
12. One thinks especially of CM 4.2 (#556 and #558), concerning Aristotle's doctrine (Metaph. 4.2 [1003b32-33]) that "ens" is predicated per se of substance.
13. One thinks especially of CP 8.2 (Maggiolo ed., 973 -975 , concerning Aristotle, Phys. 8.1 (251a8-17); Averroes rejects creation as a mode of production, against Aristotle.
14. On this, see my paper: "St. Albert, Creation, and the Philosophers", Laval théologique et philosophique 40 (1984), 295-307.
15. The key text for this is De substantiis separatis [henceforth "SS"], produced in the last years of Thomas's career (James Weisheipl, O.P., Friar Thomas d'Aquino, Garden City, NY, 1974: Doubleday, p. 388, gives "Paris or Naples, 1271-1273").
16. Cf. my paper: "Thomas Aquinas, Creation, and Two Historians", Laval théologique et philosophique 50 (1994), pp. 363-387.
17. Joseph Owens, The Doctrine of Being in the Aristotelian Metaphysics, Toronto, 1963 [second revised edition]: Pontifical Institute of Mediaeval Studies, p. 453, n. 63, quotes David Ross: "If Metaphysics lambda tells us anything, it tells us that God's thought is a thinking on thought and on nothing else, and that God moves the world only hos orekton." - I notice that Roopen Majithia, in "The Relation of Divine Thinking to Human Thought in Aristotle", American Catholic Philosophical Quarterly 73 (1999), pp. 377-406, at pp. 405-406, n. 66, makes Aristotle's God an efficient cause, explicitly opposing Sir David Ross. Majithia's paper notes three different interpretations of Aristotle's self-thinking thought as regards the question of God's knowledge of other things: p. 378.
18. Cf. ST 1.44.1. Thus, in CM 12.8 (2550), the celestial body receives incorruptibile esse from the first, which means that the celestial body must have in itself no "potentia ad non esse". At CM 12.7 (2534), the heavens are said to be dependent on the first principle, which is the first mover as an end, for the perpetuity of their substance as well as their motion. This relates to CM 2.2 (295-296). Cf. also CM 6.1 (1164).
19. Cf. my paper: "St. Thomas, Aristotle, and Creation", in Dionysius 15 (1991), 81-90. Cf. Metaph. 12.10 (1075b8-10): the position of Aristotle is that the supreme intellect is both agent and goal: the medical art is somehow the same as health. Thus, he says that Anaxagoras could save his position by taking the same line as he, Aristotle, took. - There is a recent paper by Sarah Broadie, which I have seen in French translation in Revue philosophique de France et de l'étranger 183 (1993), pp. 375-411, and entitled « Que fait le premier moteur d'Aristote? (Sur la théologie du livre Lambda de la 'Métaphysique') »; in it, it is strongly argued that the prime mover must be an efficient cause and not only a final cause; cf. p. 379, n. 4. The efficiency she has in mind is production of movement. - Of course, even if Aristotle had not envisaged a final cause that was also efficient cause, one could still recognize that Thomas agrees with him as to the doctrine that only the final cause is an unmoved mover, but adds that nothing prevents the final cause from being also an efficient cause: indeed, this must be so in the case of the first final cause! Thomas himself makes this argument, viz. that only God can be the primary agent acting on account of himself as end, in SCG 1.72 (ed. Pera, #625; tr. Pegis, para. 9).
20. Etienne Gilson revised his view of esse in Thomas as the years went by. For example, in Being and Some Philosophers [henceforth "BSP"], Toronto, 1952 [2nd ed.]: Pontifical Institute of Mediaeval Studies, p. 172, it is conceived of an internal efficient cause. In "Virtus essendi", Mediaeval Studies 26 (1964), pp. 1-11, at p. 5, we are warned against this conception of the role of esse, and it is presented as a formal cause, but one to be very carefully and sharply distinguished from the form proper to the thing. However, in this latter paper Gilson strangely conceives of the esse of the thing as the very "virtus essendi" which Thomas speaks of finding in Aristotle's De caelo. He conceives it as in no way subject to the more and the less. Had he consulted CP 8.21 (1153), he would have seen that the "virtus essendi" of which Thomas was speaking was the potency of the form relative to the esse. Gilson's problem with esse stems, it seems to me, from his de-existential conception of form and essence. He builds a wall between the order of essence and the order of being. - For criticism of Gilson concerning esse, see my paper: "Étienne Gilson and the Actus essendi", Maritain Studies / Études Maritainnienes 15 (1999), pp. 70-96. For criticism of Joseph Owens regarding esse, see my papers : "St. Thomas, Joseph Owens, and Existence", New Scholasticism 56 (1982), 399-441, and "Saint Thomas, Metaphysical Procedure, and the Formal Cause", in The New Scholasticism 63 (1989), 173-182.
21. In fact, Albert has a different conception of creation than Thomas has. Albert does not think that creation of the total composite, matter as well as form, is compatible with a doctrine of the eternity of the world. Cf. Albert, Super Dionysium De divinis nominibus, ed. Paul Simon, in Opera Omnia, t. 37/1, Monasterii Westfallorum, 1972: Aschendorff. Albert says:
… God indeed is a perfect agent and can bring the entire thing into being [educere totam rem in esse], but these are not mutually compatible, that something be brought into being as regards its entire substance, i.e. as to both matter and form, and be eternally, because such creation necessarily posits a beginning of duration, though the creation of which Avicenna speaks, which is only of forms, can be understood as from eternity… [p. 118, lines 75-83]
But the more interesting discussion in this line is in ch. 2, sec. 44-45, pp. 72-74. Albert is commenting on Dionysius's presentation of the procession of creatures from the Triune God. [PG 3, 641D] Albert first presents Plato and Avicenna, with the doctrine of the creation of forms, matter having to be given. However, in this view God could never be the cause of matter. Accordingly, Albert prefers Aristotle, whose doctrine is that forms are present in matter in potency. One can add to this the Christian doctrine of creation, since it is compatible with God having an idea of matter. Aristotle without a doctrine of creation is more compatible with the Christian Faith than Plato and Avicenna who have creation of form but a matter which could never be a creature.
The commentaries of Albert on Dionysius have come down to us in what is very likely the autograph of student Thomas Aquinas himself: cf. Paul Simon's Prolegomena, pp. vi-viii, in the above-cited tome.
For Thomas's own view, right from his literary outset, cf. Sent., 2.1, expositio textus (ed. P. Mandonnet, Paris, 1929: Lethielleux, p. 43):
… Aristotle did not err by positing several principles: because he held that the being of all [esse omnium] depends on the first principle alone; and so it remains that there is one first principle; he did err in positing the eternity of the world.
… according to him [Aristotle], … form and matter… are produced by that first principle.
22. A reading of the letters exchanged between Gilson and Jacques Maritain in the years 1931-1932 makes this clear. It also reveals how delicate was the issue of the interpretation of Aristotle. Maritain's position is closer to what I am saying, but does not do full justice either to Thomas's view of Aristotle or (as I believe) to the true Aristotle. Cf. Étienne Gilson / Jacques Maritain, Correspondance 1923-1971, éditée et commentée par Géry Prouvost, Paris, 1991 : Vrin [henceforth " Prouvost"]: ch. II (1931-1932), L'amitié nouée. Philosophie chrétienne (pp. 41-99). Here I will note only letter #17, Maritain to Gilson, May 5, 1931, where Maritain is attempting to get Gilson to be more precise. We read :
Maintenant il me semble que pour que votre thèse soit formulée d'une manière inattaquable, une expression comme « Aristote n'est pas allé jusqu'à l'Être » reste trop générale; il faudrait arriver à la formule vraiment technique et explicite où tout ce développement historique aboutit : Aristote n'est pas allé jusqu'à la doctrine de l'essence et de l'existence réellement identiques en Dieu et réellement distinctes en tout le reste. C'est la vérité fondamentale de saint Thomas, et à vrai dire sans cette doctrine toute la théorie de l'Ipsum Esse subsistens est métaphysiquement dévalorisée. [pp. 64-65]
Maritain was not aware of, and so does not deal with the problem, that Thomas himself attributes the doctrine of God as the simple act of being, all else as a composite of (at least) form and act of being, to Aristotle and even to Plato; he does so in SS c. 3 (Leonine lines 22-39).
23. Cf. Gilson, "Compagnons de route", in Étienne Gilson, Philosophe de la Chrétienté, Paris, 1949: Cerf, pp. 275-295. Gilson notes that Bergson took years to realize that religion was at the heart of all that he had been doing. So also, says Gilson, a lesser man such as himself might not surprisingly have taken years to see what he had been working towards. He says:
Towards the end of a long life, Bergson was astonished not to have seen, right from his first works, that religion was already immanent in them. It is no less surprising, for a lesser man than [Bergson], that, haunted from the beginning by the mystery of existence, he could first have attached himself to St. Thomas Aquinas, as though by virtue of an obscure elective affinity, have read him, taught and presented him many times in the course of so many years, have spoken even in following him the words which he spoke, without having understood until almost too late [tardivement], in writing God and Philosophy, that the answer coincided here with the question itself. One does not explain esse, it is what explains all the rest, including duration and creative evolution itself. [pp. 291-292]
Interestingly, in 1949 when he wrote this, Gilson singled out Cajetan as one who had already shared his insight into the importance of esse. [p. 294] The book, God and Philosophy, New Haven, 1941: Yale University Press, finished by Gilson in Toronto about February of 1940, and delivered as lectures at Indiana University in March, before his return to France in April (where he spent the war); cf. L. K. Shook, Etienne Gilson, Toronto, 1984: Pontifical Institute of Mediaeval Studies, pp. 240-242.
24. God and Philosophy, pp. 33-34. My italics. He goes on to make the rather bald statement, still presenting Aristotle, that:
Truly wise men do not play at being gods; they rather aim to achieve the practical wisdom of moral and political life. God is in his heaven; it is up to men to take care of the world. (34)
It is impossible to recognize in this Aristotle's wise man: cf. EN 10.7-8, especially 1179a20-33.
One of the odd features of Gilson's first chapter, on "God and Greek Philosophy", is that he makes a sharp distinction between person and thing, and sees the gods as religious principles which are persons, but the philosophical principles are things. I would have thought that, as soon as one comes to the Nous of Anaxagoras, where the first principle is intellectual, one has what should be called a "personal being". Its personal life may be a closed door to us, but that does not mean it is merely a thing. Thus, at p.37, he tells us that:
What men cannot possibly bring themselves to do is to worship a thing.
25. Cf. my paper, "St. Thomas and Creation: Does God Create 'Reality'?", in Science et Esprit 51 (1999), pp. 5-25.
26. Cf. BSP, p. 40.
27. And the reading of Anton Pegis as well; cf. the previously mentioned "Two Historians" paper.
28. Cf. Prouvost, p. 58: letter 14, Gilson to Maritain, April 20, 1931:
Ce qui me frappe et m'avait depuis longtemps frappé - c'est même ce qui m'a fait fouiller de nouveau les textes - c'est que jamais saint Thomas n'a appliqué à la doctrine d'Aristote le mot creatio. Ç'eût été si simple! Je me suis dit : s'il ne l'emploie jamais, c'est qu'il l'évite. Pourquoi? Je crois que nous avons la réponse dans la Somme.
Gilson's reference to the ST has to do with his interpretation (his misinterpretation) of 1.44.2 as denying a doctrine of causality of being as being to Aristotle. The answer to his question, I would say, is found in ST 1.45.3.ad 3: the word "creatio" signifies the relation of the creature to the creator, along with newness or beginning [cum quadam novitate seu incoeptione]. Obviously, so taken, the word does not fit the doctrine of Aristotle. Thomas notes, in 1.46.2.ad 2, the philosophers' doctrine that the world is made from nothing by God, not "after nothing, as we understand by the word "creation"; and he notes, as a point of interest, that one philosopher, Avicenna, actually uses the vocabulary of "creation" for the making from nothing of an eternal world. In SS, after carefully explaining the higher mode of production which trancends all change, and by which ipsum esse communiter sumptum is precisely what is attributed to things, and tracing this doctrine to Plato and Aristotle [c. 9, Leonine lines 102-136], Thomas goes on, in c. 10, Leonine line 92, to call "the mode of production which is without change" "creation"; and he repeats this at lines 122-125:
… nullum agens post primum totam rem in esse producit quasi producens ens simpliciter et per se et non per accidens - quod est creare, ut dictum est -.
Thus, even on this point of vocabulary, I would say that Gilson is not quite right.
29. Cf. SS, c. 3 (Leonine lines 22-39).
30. Cf. e.g. BSP, p. 155 and p. 159.
31. We might note the evident existential interest of Aristotle at this point, 251a18.
32. On createdness as the point of departure of the [ST 1.2.3] 4th way, cf. my paper:" St. Thomas, the Fourth Way, and Creation", The Thomist 59 (1995), pp. 371-378.
33. Thomas in his commentary on De caelo (dated by Weisheipl 1272-1273) uses the Moerbeke translation from the Greek, and the Latin term "virtus" does not occur. Cf. the commentary of Albert the Great. This is to be found in Opera omnia t. 5/1, Monasterii Westfallorum, 1971: Aschendorff, edited by Paul Hossfeld. Albert, writing at Cologne in the early 1250s, uses the translation made from the Arabic by Gerard of Cremona in the late 12th century. However, he also makes use of the translation from the Arabic by Michael Scotus of about 1230, a translation associated with the commentary of Averroes. The basic text introduced into the paraphrase is that of Gerard. I am interested in the occurrence of the word "virtus". Can Aristotle be seen as really speaking of a virtus which belongs to the thing which always is? I am looking at Albert, lib. 1, tract. 4, cap. 7 [ed. cit., pp. 91-92]. This is a paraphrase of Aristotle, 281b20-282a1, approx. The text of Aristotle, as translated by Gerard, has:
Generatum autem est illud quod est in primis non existens, deinde est post non-existentiam, et non est rei sempiterni esse virtus, ut sit non existens neque in tempore finito neque in tempore infinito. Non enim est possibile, ut rei uni sit virtus, ut sit semper existens et ut sit semper non existens, neque est possibile negativa, ut sit vera, sicut dicitur, quia non est possibile res una, ut sit existens semper et ut sit non existens semper. [lines 87-90, p. 92] [my caps]
Albert, in his paraphrase, has:
Rei autem sempiterni esse secundum omne tempus est opposita his definitio, et ideo etiam convenit eidem virtus opposita, et virtus generati et virtus corruptibilis removetur ab ipsa re sempiterna. Et ideo tali rei sempiternae non est virtus, ut sit aliquando non existens secundum tempus finitum, neque est ei virtus, ut sit simpliciter non existens secundum tempus infinitum, sed puram habet virtutem ad semper-existendum secundum omne tempus infinitum. Istae igitur virtutes uni rei non conveniunt, quod videlicet res una sit semper existens et ut sit semper non existens vel etiam non semper existens. [lines 64-75, p. 92]
This helps to see where Thomas reads what he reads.
Sometimes Thomas calls this power to be "active" (SCG 1.20 [para. 174]) and sometimes he denies this and calls it "receptive" (CM 12.8 (2550): "non …virtus activa sui esse, sed solum susceptiva"; at In De caelo 1.6 (61 ), he says it is not passive (that is the potency of matter with respect to being) but rather "pertains to the potency of form".
34. Cf. Gilson, BSP, pp. 166-167.
35. In the 6th edition of Le thomisme, wherein Gilson famously rejects the interpretation he gave of Thomas's Five Ways in the 5th edition of the same work, he says that Thomas's own notion of esse is not at work in the Five Ways: to say otherwise would involve attributing that notion to Aristotle, something no one dreams of doing. I would say that someone, namely Thomas Aquinas, does attribute that notion to Aristotle. Cf. Le thomisme, 6th ed., Paris, 1979 [original 6th ed. in 1965]: Vrin, p. 97, n. 85.
36. In fairness to Gilson, cf. Prouvost, p. 59, Gilson to Maritain: letter #14, April 21, 1931, on the importance of the Greek philosophical heritage:
… s'il y a une philosophie chrétienne, c'est parce qu'il y a une philosophie grecque. Du moins, j'en suis convaincu. Sans la philosophie grecque, l'Évangile n'aurait pas plus engendré de philosophie chez les Chrétiens que la Bible n'en avait engendré chez les Juifs. La philosophie chrétienne c'est bien, selon vos expressions, la « philosophie » dans son état chrétien. Je reprendrai tout cela dans mes conclusions, lorsque j'aurai derrière moi l'ensemble de mon enquête.
Gilson is here speaking to Maritain about his preparation of his Gifford Lectures, L'Esprit de la philosophie médiévale.
37. Thus, in Metaphysics 4.1, Aristotle proposes a science of being as being, in contrast to sciences which have as their field of study only some part of being. It is a science that seeks the highest causes and principles, and these must be causes of some nature. As Thomas paraphrases:
… Every principle is the essential principle and cause of some nature. But we seek the first principles and the highest causes… therefore, they are the essential cause of some nature. But of no other nature than that of being. [CM 4.1 (533), on Aristotle at 1003a26-32. Italics mine.]
In ST 1.45.5.ad 1 (288b35-38), Thomas qualifies his use of the term "natura" for the field of reality as falling under the cause of being as such:
… sicut hic homo participat humanam naturam, ita quodcumque ens creatum participat, ut ita dixerim, naturam essendi; quia solus Deus est suum esse…
[… as this man participates human nature, so also each created being whatsoever participates, if I may so speak, the nature of being, because God alone is his own being…]
As presented by Thomas, the field of metaphysics has a per se unity. Nevertheless he insists that its unity is one of "analogy" or imitation. In the ST 1 the most important text is perhaps 1.4.3, on the way in which creatures can be said to be "like" God.
38. SCG 3.72 (#2481).
39. We have the same doctrine in ST 1.22.4: does providence impose necessity on the things cared for? In fact, what we see here is an answer to a very common error, that a universal and omnipotent providence necessarily results in everything happening of necessity. We get again an appeal to the doctrine of the final cause of creation:
It pertains to providence to order things towards an end. After the divine goodness, which is the end separated from things, the principal good existing within things themselves is the perfection of the universe; which [perfection] would not be [non esset], if not all the grades of being were found in things [si non omnes gradus essendi invenirentur in rebus]. And so for some effects God prepared necessary causes, so that they might occur necessarily; but for some contingent causes, that they might occur contingently in accordance with the condition of the proximate causes. [1.22.2 (157a49-b11)]
Once more, we have the appeal to what constitute the grades of being. And we should remember the added point in the ad 3:
… the necessary and the contingent properly accompany being as such [consequuntur ens inquantum huiusmodi]. Hence, the mode of contingency and necessity falls under the provision of God, who is the universal provider of all being [totius entis], but not under the provision of any [merely] particular providers.
Here we come to the ultimate metaphysics of the situation. God is the cause of being as being, and these are proper differences of being as a nature.
40. Cf. Aristotle, Metaph. 6.1 (1026a19).
41. Ibid. 6.2 (in its entirety).
42. CM 6.3 (1218-1220).
43. The CM 6 treatment is Thomas's most elaborate presentation of this point, but he does teach it in many other places. Thus, in his Commentary on Aristotle's Perihermeneias, he raises the question of providence and necessity. After dealing with it from the viewpoint of the problem of certain knowledge of future contingents, he takes up the problem of the divine willing of events. There is a parallelism of conceptions which we might note. In order to convey the stance of the divine observer relative to the flow of history, he had said:
… God is altogether outside the order of time, as established in the fortress of eternity, which is altogether at once, beneath which the entire course of time is laid out… and so in one look he sees all things that are done in the entire course of time, each one existing as it is in itself…
And so, coming to the difference of the divine will from human wills, he says:
… the divine will is to be understood as standing outside the order of beings [ut extra ordinem entium existens], as a cause pouring forth being in its entirety [totum ens] and all its differences. Now, the possible and the necessary are differences of being [differentie entis], and so it is from the divine will itself that necessity and contingency in things have their origin, and the distinction of both in virtue of the proximate causes: [thus] for the effects that he willed to be necessary he established necessary causes, and for the effects that he willed to be contingently he ordered causes acting contingently, i.e. able to fail; and according to the condition of these causes, the effects are called "necessary" or "contingent", even though all depend on the divine will as on a first cause which transcends the order of necessity and contingency. But this cannot be said of the human will, nor of any other cause, because every other cause already falls under the order of necessity or contingency, and so it is necessary that either the cause itself can fail, or that its effect is not contingent but necessary. But the divine will cannot fail, and nevertheless not all its effects are necessary, but some are contingent.... [Expositio libri Peryermenias 1.14 (ed. Leonine, t. 1*1, Rome\Paris, 1989: Commissio Leonina\Vrin, lines 438-461).]
Cf. also Compendium theologiae I, cap. 140, ed. Leonine, lines 12-23, Rome, 1979: Editori di San Tommaso [t. 42], concerning the efficaciousness of the divine will and the existence of contingency in creatures. To quote only the key point:
He wills that some things come about necessarily and some contingently, because each is required for the complete being of the universe [quia utrumque requiritur ad completum esse universi][lines 17-19].
44. Owens, Joseph, C.Ss.R., A History of Ancient Western Philosophy, New York, 1959: Appleton-Century-Crofts; concerning Heraclitus, cf. p. 54; concerning Thales, p. 10.
45. Aristotle, Metaph. 4.1 (1003a28-32).
46. 1.3 (983b1-6); Oxford transl. (and hereafter, unless otherwise indicated).
47. It is perhaps worth noting that the etymological background of phusis is the same as the verb "to be", and such words as "fetus"; Latin "fui", French "je fus"
48. 1.3 (983b6-18).
49. 1.3 (984a30-33).
50. BSP, p. 168.
51. Phaedo, 91E-92E. I will use the translation of Harold North Fowler, in Plato, t. I, Euthyphro etc., Cambridge, Mass and London, 1960 [first printed 1914]: Harvard U.P. and Heinemann.
52. Cf. Plato, Phaedo, already at 79A, where we are presented with "two kinds of existences" (tr. Fowler): duo eidé ton onton, the visible and the invisible, the changing and the unchanging.
53. I would say that Aristotle's conception of matter as potency to substantial being is a most important existential step. It makes possible the rejection of the ancient doctrine that nothing comes to be or ceases to be, something that even Plato's doctrine of the receptacle in the Timaeus did not do.
54. Cf. Plato, Timaeus 49A-50A; 51E-52D. For 52D, I prefer the French translation by Albert Rivaud, in Platon, Œuvres Complètes, tome X, Timée - Critias, [3me édition] Paris, 1956 : Société d'Édition « Les Belles Lettres » :
Vous avez ainsi en bref le raisonnement déduit des hypothèses que j'ai hasardées, savoir qu'il y a l'être absolu, la place où nait l'être relatif, et ce qui nait, trois termes existant de trois façons différentes et qui sont nés avant le Ciel. (caps and italics mine)
The Greek has "… on te kai choran kai genesin einai, tria triché…", thus presenting "einai", "esse", in three modes. F. M. Cornford, Plato's Cosmology, New York, 1957: Liberal Arts Press [original 1937, Routledge and Kegan Paul], has "… there are Being, Space, Becoming - three distinct things - …"
55. BSP, p. 168. Gilson does not say so, but he is quoting the sed contra argument of ST1.104.4, which inquires whether anything will be annihilated.
56. Consider the following remark of Thomas, in In De caelo 218 (468 ):
… intelligendum est quod optimum in rebus est permanentia. Quae quidem in substantiis separatis est absque omni motu; et quidquid permanentiae est in aliis rebus, illinc derivatur. Et inde est etiam quod supremum caelum, quod est propinquissimum substantiis separatis, suo motu diurno est causa sempiternitatis et permanentiae rerum; et ideo maxime attingit ad similitudinem primi principii. Superiores autem planetae sunt magis causa permanentiae et durationis quam inferiores: unde Saturno attribuuntur res fixae…
57. Here I use the translation of H.N. Fowler in Plato, t. VII, Theaetetus - Sophist, Cambridge, Mass and London, 1967 [first printed 1921]: Harvard U.P. and Heinemann.
58. F. M. Cornford, Plato's Theory of Knowledge, New York, 1957: Liberal Arts Press [originally Routledge, 1934], translates "perfectly real".
59. Aristotle, Metaphysics 9.6 (1048a25-b17; 35-36).
60. Aristotle, De anima 3.7 (431a4-8); Thomas, Sentencia libri De anima 3.6 (Leonine lines 8-52).
61. Aristotle's ability to distinguish between the potency to material substantial being and the privation involved in generation and corruption is important in this regard; the Platonic receptacle combined potency with privation, thus itself claiming the status of the "this"; this left Plato somewhat in the position of the Presocratics (at least as regards particular coming to be), that nothing ever really comes to be or ceases to be: the so-called material substances are mere "such-es". Cf. Phys. 1.9 (191b35-192b7), the entire chapter; Thomas, CP 1.15. - In fact, in Phys. 1, Aristotle does not solve the problem of generation and corruption altogether adequately, through the notions of act and potency; he simply mentions this possible approach: Phys. 1.8 (191b28-29), saying he will speak of it elsewhere; Thomas, CP 1.14 (127 ), sends us to Metaph. 9 for this; I suggest Metaph. 9.6 (1048b9); Thomas, CM 9.5 (1828) as at least "seminal" in this regard.
62. Aristotelis, Metaphysica, ed. W. Jaeger, Oxford, 1957: Clarendon Press, 9.6 (1048a30-32).
63. Here I am using the translation published in the Marietti edition of CM, at 9.5. I am assuming that it is Moerbeke. The Thomas statement is in #1825.
64. Aristotle, Metaph. 9.6 (1048a25-30); CM 9.5 (1823-1824),
65. Aristotle, Metaphysics 9.3 (1047a30-b1), italics in the Oxford translation (I have changed "actuality" to "act" in the translation, and made other revisions).
66. CM 9.3 (1805-1806). I have made some effort to indicate the words of Aristotle by small caps. This at least suggests how Thomas works as commentator.
67. Cf. Metaph. 9.6 (1048a35-b17). On an "analogizing" approach to being, cf. Plato, Theaetetus 185C-186D, especially at 186C: "analogismata".
68. Cf. my paper: "St. Thomas and the Distinction between Form and Esse in Caused Things", Gregorianum 80 (1999), pp. 353-370.
69. My general point in this paper bears on Aristotle, not Plato; the difficulties of seeing the embryonic philosophy of being are increased as we go back.
70. On the relation called "measure of being and truth", see Thomas's CM 5.17 (Cathala #1003); on "modus" (i.e. "measure"), as pertaining to a thing's being proportionate to its efficient cause, see ST 1.5.5 (31a39-42). As Thomas says in CM 5.17 (Cathala #1027), summing up the discussion of "measure of esse": "Everything is measured by that on which it depends": this is clearly not "measure" in the properly quantitative sense, but demands a conception of ontological hierarchy, and an appreciation of the extent to which the cause, as cause, is principle of knowledge ("measure") of the effect.
71. SS 3, lines 22-39.
72. See my paper, "The Number and Order of St. Thomas's Five Ways," Downside Review 92 (1974), 1-18 (especially pp. 11-17), for an indication of the importance for Thomas of the presentation of act and potency in Aristotle's Metaph. 9.6 and 9.8-10.
73. I underline the doctrine of the primacy of that ousia that has simplicity as well as act (cf. Aristotle, Metaph. 12.7 [1072a31-32]); CM 12.7: #2524.]
What we should stress is that Thomas reads Aristotle's ch. 8 as clearly saying that what precedes it was about the first principle and first of beings. (CM 12.9 ). There must be one such, for the one movement of the universe. And then there are secondary separate substances.  He agrees with Aristotle against Avicenna that it is both possible and fitting that the first principle of all, the principle of immaterial substances, be the source of the first of all corporeal movements.  There is an order among the separate substances in keeping with the sort of movement they cause. Aristotle himself says this (Metaph. 12.8 [1073b2]), and Thomas stresses the greater nobility of what is prior among them .
In this connection, I must mention In De caelo 2.28 (463 ), which has Aristotle on the order of God and separate entities. In this passage, Thomas makes no objection to placing in a single order God and the lesser separate entities. However, he reads Aristotle's two words, "have" and "participate", as distinguishing God from the lesser separate entities. Aristotle has:
To men oun echei kai metechei tou aristou, to d'aphikneitai [eggus] di'oligon…
And he says that that which in the order of things is supreme has and participates in the best, without any movement; which indeed happens to the separate substances, which are altogether immobile. But he says "has" because of the supreme among the causes, which is the highest God, who is the very essence of goodness; but he says "participates" because of the lower separate substances, which have being [esse] and goodness from another: for to "participate" is nothing other than to partially receive from another. This, therefore, is the first and highest order of beings... But the second order he distinguishes, saying that there is something which closely touches that best through few movements; such as the supreme sphere, which to this extent is said to approach to that best, inasmuch as it pertains to it to be the universal cause of bodies, and the cause of their permanence…. [463 (6)]
74. Cf. e.g. CP 8.2 (975 ):
… sed si fit totum ens, quod est fieri ens inquantum est ens, oportet quod fiat ex penitus non ente: si tamen et hoc debeat dici 'fieri' (aequivoce enim dicitur, ut dictum est).
The backward reference is to the previous paragraph, 974 , where we are told:
Et quia omnis motus indiget subiecto, ut hic Aristoteles probat et rei veritas habet, sequitur quod productio universalis entis a Deo non sit motus nec mutatio, sed sit quaedam simplex emanatio. Et sic fieri et facere aequivoce dicuntur in hac universali rerum productione, et in aliis productionibus.
And cf. ST 1.45.2.ad 2, and SCG 2.37 (ed. Pera, #1130, e) and f)). In this last passage, Thomas says:
Nevertheless, on the basis of some likeness, we transfer the word "making" [factio] to that origin [sc. totius entis], so that we say "made" [facta] of whatever things the essence or nature has its origin from others.
75. Cf. e.g., Bradshaw, David, "Neoplatonic Origins of the Act of Being" [to be published in the Review of Metaphysics]. I am indebted to this paper for his reference to Charles Kahn, "Why Existence Does Not Emerge as a Distinct Concept in Ancient Greek Philosophy", in Philosophies of Existence: Ancient and Medieval, ed. Parvis Morewedge, New York, 1982: Fordham University Press, pp. 7-17. Bradshaw explains (with approval) Kahn's assumption that the Greeks do not in fact have such a notion, on the basis of the Aristotle's making form the cause of being. [B. refers to 1043a2 and 1041b4-33] He, Bradshaw says:
Form is the cause of being of something only in the sense that it makes the thing to be that thing, rather than something else; it is the source of the thing's specificity, of its existence qua entity of that type. Kahn's point is that the Greeks do not address the nature of existence as such, as opposed to the existence qua a particular type of thing that is imparted by form. [Bradshaw typescript, p. 1]
This suggests to me a failure to appreciate the species from the viewpoint of existence. As Thomas says, paraphrasing Aristotle:
And he [Aristotle] says that if the universal is said of many in function of one intelligibility [rationem] and not equivocally, the universal as regards what pertains to reason [quantum ad id quod rationis est], that is, as regards science and demonstration, will not be less of a being [minus ens] than the particulars, but rather more, because the incorruptible is more of a being [magis ens] than the corruptible, and the universal intelligibility [ratio universalis] is incorruptible whereas the particulars are corruptible, corruptibility happening to them in function of the individual principles, not in function of the intelligibility [rationem] of the species, which is common to all and preserved by generation; thus, therefore, as regards what pertains to reason, the universals are more [magis sunt] than the particulars, but as regards natural subsistence [quantum uero ad naturalem subsistenciam], the particulars are to a greater extent [magis sunt], [and thus] are called "primary and principle substances". [Expositio libri Posteriorum, 1.37 (ed. Leonine, lines 173-187, commenting on Aristotle, 85b15; Spiazzi ed., #330).]
76. The next four paragraphs are taken from my paper: "St. Thomas, the Fourth Way, and Creation", The Thomist 59 (1995), pp. 371-378.
77. ST 1.2.2: "From any effect one can demonstrate the existence of its proper cause, if, of course, its effects are better known to us; because, since effects depend on a cause, the effect being posited, the cause must, by priority, exist."
78. Here, I am in disagreement with Leo J. Elders, The Philosophical Theology of St. Thomas Aquinas, Leiden, 1990: Brill, p. 115, who sees in the first stage of the Fourth Way only formal causality. See my review-article of this work, in Science et Esprit 44 (1992), pp. 205-220. - So also I am in disagreement with Louis Charlier, "Les cinq voies de saint Thomas. Leur structure métaphysique", in L'Existence de Dieu, Tournai,1963: Casterman, p. 213, n. 96.
79. I say "almost", since Thomas has in view, not merely the Aristotelian theory of the heavens, but, more metaphysically, his own doctrine of the incorruptibility of the human soul. - On the possible and the necessary described as "differences" proper to that-which-is, see Thomas, In Periherm. 1.14 (ed. Leonine [new edition, 1989], lines 438-454); in Thomas's In Metaph., 6.3 (1220), they are called "accidents", obviously in the sense of properties; for presentations of the necessary and the contingent as the "perfect" and the "imperfect" in the order of being, see ST 1.79.9.ad 3; for the incorruptible and the corruptible as "grades" of being, "esse", see ST 1.48.2 (305a41-45); see also Compendium theologiae 1.74.
80. See ST 1.19.6 (136b1).
81. See, among many possible texts, Thomas's Quaestiones de anima 1.ad 17:"...though being [esse] is most formal of all [formalissimum inter omnia], still it is also most communicable [maxime communicabile], though it is not communicated in by inferiors and superiors in the same measure. Thus, the body participates in the esse of the soul, but not in such a noble way as does the soul." (ed. James H. Robb, Toronto, 1968: Pontifical Institute of Mediaeval Studies, p. 63; my translation).
82. Thomas, In Symbolum Apostolorum expositio, in Opuscula Theologica, vol. 2, ed. R. Spiazzi, O.P., Rome/Turin, 1954: Maritetti, pp. 193-217. Concerning the existence of God, see #869; concerning creation, see #878.
83. All five ways are metaphysical, but the Fourth is primary in this regard. All reduce to the priority of act over potency, and so to the "magis" and "minus" as regards the ratio essendi. See St. Thomas, De substantiis separatis c. 7, lines 47-52 (Opera omnia t. 40, Rome, 1969: Ad Sanctae Sabinae): "Manifestum est autem quod cum ens per potentiam et actum dividatur, quod actus est potentia perfectior et magis habet de ratione essendi; non enim simpliciter esse dicimus quod est in potentia, sed solum quod est actu" (my underlining).
84. Joseph Owens, The Doctrine of Being…, pp. 89-90, has a helpful review of positions. I note (in n. 33, at p. 90) that P. Wilpert in 1940 gave it an early dating on the basis of its conception of the Aristotelian doctrine of truth. The others seem to accept it as late and the product of someone like Pasicles. What is important is that it is regarded as "genuinely Aristotelian" by Luthe, Jaeger, Ross, Owens, etc. Dumoulin (see below) sees it as not Aristotelian in that sense.