Doolan G., Aquinas on Separate Substances and the Subject Matter of Metaphysics DSTFM (2011)

8/11/2019 Doolan G., Aquinas on Separate Substances and the Subject Matter of Metaphysics DSTFM (2011)

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347AQUINASON SEPARATESUBSTANCES

Documenti e studi sulla tradizione fi losofica medievale XX I I (2011)

GREGORY T. DOOLAN

Aquinas on Separate Substances

and the Subject Matter of Metaphysics

On more than one occasion in his wri tings, Thomas Aquinas provides ananswer to a question that seems to remain unanswered in AristotlesMetaphysics : Is metaphysics a universal science whose subject matter isbeingqua being, or is it a special science whose subject is one typeof being,namely, separate substance1 ? In the course of answering this question,

Thomas is careful to show how the separate substance that he calls God isrelated to the subject matter of metaphysics. His treatment of this topic hasreceived much attention from scholars2 . What has received less attention,

1 I n Book I V, c. 1 of the Metaphysics, Ar istotle presents the subject matter of this science asbeingquabeing and, hence, as universal i n scope (1003a20-31). I n Book V I , c. 1, however, afterreiterating this view, he proceeds to show that it belongs to this science to study what isseparable and immovable and, hence, divine. For this reason he refers to this science astheology and also calls it first philosophy, noting that it deals with the highest genus. As

Aristotle himself observes, this leads to the question whether first philosophy is indeeduniversal, or whether it studies only one type of being, what he terms separate substance(1025b1-1026a32). In short, the question arises whether Aristotle is identifying two distinctsciences or a single, unif ied science. F or di scussions of this problem, see I. DRING,Aris toteles.

Darstellung und Interpre tation seines Denkens,C. Winter - Universittsverlag, H eidelberg 1966,pp. 594-599 ; E . KNIG,Ar istoteles erste Phi losophie als universale Wissenschaft von den APXAI, Archiv fr Geschichte der Phi losophie , 52, 1970, pp. 225-246; J . OWENS, The Doctrine of Beingin the Aristotelian Metaphysics, Ponti fical I nstitute of M ediaeval Studies, Toronto 19783, esp. pp.X I I I -XXVI I , 35-67 ; ID., The Doctrine of Being in the AristotelianMetaphysics Revisited, in P.M OREWEDGEed., Philosophies of Existence, Ancient and Medieval,Fordham University Press, NewYork 1982 ; A. MANSION,Lobjet de la science philosophique supreme daprs Aristote, Mtaphysique,E,

I

, in Mlanges de Philosophie Grecque offerts Mgr Dis, Vrin, Pari s 1956, pp. 151-168; ID.,Philosophie premire, philosophie seconde et mtaphysique chez Aristote, Revue philosophiquede Louvain , 56, 1958, pp. 165-221 ; M. FREDE , The Unity of General and Special Metaphysics:

Aristot les Conception of Metaphysics , in I D.,Essays in Ancient Philosophy, University of MinnesotaPress, Minneapolis1987, pp. 81-95.

2 See, e.g., S. NEUMANN, Gegenstand und Methode der theoretischen Wissenschaften nachThomas von Aquin aufgrund der Expositio super librum Boethii De Trinitate , Beitrge zurGeschichte der Phi losophie und Theologie des Mittelalters , 41/2, 1965, pp. 7-20 ; J . C. DOI G,Science premire et science universelle dans le Commentaire de la mtaphysique de saint Thomas

dAquin, Revue phil osophique de Louvain , 63, 1965, pp. 41-96 ; ID.,Aquinas on Metaphysics :A Historico-Doctrinal Study of the Commentary on the Metaphysics, Ni jhof f, The Hague 1972, pp.55-94 ; J . COUNAHAN, The Quest for Metaphysics, The Thomist , 33, 1969, pp. 519-572 ;J . F.


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348 GREGORYT. DOOLAN

however, is how he considers those other separate substances, what theologianscall angels, to be related to that subject matter3 . Indeed, Thomas himself

does not address this topic in detail. To the extent that he does address it, hisconsiderations present seemingly inconsistent views. In this article, I intendto show that despite these facts, one can nevertheless discern in Thomasswritings a coherent and consistent account of how created separate substancesare related to the subject matter of metaphysics.

Aquinas provides us with two majorex professo treatments regarding thesubject matter of this science: in his early commentary on Boethiuss DeTrinitate (ca.1257-1259) and in his later commentary on AristotlesMetaphysics(ca. 1270-1271/1272)4 . It is in these two works that we find his clearestaccount of how the sciences study the separate substances, both God and the

angels. For that reason, I will begin with a summary and analysis of therelevant passages in each work. Having done this, I will then show how, for

Thomas, created separated substances can be both the causes of the subjectmatter of metaphysics and included under it.

I

TEXT1 : I NDETRINI TATE , Q. 5

In his commentary on BoethiussDe Trinitate, Thomas dedicates Questions5 and 6 to examining the division and methods of the sciences. In q. 5, a. 1 thefirst topic that he considers is whether it is fitting to divide speculative

WIPPEL , Metaphysical Themes in Thomas Aquinas, The Catholic University of America Press,Washington, D. C. 1984, pp. 55-67 ; ID., The Metaphysical Thought of Thomas Aquinas,TheCatholi c University of America Press, Washington, D.C. 2000, pp. 3-22 ; R. MCI NERNY , PraeambulaFidei: Thomism and the God of the Philosophers,The Catholic University of America Press,Washington, D.C. 2006, pp. 210-218 ; L . DEWAN, O. P., What Does It Mean to Study Being as

Being, in Form and Being: Studies in Thomistic Metaphysics,The Catholic University of AmericaPress, Washington, D.C. 2006, pp. 13-34 ; A. ZIMMERMANN, Ontologie oder Metaphysik? Die

Diskussion ber den Gegenstand der Metaphysik im 13 . und 14 . Jahrhundert ,2ndrev. ed., Peeters,Leuven 1998, pp. 200-223. See this last work for an overview of other medieval accounts of thesubject matter of metaphysics.

3The most thorough presentation of Thomass phi losophical account of the angels is offeredby J . Collins in his work The Thomistic Philosophy of the Angels, The Catholic University ofAmerica Press, Washington, D.C.1947. F or a more recent although less thorough treatment ofThomass angelology, see T. SUAREZ-N AN I , Les anges et la philosophie: Subjectivit et fonctioncosmologique des substances spares la fin du XIIIe sicle, Vrin, Paris 2002 (tudes dephilosophie mdivale 82), esp. pp. 27-53, 103-142.

4Dating of Thomass texts follows J .-P. TorrellsSaint Thomas Aquinas, vol. I , The Person and HisWorks, rev. ed., trans. R. Royal, The Catholic University of America Press, Washington, D.C. 2005.


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science into three parts : natural, mathematical, and divine5 . Thomas concludesthat this is indeed a fi tting division since it is based upon the degree to which

the objects considered are separated from matter and motion. As he explains,some objects of speculative knowledge depend upon sensible matter both tobe and to be understood, as flesh and bones must be included in the definitionof man. Such objects are studied by physics, or natural science. Other objectsdepend upon sensible matter only to be, but not to be understood since it doesnot enter into their definition, as with l ines and numbers. Such are the objectsstudied by mathematics 6.

Finally, Thomas explains, there are objects that do not depend uponmatter because they can exist wi thout i t, and he identifies two ways in whichthis can occur7 . Either they never exist in matter, as is the case with God and

the angels ; or they exist in matter in some instances but not in others, as isthe case with substance, quali ty, being (ens), potency, act, one and many, andso forth. The science that studies both sorts of objects, he tells us, is theologyor divine science because the principal object considered in i t is God. L est wewonder whether he is referring to revealed theology, Thomas adds that thisscience is also called by another name: metaphysics. This name, he explains,means beyond physics (trans physicam) because it i s learned after the studyof physics. And it is also called first philosophy because all of the othersciences follow this one, receiving their principles from it8 .

In this first article, then, we find Thomas clearly stating that it belongs tometaphysics to study the angels at least in part. For we also find himidentifying two classes of objects that this science studies. The first class

5 Super Boetium De Trinitate (hereafterIn De Trin.), q. 5, prologus, in SANCTITHOMAEDEAQUINOOpera Omnia, vol. 50, Commissio L eonina - Vri n, Roma - Paris 1992, p. 136, lin. 1-4. For discussionsof Questions 5 and 6 in this work, see P. PORROed., Tommaso DAquino, Commenti a Boezio,Rusconi,M ilan 1997, pp. 55-367 ; NEUMANN, Gegenstand und Methode der theoretischen Wissenschaftencit. ; L.E LDERS, Faith and Science: An Introduction to St. Thomas Expositio in Boethii De Trinitate,Herder,Rome 1974 ; H. WEIDEMANN, Metaphysik und Sprache: Eine sprachphilosophique Untersuchung zuThomas von Aquin und Aristoteles,K arl Albert Publi shing House, Freiburg-Munich 1975; W IPPEL,

Metaphysical Themescit.,pp. 69-104; ID., Metaphysical Thought cit.,pp. 8-9, 17, 23-35. See alsoA.Maurers translation and notes on this text in his work, The Division and Methods of the Sciences, 4th

ed., trans. by A. M AURER, Pontifical Institute of Mediaeval Studies, Toronto 1986. Regarding theinfluence of Avicenna in parts of this work, see WIPPEL , Metaphysical Themes cit.,pp. 37-53.

6In De Trin.,q. 5, a. 1, ed. cit., p. 138, lin. 141-154.7Thomas leaves unstated the conclusion that such objects would thus also not depend upon

sensible matter to be understood.8In De Trin., q. 5, a. 1, ed. cit., p. 138, lin.154-167. Thomas concludes this arti cle by noting that

it is impossible for there to be any objects that depend upon matter to be understood but not for themto be since the intellect by its nature is immaterial. Thus, there is no fourth type of science. I n short,the division of speculative science stated at the outset is fitting ed. cit., p. 138, lin.168-172.


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(consisting of God and the angels) entirely excludes matter ; for that reason, ithas been termed by some scholars as positively immaterial. By contrast, the

second class (consisting of substance, being, and the like), does not entirelyexclude matter ; rather, i t consists of objects that can be in matter but need notbe, and for that reason it has been described by some scholars as negativelyimmaterial or neutrally immaterial9 . We are left, then, with the question ofhow God and the angels, both of which are positively immaterial objects, relateto the negatively immaterial objects that metaphysics also studies.

Thomas provides an answer to this question in q. 5, a. 4, where heidentifies the subject matter of metaphysics. The question posed in thisarticle is whether divine science concerns those things that are separate frommatter and motion10 . Thomas begins his response by asserting that any

science is only perfected through a knowledge of the principles of its subjectmatter. Having noted this fact, he proceeds to explain that there are two typesof pr inciples : those that are complete natures in themselves, and those thatare not. As examples of the former type of principle, he gives the heavenlybodies and the elements. Following the physics of his time, he explains thatthe heavenly bodies are principles of terrestrial bodies and that the elementsare principles of mixed bodies. Moreover, both the heavenly bodies and theelements are complete natures in themselves. For that reason, they can bestudied in two respects : they can be studied in one science simply inasmuchas they are principles of other things, but they can also be studied in anotherscience that considers them in their own right. Thus, there is a science thatstudies the heavenly bodies independently of terrestrial bodies (the sciencewe would today call astronomy), and there is also a science that considers theelements independently of mixed bodies (a branch of the science we wouldtoday call chemistry). I n contrast to these sorts of principles, those principlesthat are not complete natures in themselves can only be studied in onescience: the science in which they are treated as principles of other things.

Thomas gives the examples of unity as the principle of number, a point as theprinciple of l ines, and form and matter as the principles of natural bodies11.

He next notes that all beings, inasmuch as they share in being (in ente),have certain principles in common that are the principles of all beings. CitingAvicenna, he notes that these principles can be called common in two ways:by predication or by causality12 . Principles are common by predication when

9 See, e.g., M. A. GLUTZ, Being and Metaphysics, The Modern Schoolman , 35, 1958, pp.271-285, p. 276 ; W IPPEL , Metaphysical Themes cit.,pp 30, 72-73 ; ID., Metaphysical Thought cit.,pp. 8-9, 52-53.

10In De Trin. q. 5, prologus, ed. cit., p. 136, lin. 6-9.11In De Trin., q. 5, a. 4, ed. cit., p. 153, lin. 80-107.12

AVICENNA, Sufficientia, I, c. 2, Venice 1508, f. 14va, lin. 6-30.


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they can be predicated of many things, as the term form is common to allforms because it can be predicated of all forms. Citing Aristotles Metaphysics,

Thomas explains that in this sense there are principles common to all beingssecundum analogiam13 . By contrast, principles are common by causalitywhen the causal principle of many things is numerically one. Following thephysics of his day, he gives as an example the sun, which is numerically onething and yet is the principle of all generable things. Similarly, there arecertain things that are each one in number and yet are the principles of all

existing things. In this way, he explains, the principles of accidents arereduced to the principles of substance, and the principles of corruptiblesubstances are reduced to the incorruptible substances. All beings, therefore,are reduced to certain principles following an ordered gradation14 . Looking

to the summit of this ordered gradation, he explains,

And since that which is the principle of being (essendi) for all things must bemaximally a being (maxime ens), as is said in Metaphysics I I , such principles [i.e.,of all beings] must be most perfect. Hence, they must be maximally in act, so thatthey have no potency or the least potency since act is prior and superior topotency, as is said in MetaphysicsIX. And for this reason, they must be separatefrom matter, which is in potency, and from motion, which is the actuality of thatwhich exists inpotency. And such [principles] are divine things (res divinae),since, as is said in Bk VI of the Metaphysics,if the divine exists anywhere, in such

a nature it exists especially, namely, in what is immaterial and immobile 15

.

Thus far in this article, Thomas has not explicitly identified these divinethings by name. Their key characteristic that he has identified, however, isthat they are separate from matter and motion. Since these principles are notcommon merely by predication, we can conclude that the divine beings are

13 See Metaphysics , X I I , 4, 1070a31-33 ; 5, 1071a30-35.14In De Trin .,q. 5, a. 4, ed. cit., p. 153, lin. 108-131.15In De Trin ., q. 5, a. 4, ed. cit., pp. 153, lin. 131-154, li n.143 : Et quia id quod est

principium essendi omnibus oportet esse maxime ens, ut dicitur in II Metaphysicae, ideohuiusmodi pr incipi a oportet esse completissima ; et propter hoc oportet ea esse maxime actu,ut nihil vel minimum habeant de potentia, quia actus est prior et potior potentia, ut dicitur inIX M etaphysicae ; et propter hoc oportet ea esse absque materi a, quae est in potentia, et absquemotu, qui est actus exsistentis in potentia. Et huiusmodi sunt res divinae, quia si divinumalicubi exsistit, in tali natura, immateriali scilicet et immobili, maxime exsistit, ut dicitur inVI M etaphysicae . Emphasis added in translation. Unless otherwise noted, all translations aremy own. See Metaphysics ,I I , 2, 993b26-31 ; IX , 8-12, 1049b4-1051a33 ; VI , 1, 1026a20. ThatThomass reference to such principles (huiusmodi principia) refers to principles of all beings(principia omnia entium) i s clear from the lines that precede and fol low this observation. SeeIn

De Trin .,q. 5, a. 4, ed. cit., pp. 153, li n. 108-113 ; 154, l in. 143-148.


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not the negatively immaterial objects such as substance and being (ens) thatThomas identifies in q. 5, a. 1. Rather, they must be positively immaterial, and

in fact he says as much as the passage continues. Still, from this quotedpassage alone, we can infer that Thomas is not only identifying God assomething divine, but the angels as well16 . This reading is confirmed by hisobservation that these principles either have no potency or the least potencypossible. Only God has no potency; hence, the reference to beings with theleast potency possible is a reference to the angels. In reply to the fourthobjection, Thomas explains that Gods essence is pure actuality whereas theessence of an angel, in contrast, is really distinct from itsesseand thus standsin potency to itsesse. Still, an angel does lack the potency of matter and so,also, the potency that motion entails. Thus, of all beings that possess potency,

angels have the least17 . And it is because they are separate from matter andmotion that Thomas includes them together with God as divine beings.

Having identified the immaterial nature of the causal principles of allbeings, Thomas continues in the body of article 4 by returning to his earlierdistinction between two sorts of principles and how they are studied in thesciences. He notes that the divine things are not only principles of all beings,but they are also complete natures in themselves. Thus, like the heavenly bodiesand the elements, they can be studied in two ways: as principles and as thingsin their own right. Nevertheless, he identifies an obstacle to studying them inthis latter way not an obstacle due to the things themselves but one that isdue to the limitations of the human mind. In themselves, these principles arein fact most knowable, but our intellects stand to them as the eye of the owl doesto the light of the sun. Through the light of natural reason, we can only reachthese divine things to the extent that we are led to them by their effects. It isin this way, Thomas explains, that the philosophers attain knowledge of thesefirst principles18 . Hence, such divine things are not treated by philosophersexcept insofar as they are the principles of all things19 . Thus, he concludes,

16 We might wonder, then, why the first line of the above quoted passage speaks in terms of

a single principle of all things. This is because Thomas is there referring to the principle of theesse of all things (principium essendi omnibus), whereas earlier in q. 5, a. 4 he had referredinstead to the principles of all beings(principia omnium entium). SeeIn De Trin., q. 5, a. 4, ed.cit., p. 153, lin.111, 120, 122-123, 126, 130-131. As will be discussed below, Thomas concludesthat only God can be the direct and immediate cause of esse .

17In De Trin ., q. 5, a. 4, ad 4, ed. cit., pp.155, lin. 263 - 156, lin. 304. See alsoDe ente et essentia(hereafter De ente), c. 4, in SANCTITHOMAEDEAQUINOOpera Omnia, vol. 43, Commissio Leonina,Rome 1976, pp. 376, lin. 90 - 378, lin. 201.

18In De Trin.,q. 5, a. 4. Offering scriptural support for thi s positi on, Thomas cites Romans I,20 : Invisibil ia Dei per ea quae facta sunt intellectu conspiciuntur (ed. cit., p. 154, li n. 156-157).

19In De Trin .,q. 5, a. 4, ed. cit., p. 154, lin. 157-159 : Unde et huiusmodi res divinae non

tractantur a philosophis nisi prout sunt rerum omnium principia .


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they are treated in the science that studies what is common to all beings, thescience that has as its subject matter being inasmuch as it is being (ens in

quantum ens). And it is this science that philosophers call divine science20

.Despite the limitation on the part of the human intellect, Thomas notes thatthere is another way by which these divine things can be known not as theireffects reveal them but, rather, as they reveal themselves. And in this way, theycan be studied as they subsist in themselves rather than simply as the principlesof all things. Having drawn this distinction, he identifies two types of theologyor divine science. One is the divine science that we have already addressed hereand in q. 5, a. 1. This science does not consider divine things as its subjectmatter but only as the principles of its subject matter ; it is the theology of thephilosophers, which is also called metaphysics. The other type of theology,

however, does consider divine things as its very subject matter, and this is thetheology taught in the science that he terms Sacred Scripture21.

Thomas notes that both of these sciences consider things that are separatefrom matter and motion, but he is careful to add that they do so in differentways since something can be separate in one of two ways. According to the fi rstway, a thing by its very nature is incapable of existing in matter and motion.

This is the positive mode of immateriality that he had described in q. 5, a. 1. Asin that article, here in article 4 he again identifies God and the angels (Deus et

angeli) as examples of the sorts of things that are positively immaterial.According to the second way, it does not belong to the nature of a thing to existin matter and motion ; rather such things are sometimes found separate fromthese conditions, and sometimes not. This is the negative mode of immateriali tythat he had described in q. 5, a. 1. Offering a shorter list of the examples givenin that article, he now identifies being (ens), substance, potency and act. As heexplains, these things are separate from matter and motion in this second waybecause they do not depend upon either matter or motion according to being(secundum esse) in the way the objects of mathematics do, which exist insensible matter even though they can be understood without it22 .

Having drawn this distinction, Thomas outlines how the two kinds of

theology study the two kinds of immaterial things. Philosophical theologystudies as its subject matter things that are separated in the second sense (thenegatively immaterial), but it studies things that are separated in the firstsense (the positively immaterial) only as theprinciples of its subject matter.By contrast, the theology of sacred scripture treats things separated in the

20In De Trin .,q. 5, a. 4, ed. cit., p.154, lin. 143-157.21Ibid ., p. 154, lin. 157-182.22Ibid ., p. 154, li n. 182-198. Cf. ibid., ad 5, p.156, lin. 305-313.


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fi rst sense as its subject matter, but also considers things that exist in matterand motion to the extent that they are needed to make divine things clear 23 .

We now have a better sense of how Thomas considers both God and the angelsto be studied in metaphysics : they are not treated as its very subject matter ;rather, they are treated simply as the principles or causes of that subjectmatter, which is what Thomas termsenscommune, being in general24 .

Thus far in article 4 Thomas has simply grouped God and the angelstogether as positively immaterial beings, making no explicit distinction betweenthem as they are either in themselves or as principles of other beings. In hisreply to the third objection, however, he identifies an important differenceregarding how God and the angels are studied. Thomas explains that the divinescience received through divine inspiration does not treat angels as its subject

matter ; quali fying what he had said in theresponsio, he notes that the angelsare only included in that science as among those things that make its subjectmatter clear. Thus, angels are treated in the science of Sacred Scripture asother creatures are. But in the divine science that the philosophers teach , headds, the angels (which they call Intelligences) are considered from the sameperspective (eadem rationem) as the first cause, which is God, insofar as theyare also secondary principles of things, at least through the motion of thespheres. But no physical motion can happen to them25 .

Unfortunately, Thomas provides no explanation here regarding eitherwhat it means for the angels to act as secondary principles or how they do sothrough the motion of the spheres. I will return to these two assertions belowto consider them in l ight of what Thomas says elsewhere about the angels. Fornow, suffice it to say that in his commentary on Boethiuss De Trinitate,heconcludes that both God and the angels are studied in metaphysics, not as itssubject matter (which isenscommune), but as the principles of that subjectmatter, although angels are in some sense only secondary principles.

TEXT2 :INMETAPHYSI CAM, PROEMIUM

In the Proemium to his commentary on Aristotles Metaphysics, Thomasobserves that when several things are ordered toward one thing, that onething is the rule or ruler of those others. Thus we find that all of the arts and

23In De Trin .,q. 5, a. 4, ed. cit., p. 154, lin. 198-206.24 SeeIn De Trin .,q. 5, a. 1, ad 7, ed. cit., p. 141, lin. 338-342.25In De Trin .,q. 5, a. 4, ad 3, ed. cit., p. 155, lin. 239-250 : Sed in scientia divina quam

phil osophi tr adunt consideratur de angeli s quos intelli gentias vocant, eadem ratione qua et deprima causa, quae Deus , in quantum ipsi etiam sunt rerum principia secunda, saltem permotum orbium. Quibus quidem null us motus physicus accidere potest .


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sciences are ordered toward one end, namely, to mans perfection, which ishappiness. I t is for this reason that one of these sciences governs the others,

and this science is appropriately called wisdom, for it belongs to the wiseman to set others in order. Thomas goes on to show that it belongs to the mostintellectual science to govern the other sciences, and he shows that thisscience is consequently concerned with the most intelligible things (maximeintelligibilia). What are these things? To answer this question, he proceeds tooutl ine three ways in which something can be considered most intell igible26 .

(1) The first way follows from what is known. As Thomas explains, thosethings from which the intellect acquires certi tude seem to be more intelligible.Now, the intellect acquires certi tude in science from causes ; thus, knowledgeof causes seems to be the most intellectual sort of knowledge, and the science

that considers the first causes seems to be the highest and ruler of the othersciences. (2) The second way follows from the mode of knowledge. Here,

Thomas identifies what is most intelligible by comparing the intellect wi ththe senses. Sense knowledge is a knowledge of particulars whereas intellectualknowledge seems to differ in that it comprehends universals. For that reason,the science that is most intellectual considers the principles that are mostuniversal. These are being (ens) and what fol low upon being, for example, oneand many, potency and act. Such principles should not remain entirelyunexamined because without a complete knowledge of them, one cannot havea knowledge of those things that are proper to any genus or species. And yet,it does not belong to any one of these particular sciences to study theseuniversal principles ; since these principles are needed for knowledge of everyclass of beings, they would for the same reason be treated by every particularscience. It remains, therefore, that they are treated in one universal scienceand that this science is most intellectual. As such, Thomas concludes, itgoverns all of the rest27 .

(3) Finally, the third way in which we can take things to be most intell igiblefollows from the knower himself. Whatever has intellective power does sobecause it is free from matter. As Thomas explains, however, the intellect and

what is intell igible must be proportioned to each other since the intellect andthe intelligible are one in act. What is most intelligible, therefore, must beseparated from matter in the ful lest sense. But what is separated from matterin the fullest sense are things that can be abstracted from sensible matterentirely and not only from designated matter. To illustrate what he means,

Thomas draws some points of contrast. The natural forms considered by

26In duodecim libros Metaphysicorum Aris totelis exposi tio (hereafter In Meta.), M.-R.CATHALA, R. M. SPIAZZI edd.,Marietti, Turin-Rome1950, Proemium, p. 1.

27Ibid .


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natural science are understood universally because they are abstracted fromdesignated matter, but these forms cannot be abstracted from sensible matter

entirely. Unlike natural forms, mathematical objects can be separated inthought, not simply from designated matter but also from sensible matter(secundum rationem), although they cannot be separated from it in theirexistence (secundum esse). Those things, however, that are in the fullest senseseparated from matter are so both in thought andin their existence as well.As examples, Thomas lists God and the Intelligences. Hence, he concludes,the science that considers such things seems to be the most intellectual andgoverns all the rest28 .

In this threefold consideration, then, Thomas presents three classes ofobjects that are most intelligible: (1) the first causes, (2) the most universal

principles, such as being (ens) (principles referred to inIn De Trin. as commonby predication), and (3) God and the Intelligences. He then proceeds to showthat this threefold consideration should be attributed to one and the samescience. First, he identifies classes 1 and 3, noting that it is the separatesubstances that are the universal and fi rst causes of being (universales et primae

causae essendi). Next, he observes that the proper causes of any genus and thegenus itself are studied by the same science, as natural science studies bothnatural bodies as well as the principles of natural bodies. Thus, it belongs toone and the same science to consider separate substances as the common anduniversal causes of the genus that is being in general (enscommune)29 .

In referring to being in general in this way, Thomas does not mean tosuggest that i t is a genus in the proper sense of the term, as he wil l make clearlater in this Commentary30 . Rather, he simply means that class 2 is the subjectmatter of the science in which God and the Intelligences are treated as firstcauses. As he explains, although this science considers all three classes ofobjects, it nevertheless only considers being in general as its subject matter(subiectum). For in any science, causes are not studied as the very subjectmatter of the science; rather, they are studied only insofar as they are thecauses of that subject matter. Knowledge of the causes of some genus is,

instead, the end or goal of any science. And yet, Thomas explains, even thoughbeing in general is the subject matter of this science, the science as a whole isconcerned with what is separate from matter, both in existence and in thought.

Things are said to be separate from matter in both respects, not only becausethey can never exist in matter (as is the case with God and the intellectual

28In Meta ., ed. cit., p. 1.29Ibid ., pp. 1-2.30 See In III Meta ., lect. 8, nn. 430-435, ed. cit, p. 122. For Aristotle on this topic, see

Metaphysics , I I I , 3, 998b21-28.


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substances), but also because they are capable of existing apart from matter(such as being in general). As he notes, it would not be possible for such things

to be separate from matter if they depended upon it in order to exist31

.Thomas concludes this consideration by noting that this science is giventhree names corresponding to the three classes of objects mentioned above.It is called divine science or theology because it studies God and theIntelligences. It is called metaphysics because it studies being (ens) andthose things that follow upon being : in other words, things that are beyondthe physical (transphysica). And it is called first philosophy because itstudies the first causes of things32 .

CONCLUSIONS

In these two texts that we have considered, Thomas expresses a consistentview regarding the subject matter of metaphysics, a view that spans most of hiscareer. Although his treatments of this topic appear in commentaries on theworks of other authors, the ideas expressed are nonetheless Thomass own.

This is clear from the context of the discussion. His consideration of the subjectmatter of metaphysics in his commentary on BoethiussDe Trinitateoccurs inthe context of a question commentary rather than a literal one. And hisconsideration in his commentary on Aristotles Metaphysics occurs in theProemium, where Thomas is writing in his own name. In both works, he comesto the following conclusion : it belongs to metaphysics to study what is separatefrom matter and motion. This includes what I have referred to as the positivelyimmaterial (the separate substances) as well as the negatively immaterial(principles such as being and substance). Nevertheless, metaphysics does nottreat the separate substances as its very subject matter, even though thisscience may be termed divine science or theology. Rather, it studies both Godand the angels as the causes of its subject matter, which is being in general.

From these two texts, we now have a clearer pi cture of how the angels arestudied in metaphysics. Nevertheless, Thomass account raises further

questions. Although he does not consider the separate substances to be thevery subjects of metaphysics, he does consider them to be beings. Hence, itseems that they ought to be included under the genus of enscommune. Thispossibil ity leads to the following questions : (1) Does Thomas indeed considerangels to be included under the subject matter of metaphysics ? (2) And i f so,how does he think they can be principles of a subject matter under which theyare included ? I will address these two questions in the sections that follow.

31In Meta .,Proemium, ed. cit., p. 2.32Ibid .


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I I

In considering this first question, we encounter an aporiafrom the textsconsidered so far. On the one hand, Thomas presents the separate substancessimply as the causes ofenscommuneand does not explicitly present them asincluded under i t. In fact, in his commentary on theDe Trinitatehe goes so faras to say that such divine things are not treated by philosophers exceptinsofar as they are the principles of all things 33. This statement would seemto suggest that Thomas does not view either God or the angels as includedunder the subject matter of metaphysics. On the other hand, in bothcommentaries he presents being (ens) and substance as principles that insome instances exist apart from matter, even though in other instances they

do not. This would seem to suggest that Thomas does view the separatesubstances as included under the subject matter of metaphysics since they areprecisely beings and substances that exist apart from matter 34 .

The solution to thisaporiarests in part in making a distinction between thetwo different types of separate substances identified by Thomas : God and theangels. Time and again throughout his corpus, he concludes that God is notincluded under any genus35 . It might seem, however, that God must at leastfall under the genussubstancesince, as one objection notes in theDe potentia,the fundamental characteri stic of substance is to existper se(per seexistere),a characteristic that most ful ly belongs to God. As Thomas explains in reply,however,ensper seis not the definition of substance since being (ens) is nota genus. Because substance is one of the most universal genera, it cannotproperly be defined. Still he proposes a working definition, explaining thatsubstance is a thing to whose quiddity it belongs to be (esse) not inanother . This definition, however, is not applicable to God since his quiddityis not distinct from his act of being (esse). H ence, Thomas concludes, God is

33In De Trin., q. 5, a. 4, ed. cit., p. 154, lin. 157-159. Emphasis added. For the Latin, see n. 19 above.34 See above, nn. 8 and 31. See alsoIn De Trin .,q. 5, a. 4, ad 5, ed. cit., p. 156, lin. 305-313.

In his Commentary on Ari stotles Metaphysics , Thomas makes this point more clearly. There, heexplains that it belongs to this science to study all substances inasmuch as they are substances(In I II Meta.,lect. 6, n. 398, ed. cit., p. 112). Cf.In XI Meta ., lect. 1, n. 2152-2153, ed. cit., p. 510 ;

In XII Meta ., lect. 2, n. 2427, ed. cit., p. 570.35 See, e.g., Scriptum super Sententiis I (hereafter In I Sent .) d. 8, q. 4, a. 2, ed. P.

M ANDONNET, Lethielleux, Paris 1929, vol. I , pp. 221-223 ; Summa contra gentiles(hereafterSCG), I, c. 25, in SAN CT ITHO MA EDE AQUINOOpera Omnia, vol. 13, Commissio Leonina, Rome1918, p. 76 ; Quaestiones disputate De potentia (hereafter De pot. ), q. 7, a. 3, in Quaestiones

disputatae ,ed. M . PESSION, M arietti, T urin-R ome 1949, vol. I I , pp. 193-194 ; Summa theologiae(hereafter ST), I, q. 3, a. 5, in SAN CT ITHO MA EDE AQUINOOpera Omnia, vol. 4, Ex Typographiapolyglotta, Rome 1888, pp. 43-44.


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not included in the genus substance36 . And so, even though he is immaterial,God is not an example of the sort of immaterial substance that would be

included under the subject matter of metaphysics, enscommune.More to the point, Thomas holds that in no respect is God included underenscommune37. We find him arriving at this conclusion, among other places,in his commentary on theLiber de causis (1272). In the course of addressing theconclusion in Proposition 6 that the First Cause transcends all description,

Thomas explains that the unknown author of this work offers three argumentsto prove this proposition. These arguments follow the three ways in whichsomething can be known : (1) as an effect is known in i ts cause, (2) as somethingis known through itself, and (3) as a cause is known through its effect. Lookingat the second of these three ways, Thomas notes that the author makes clear

why the First Cause is above things that are sensible, imaginable, and corruptible.What that author does not make clear in this Proposition is why God is alsoabove intelligible, sempiternal things (res intelligibiles sempiternas). Thomasadds that Proclus, however, proves this point by saying that all intellectual, orrational, thought is thought about beings (entia)38 : As Aquinas explains,

What is first grasped by the intellect isens ; that in which the character ofensis not found is incapable of being grasped by the intellect. Hence, since theFirst Cause is above ens, it follows that the First Cause is above intelligible,sempiternal things. Now, according to the Platonists, the First Cause is above

ensinasmuch as the essence of goodness and unity (which is the First Cause)also exceeds Separated-Ens-Itself (ipsum ens separatum), as was said above.But according to the truth of the matter, the Fi rst Cause is aboveensinasmuchas it is Infinite-Esse-Itself. Ens, by contrast, is called that which finitelyparticipates esse , and it is this that is proportionate to our intellect, whoseobject is that which is (quod quid est) as is said inDe anima, I I I 39 .

36De pot., q. 7, a. 3, obj. 4, ed. cit., p. 193 ; ibid., ad 4, p. 194 : Substantia est res cuiusquidditati debetur esse non in al iquo (itali cs in original). Cf. other texts cited in n. 35 above. I f God is not i ncluded in the genussubstance, we might wonder why Thomas refers to hi m as a

separate substance. In the same article from the De potentia , Thomas explains in reply to theseventh objection : L icet Deus non pertineat ad genus substantiae quasi i n genere contentum, sicut species vel individuum sub genere continentur, potest tamen dici quod sit i n generesubstantiae per reductionem, sicut principium, et sicut punctum est in genere quantitatiscontinuae, et unitas in genere numeri ; et per hunc modum est mensura substantiarum omnium,sicut unitas numerorum (q. 7, a. 3, ad 7, ed. cit., p. 194).

37 On this point, Thomas is unique among his medieval contemporaries. See Z IMMERMANN,Ontologie oder Metaphysik ? cit.,esp. pp. 251-381.

38 PROCLUS, Proposition 123, in Proclus : The Elements of Theology,2nded., translated withcommentary by E. R. DODDS, Oxford University Press, Oxford 1963, pp. 108-110.

39 Sancti Thomae de Aquino Super Librum de causis expositio (hereafterIn Lib. de caus.), ed.H. D. SAFFREY , Socit Philosophique, Fribourg-Louvain 1954, Prop. 6, pp. 46, lin. 13 - 47, lin.


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This passage is of interest to us here for three reasons. (1) First, it shows thatThomas considers God to be, in a sense, beyond being (ens). Clearly, however,

he does not accept what the Platonists mean when they speak of God in thisway. According to Thomas, God is not beyond being principally because he isGoodness Itself or Unity Itself ; rather, he is beyond being principally becauseas Esse Itself he is infinite40 . Unlike these Platonists, then, Thomas is notclaiming that God is not a being. To the contrary, because he considers God tobeIpsumEsse, Thomas concludes that God is the maxime ens41. In short, thecontrast that he is drawing here is not one between being (ens) and non being(non ens), but between finite being (ens finitum) and infinite being (ensinfinitum). Only the former constitutes the subject matter of metaphysics.

Thus, we find him elsewhere explicitly contrasting ens commune with ens

increatum42. (2) The second point of interest regarding this passage followsfrom the first : God is beyondens commune not simply because he is its causebut because he is infinite in being (esse). I ndeed, as we will see below, it is onlybecause God is infinite that he can be the first cause of all beings. (3) F inally,the third point of interest for us in this passage is Thomass conclusion that Godtranscends sempiternal things because he transcends ens (commune). Thismeans that, in contrast to God, sempiternal beings (namely, things that areabove time and motion) such as angels do not transcend being in general43.

It is clear, then, that if any separate substances are included under enscommune, it is the angels. For unlike God, angels are included under a genus

22 : I llud enim quod primo acquiri tur ab intellectu est ens, et id in quo non invenitur ratio entisnon est capabile ab intellectu ; unde, cum causa prima sit supra ens, consequens est quod causaprima sit supra res intelligibiles sempiternas. Causa autem prima, secundum PLATONICOSquidem,est supra ens in quantum essentia boni tatis et unitatis, quae est causa prima, excedit etiam ipsumens separatum, sicut supra dictum est. Sed secundum rei veri tatem causa prima est supra ens inquantum est ipsum esse infinitum, ens autem dicitur id quod finite participat esse, et hoc estproportionatum intellectui nostro cuius obiectum est quod quid est ut dicitur inIII De anima .

40Cf. ST, I , q. 7, a 1, ad 3, ed. cit., vol. I V, p. 72. For other texts where Thomas describes Godas beyond being (super or supra ens), see Scriptum super Sententiis II (hereafterIn II Sent .), d.2, q. 1 a. 1 ad 1, ed. P. M ANDONNET , Lethielleux, Pari s 1929, vol. I I , p. 64 ;In l ibrum beati Dionysii

De divinis nominibus expositio (hereafter In De div. nom.), c. XIII, lect. 3, n. 994, ed. C. P ERAMarietti, Turin-Rome1950, p. 369.

41 See, e.g., the Four th Way in ST, I , q. 2, a. 3, ed. cit., vol. I V, p. 32 ;In De Trin ., q. 5, a. 4,ed. ci t., pp. 153, lin. 131 - 154, l in. 143.

42 Quaestiones disputatae de veritate (hereafter,De ver.), q. 10, a. 11, ad 10, in SAN CTITHO MAEDE A QUINOOpera Omnia, vol. 22.2, Commissio L eonina, Rome 1972, pp. 337-338, li n. 306-316.See alsoIn V De d iv. nom.,lect. 2, nn. 655-660, ed. cit., pp. 244-245. There, Thomas shows thatGod transcends esse commune. Since esse commune is equal in scope to enscommune , hisarguments in this text also imply that God transcends enscommune .

43 Regarding Thomass understanding of the meaning of sempiternal in theLiber de causis,seeIn Lib. de caus .,Prop. 11, ed. cit., p. 73, lin. 2-8.


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because their essence is distinct from their act of existing (esse). And inasmuchas angels subsist in their participated acts of existing, the genus under which

they are included is substance44

. Unlike God, moreover, angels are createdbeings. As such, they must be included under ens commune. If this is true,whatever pertains to the nature of being in general also pertains to angelsinasmuch as they are beings. And, in fact, when Thomas considers theprinciples of act and potency in the Summa contra Gentiles(hereafter SCG)he observes, Matter and form divide natural substance, but potency and actdivideens commune. And for this reason, whatever follows potency and act assuch is common to material substancesand to created immaterial substances such as to receive and to be received, to perfect and to be perfected 45 .

And yet, as we have seen in his commentary on theDe Trinitate, Thomas

expli citly says of God and the angels that such divine things are not treatedby philosophers except insofar as they are the principles of all things46 . Thisstrong statement would seem to indicate that metaphysics treats angels only

44SeeIn L ib. de caus .,Prop. 7, ed. cit., p. 49, lin. 23-28 ;In De Trin.,q. 6, a. 3, ed. cit., p. 168,lin.133-136 ; Quaestio disputata De spiritualibus creatures (hereafterDe spir . creat .), a. 1, ad 10,in SANCT ITHO MA EDE AQUINOOpera Omnia, vol. 24.2, Commissio Leonina - Vri n, Rome -Par is 2000,pp. 17-18, lin. 574-581 ; ibid., a. 5, p. 61, lin. 195-214 ; ST, I , q. 88, a. 2, ad 4, ed. cit., vol. V I , p.367. Regarding how Thomas thinks genus and species are to be taken in separate substances, seeSCG, II, c. 95, ed. cit., vol. XIII, pp. 568-569. Thomas explains that sensible substances and

created immaterial substances fall under the same genus according to the logical order sincethey are grasped according to the same intelligible intention. Nevertheless, the two are notincluded under the same genus according to the order of reality since they differ in their degreesof actuali ty. Thus, the philosopher of nature and the metaphysici an, who consider essences asthey exist i n reali ty, treat bodies and angels as fal ling under di fferent genera. SeeIn De Trin .,q. 6, a. 3, ed. cit., p. 168, lin. 133-153 ;De spir . creat. , a. 2, ad 16, ed. cit., p. 32, li n. 456-471 ;Quaestio disputata De anima (hereafter Quaes. disp. de an.), q. 7, ad 17, in SAN CT I THO MA EDE

AQUINOOpera Omnia, vol. 24.1, Commissio Leonina - Vri n, Rome -Pari s 1996, p. 62, lin. 475-489 ;ST, I , q. 88, a. 2, ad 4, ed. cit., vol. V I , p. 367. Despite this observation, T homas stil l presentsthe metaphysician as treating both bodies and angels as substances (see n. 34 above). I do nottake him to mean that the metaphysician treats the two as substances in equivocal ways. As

Thomas explains, some things treated by the logician as univocal according to the logical orderare in fact analogical according to the order of reality (In I Sent ., d. 19, q. 5, a. 2, ad 1 ed. cit.,p. 492). This is the case, I would argue, with respect to the term substance when predicated ofboth bodies and angels : the logician treats the two as substances in a univocal way, whereas themetaphysician treats them as substances in analogical ways.

45 SCG, I I , c. 54, ed. cit., vol. X I I I , p. 392 : Unde materia et forma dividunt substantiamnaturalem : potentia autem et actus dividunt ens commune. E t propter hoc quaecumque quidemconsequuntur potentiam et actum inquantum huiusmodi, sunt communia substantii s materialibuset immaterialibus creatis : sicut recipere et recipi , perf icere et perf ic i . Emphasis added intranslation. Cf .In IX Meta,lect. 1, n. 1171, ed. cit., p. 301. For di scussion of the quoted passage,see N. KRETZMANN, The Metaphysics of Creation: Aquinass Natural Theology in Summa contragentilesII,Oxford University Press, New York 2001, p. 267.

46In De Trin., q. 5, a. 4, ed. cit., p. 154, l in. 157-159. For Latin, see above, n. 19.


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as principles of its subject matter and not as included under it. Given therelationship between angels andenscommunethat we have already identif ied,

Thomas appears to be contradicting himself . One possible explanation forthis seeming inconsistency is that the above quoted statement is merely ayouthful one that he abandons in his later wri tings: in the later commentaryon the Metaphysics, we do not find such exclusionary language. Thisexplanation, however, does not account for the seeming internal inconsistencywithin the commentary on theDe Trinitateitself.For in this very same work

Thomas not only emphasizes that separate substances are treated inmetaphysics solely as principles, but he also identifies the subject matter ofmetaphysics as the negatively immaterialenscommune, which is sometimesfound apart from matter and sometimes not47 . Thus, even if we consider this

work alone, he seems to imply there that a divine being such as an angel bothis and is not included under the subject matter of metaphysics.

I would argue that a better explanation for this seeming inconsistency isthat the above quoted statement about divine things needs to be read in aquali fied sense. When Thomas says that such divine things are not treated byphilosophers except insofar as they are the principles of all things, I take himto be referring to the divine things inasmuch as they are divine in otherwords, inasmuch as they areseparatesubstances.When they are considered assuch, they can only be treated by the metaphysician as causal principles. Thesame separate substances, however, can also be considered in another respect,namely, simply inasmuch as they are substances. This twofold manner in whichI contend the separate substances can be studied is in fact identified by Thomashimself in his commentary on the Metaphysics. In Book VI I of Aristotles ownwork, the Stagirite observes that it is for the sake of separate substances thathe is trying to define sensible substances (1037a10-20). In commenting on thispassage, Thomas goes beyond the literal tenor of the text to explain howmetaphysics studies both sensible and separate substances :

In thi s science we attempt to study sensible substances for the sake of these,

that is, for the sake of immateri al substances, since the investigation concerningsensible and material substances belongs in a certain way to physics, which isnot Fi rst Phi losophy but second, as was said in Book IV. I ndeed, Fi rst Phi losophyis about the first substances, which are immaterial substances. It examinesthese not only inasmuch as they are substances, but inasmuch as they aresuchsubstances, namely, inasmuch [as they are] immaterial. It does not, however,examine sensible substances inasmuch as they are such substances, butinasmuch as they are substances, or also beings, or inasmuch as we are led by

47 SeeIn De Trin .,q. 5, a. 4, ed. cit., p. 154, lin. 175-198.


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them to an understanding of immateri al substances. Conversely, the physiciststudies materi al substances, not inasmuch as they are substances, but inasmuchas [they are] materi al and have in them a principle of motion 48 .

According to Thomas, then, metaphysics considers the separate substancesin two respects : as immaterial and as substances. As we have seen, i t is whenthe separate substances are considered as immaterial that they are treated asthe principles ofens commune. In his Commentary on theDe Trinitate,Thomasexplains that the principles of all beings must be most perfect and supremelyin act, with no potency or the least potency possible. This is why he concludesthat the first principles must be immaterial49. And, I would argue, this is whyhe states in the same work that the philosophers do not study divine things

except insofar as they are principles; for inasmuch as those beings are divine(that is, immaterial), they can only be studied as principles. When the separatesubstances are considered as substances, however, they are not treated asprinciples but simply as beings. This is because it is not of the nature ofsubstancesassubstances to be the first principles of all beings50 .

This distinction that Thomas draws, however, should not be read assuggesting thatallimmaterial substances can be studied in these two respects.As we have seen, he holds that God is not i ncluded under any genus, even thegenus substance : metaphysics does not examine God as a substance but,rather, only as the principle of substances51. Thus, it is onlycreatedimmaterial

substances that metaphysics examines in these two respects. In short, theseparate substances to which Thomas is referring in this text are the angels.Insofar as they are immaterial, they are treated in metaphysics as principlesof its subject matter, enscommune. But insofar as they are substances orbeings, they are treated as objects included under that subject matter.

48In VII Meta.,lect. 11, n. 1526, ed. cit., p. 369 : In hac enim scientia tentamus determinarede substantiis sensibil ibus huius gratia, idest propter substantias immateriales, quia speculatiocirca substantias sensibiles et materiales quodammodo pertinet ad physicam, quae non estprima philosophia, sed secunda, sicut in quarto habitum est. Prima enim philosophia est deprimis substantii s quae sunt substantiae immateriales, de quibus speculatur non solum inquantumsunt substantiae, sed inquantum substantiae tales, inquantum scilicet immateriales. Desensibi li bus vero substantii s non speculatur inquantum sunt tales substantiae, sed inquantumsunt substantiae, aut etiam entia, vel inquantum per eas manuducimur in cognitionemsubstantiarum immateri alium. Physicus vero e converso determinat de substantiis materialibus,non inquantum sunt substantiae, sed inquantum materiales et habentes in se principiummotus . Emphasis added in translation.

49 See pp. 350-351 above.50 If it were, then even material substances would be first principles inasmuch they are

substances, which Thomas does not hold.51 See pp. 358-359 above.


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Returning to our two major questions raised above, we now see the answerto the first, which had asked whether Thomas considers angels to be included

under the subject matter of metaphysics. Still, he does also treat them asprinciples of this subject matter, which brings us to the second majorquestion, namely, how is it possible for the angels to be included under asubject matter of which they are principles? It would seem that these tworoles are mutually contradictory, for if the angels are indeed causes of ens

commune, then it appears that they are somehow causes of themselves. AsThomas notes, however, nothing can be the (effi cient) cause of its veryexistence52 . How, then, are we to resolve these seemingly contradictory rolesof the angels in his metaphysical system ?

One solution is that we could read his reference to the divine status of the

angels as a nuanced way of referring simply to God whi le still accommodatingthe Aristotelian tradition. This reading is suggested by J oseph Owens. Writingon Aquinass role as an Aristotelian commentator, Owens acknowledges thedual status Thomas ascribes to the angels wi thin his metaphysical system. Ascreatures, Owens explains, the angels are included under common being (ens

commune) and are part of the subject matter of metaphysics, but as principlesthey are not part of that subject. He presents Thomass distinction betweenthese two roles as follows:

When the separate intelli gences are contrasted wi th common being as itscause or principle, then, they are viewed as coalescing in nature with theChri stian God. I n the Aristotelian tradition they were called divine, and fromthis viewpoint would for a Christian have to coincide with the one supremeGod. When on the other hand they are regarded as angels and accordingly ascreatures, they are all composed of actuali ty and potentiality, and in thi s wayexhibit unity and multiplici ty53 .

Owens appears to treat Thomass inclusion of the angels among thecommon and universal causes ofenscommuneas simply an acknowledgementof an Aristotelian tradition54 . Following this reading, when Thomas treats the

52 See, e.g.,ST, I , q. 2, a. 3,ed. cit., vol. IV, p. 32 ;In III Meta., lect. 8, n. 441, ed. cit., p. 123.53J . OWENS,Aquinas as Aristotel ian Commentator, in St. Thomas Aquinas on the Existence of

God: Collected Papers of Joseph Owens, C.Ss.R., State University of New York Press, Albany1980, p. 234, n. 19. Within this note, he references a prior note in which he offers a somewhatdif ferent and even confli cting interpretation. There he observes that apparently Aquinasexperienced little di ffi culty i n seeing the Aristotelian separate substances coalesce in the oneChristian God, or on the contrary in regarding them as God and angels together, or i n speakingof them as God and the intelligences according to the Neoplatonic tradition as found in theArabians (ibid., p. 234, n. 17).

54

Ibid., pp. 4-5.


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angels as divine, he is no longer treating them as angels ; indeed, Owensseems to suggest that he is no longer treating themat al l. I f Owens is correct,

the reference to the angels as divine is in fact simply a reference to God sincea Christian such as Thomas supposedly considers only God to be divine. Inlight of this reading, there is no contradiction in Thomass account of theangels relation to the subject matter of metaphysics : angels are only includedunderenscommuneand are not its cause.

Owenss reading would indeed resolve our problem, but I would argue that itis not borne out by the text. Nowhere does Thomas indicate that the angelssomehow coalesce or coincide with the divine nature55. To the contrary, hisexplicit language indicates that he considers there to be a number of separatesubstances as the causes ofenscommune. As we saw in his commentary on the

De Trinitate,moreover, Thomas explicitly identifies the angels as such causes,noting, in the divine science that the philosophers teach, the angels (which theycall Intelligences) are considered from the same perspective as the first cause,which is God, insofar as they are also secondary principles of things 56. In thisquotation, we not only see a clear affi rmation of the role of angels as principlesof the subject matter of metaphysics, but also intimations of a possible solutionto our problem regarding the relation of angels to that subject. According to

Thomas, they aresecondaryprinciples of things. In other words, even thoughthey are principles ofenscommune, they are not so in the same way as is God.

To answer our second major question, then (namely, how angels can be includedunder a subject matter of which they are causes), we need to consider what thecausality of these secondary principles ofenscommuneentails57.

I I I

As we have just seen, Thomas considers the first cause of all beings to beGod. He does not, however, consider ens commune simply to beaneffect ofGod ; as Thomas makes clear, i t is in fact the proper effect (proprius effectus)

55 Indeed, Owens himself does not provide any citations to support this reading.56 See above, p. 354.In De Trin .,q. 5, a. 4, ad 3, ed. cit., p. 155, li n. 239-250. For the Latin,

see n. 25 above.57 Zimmerman, unlike Owens, emphasizes the role of the angels as secondary principles.

Nevertheless, he stil l reaches a conclusion similar to Owens. He does not not speak of the angelsas coalescing in nature with God, but instead explains that das Verhltnis der abgetrenntenSubstanzen zum Subjekt der M etaphysik ein wesentli ch anderes ist als das Verhltnis Gottes zudiesem Subjekt. Die abgetrennten Substanzen erweisen sich nmli ch als Zweitursachen, und alssolche gehren sie zum Seienden im allgemeinen. Sie sind nicht Ursachen des Seienden als

solchen, sondern es ergibt sich, da sie als ein Teil des Seienden bezeichnet werden mssen. Gottal leine ist Ursache des Seienden im al lgemeinen (ZIMMERMANN, Ontologie oder Metaphysik? cit.,pp. 217-218). E mphasis added. Cf . ibid., p. 222.


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of effect of God58 . This is becauseesse, the principle in every finite being bywhich it is a being, is itself Gods proper effect. As he explains in Summa

theologiae(hereafter ST), I, q. 45, a. 5, those effects that are more universalare reduced to causes that are more universal. Since esseitself is the mostuniversal effect, it must therefore be the proper effect of the first and mostuniversal cause, which is God59 . If we consider the relationship between ensand essein terms of Thomass doctrine of participation, it becomes clearerwhyenscommune, also, must be Gods proper effect. In his commentary onBoethiuss De hebdomadibus,Thomas explains that ensparticipates in esse,although not in the way the less common participates in the more common.

The reason is thatensandesseare both most common (communissimum). Inother words, they are equal in scope.Ens, however, is concrete, whereasesse

is abstract. Hence, Thomas concludes, the former participates in the latter asthe concrete participates in the abstract60 . It is because esse itself is Godsproper effect, therefore, thatenscommuneis as well , for inasmuch as he is thecause of the former, he is the cause of the latter.

From his earliest writings, Thomas holds that to causeessein an absolute way(absolute) or simply (simpliciter) is nothing less than to create since to create isto make something out of nothing, that is to say, out of absolute nonbeing (non

ens)61 . Only God, however, can create. Among the philosophical reasons thatThomas commonly gives to support this position is that the distance betweenbeing and absolute nonbeing is infinite; hence an infinite power is required tobring something into existence from absolute nonbeing. Since only God isinfinite, Thomas concludes that only God has the power to create62.

Thomas acknowledges that some authors who have agreed with thisconclusion (such as Avicenna and Peter Lombard) held that Gods creativepower can nevertheless be communicated to a created being, namely, to anIntelligence or angel. In this way, a created agent could act as an instrumentalcause of creation. Thomas, however, rejects this position as well. As heexplains in ST, I, q. 45, a. 5, a secondary instrumental cause participates inthe action of a superior cause, but only by means of something proper to itself

58See,e.g. , ST,I -I I , q. 66, a. 5, ad 4, ed. cit., vol. VI , p. 436.59 ST, I, q. 45, a. 5, ed. cit., vol. IV, p. 469.60Expositio libri Boet ii De ebdomadibus, c. 2, in SAN CT ITHO MA EDE AQUINOOpera Omnia, vol.

50, Commissio Leonina - Vrin, Rome - Paris 1992, p. 271, lin. 95-113.61In I I Sent., d. 1, q. 1, a. 2, ed. cit., pp. 16-20 ; SCG, I I , c. 16, ed. cit., vol. X I I I , pp. 299-300 ;

ST, I, q. 45, a. 1, ed. cit., vol. IV, pp. 464-465.62Scriptum super Sententiis IV (hereafterIn IV Sent.), ed. M. F. M OOS, L ethielleux, Pari s 1947,

d. 5, q. 1, a. 3, ad 5, vol. I V, pp. 210-211 ; SCG, I I , c. 21, ed. cit., vol. X I I I , p. 313 ; ST, I , q. 45, a. 5,ad 3, ed. cit., vol. I V, p. 469;De pot.,q. 3, a. 4, ed. cit., pp. 46-47; Compendium theologiae, c. 70, inSANCTITHOMAEDEAQUINOOpera Omnia, vol. 42, Commissio Leonina, Rome 1979, p. 103, lin. 1-14.


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through which it disposes the effect of the principal agent. Thus, a saw cutswood by the form that is proper to itself, disposing the wood to the form of a

stool, which is the proper effect of the principal agent. I f an instrument suchas a saw did not act according to anything proper to itself, then it would notbe able to dispose an effect for the principal agent and thus would bepointless. All effects other than that of creation, however, presuppose theproper effect of Gods creating because that effect is essetaken absolutely ;thus, Gods creative act presupposes nothing on which an instrument couldact dispositively. And so, Thomas concludes, it is impossible for createdbeings (including angels) to create, even as instrumental causes63 .

In SCG, I I , c. 21, Thomas offers several other arguments in support of theconclusion that only God can create. In one of these, he clarifies the different

ways in which God and creatures are causes of beings. Thomas explains thateffects correspond proportionately to their causes; thus effects in actcorrespond to actual causes and effects in potency to potential causes. Similarly,particular effects correspond to particular causes and universal effects touniversal causes. Butesseis the first effect, which is clear given its universali ty.

Therefore, the proper cause of esseis the first and universal agent, namely,God. Thomas then explains that other agents are not the cause of esseabsolutely (causa essendi simpliciter), but are only the cause of being this(causa essendi hoc), such as being man or being whi te. By contrast,essetakenabsolutely (essesimpliciter) is caused through creation, which presupposesnothing since something cannot preexist that is outside of being taken absolutely

63 ST, I, q. 45, a. 5, ad 3, ed. cit., vol. IV, p. 469. According to Avicenna, God immediatelycreates the First Intelligence, which in turn creates three things : the Second Intelligence, thebody of the outermost heavenly sphere, and the soul of that sphere. The Second I ntelligence, inturn, creates the Third Intelligence, the body of the next heavenly sphere, and its soul. Thismediated creation continues until the Tenth Intelligence (or Active Intellect) which does notcreate another intelligence but instead creates the elements that constitute the sublunar world,together with the forms found in nature (hence, in Latin this last intellect is referred to as the

dator formarum). Avicenna holds, moreover, that this entire chain of creative causality occurs

necessari ly. F or his account of creation through secondary causes, see his Philosophia prima, BkIX, c. 4 inAvicenna Latinus : Liber de Philosophia Prima sive Scientia Divina V-X,ed. S. VAN RI E T,Peeters - Br il l, L ouvain-L eiden 1980, pp. 481-484. Thomas reads Peter L ombard, by contrast,as holding that although God creates everything immediately and freely, it would have beenmetaphysical ly possible for him to share this creative act with creatures as instrumental causes.Thomas argues against this possibi li ty in his later works, however in his early Commentary onthe Sentences,he is more open to it. SeeIn I I Sent ., d. 1, q. 1, a. 3, ed. cit., pp. 21-22;In IV Sent .,d. 5, q. 1, a. 3, ad 5, ed. cit., pp. 210-211. F or other texts where Thomas rejects the possibi li tyof instrumental creative causes, see the texts cited in n. 62 above. For his expli cit rejections ofangels as instrumental creative causes, see, e.g.,In II Sent ., d. 1, q. 1, a. 3, ad 1, ed. cit., p. 22 ;

De pot., q. 3, a. 4, ad 12, ed. cit., p. 48 ; ST, I , q. 65, a. 3, ed. cit., vol. V , pp. 150-151.


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(enssimpliciter). Agents other than God instead cause this being or suchbeing (hoc ens vel tale) since it is out of a preexistent being that this being or

such being is made64

. Indeed, from the time of Thomass earliest writings heidentifies God as the cause of being (causa essendi), but created agents aswhat he terms the cause of becoming (causa fiendi or fieri)65 .

These observations regarding thecausa essendi have led some scholars toconclude that Thomas considers God to be the only cause of essein createdbeings66. I f their reading is correct, God would be the only principle of beings

quabeings and, hence, the only cause of ens commune. This reading thusappears to exclude the angels entirely as causes of the subject matter ofmetaphysics. And yet, Thomas still treats them as such causes, even whenaffirming God as the onlycausa essendi.As we have seen, in his commentary

on the De Trinitate Thomas suggests that there is only a single principle ofesse. Nevertheless in the same sentence he indicates that there are manyprinciples of all beings67 . Moreover, in that work he also observes that inmetaphysics the angels are considered from the same perspective as the fi rstcause, which is God, insofar as they are also secondary principles of things68 .In other words, the angels, li ke God, are principles ofenscommune, althoughin a secondary way. Still, we have also seen Thomas conclude that therecannot be any instrumental or secondary causes of creation. We might ask,then, how it is possible for there to be secondary principles ofenscommune ?

An answer is suggested in a recent piece by J ohn F . Wippel entitledCreatures as Causes ofEsse. In this piece Wippel shows that even thoughcreated agents cannot produceessefrom nothingness, either as principal oras instrumental causes, they can produce it in another respect, namely, in the

64SCG, I I , c. 21, ed. cit., vol. X II I, p. 313. See KRETZMANN, Metaphysics of Creation cit.,pp. 99-100, 116.65Thomas gets thi s distinction f rom Avicenna. See AVICENNA, Philosophia primaIX, c. 4, in

Avicenna Latinus : Liber de Philosophia Prima sive Scientia Divina V-X, ed. S. VANR I ET, Peeters -Brill, Louvain - Leiden 1980, pp. 481-484. For Thomass use of this distinction, see In I Sent., d.7, q. 1, a. 1, ad 3, ed. cit., pp. 177-178 ;De ver.,q. 5, a. 8, ad 8, ed. cit., p. 160, lin. 324-339 ;De pot.,

q. 5, a. 1, pp. 131-132 ; ST, I , q. 104, a. 1, ed. cit., vol. V, pp. 463-464. On his use of thi s distinction,see C. FABRO, Participation et causalit selon s. Thomas dAquin , Publications Universitaires,Louvain 1961, pp. 340 ff. ; F. X . M EEHAN, Efficient Causality in Aris totle and St . Thomas , TheCatholic University of America Press, Washington, D.C. 1940, pp. 317 ff.

66See, e.g., . G ILSON, The Christian Philosophy of St. Thomas Aquinas, trans. L. K . Shook, C.S.B.,Random House, New York 1956 ; reprint, University of Notre Dame Press, Notre Dame, Indiana1994, p. 123 (page citations are to the reprint edition) ; H. RENARD, Philosophy of God, Bruce,Milwaukee 1949, p. 20 ; J . ANDERSON, The Cause of Being, Herder, St. Louis 1952, pp. 20, 28-30.

67See pp. 350-351 above. SeeIn De Trin .,q. 5, a. 4, ed. cit., pp. 153, lin. 131 - 154, lin. 143.For the Latin, see n. 15 above.

68In De Trin .,q. 5, a. 4, ad 3, ed. cit., p. 155, lin. 239-250. For the Latin, see n. 25 above.


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generation of material substances. He reminds us of Thomass oft stateddictum that form gives being (forma dat esse). By this dictum, Thomas does

not mean to suggest that form efficiently causes theesseof a being, but ratherthat it formally causes esse. A substance, for example, exists substantiallybecause of its substantial form69 . Natural substances, however, come intobeing because their forms are educed from matter by natural agents70 . Sinceform gives being (esse), Wippel concludes that created agents must in somesense be causes ofesseeven in their role as causes of becoming (causae fiendi).

This is not to say that they are the sole cause ofesseor that they cause essetaken absolutely. As Thomas explains in SCG, III, c. 66, esse is indeed thecommon effect of everyagent (for every agent makes something actually tobe), but created agents produce this effect only because they are ordered

under the First Agent and act with its power 71 . Wippel thus concludes,

From this it fol lows that, for Thomas, whenever a new substance is efficientlycaused by a natural or created agent, that agents causation applies both to theact of being itself (esse) of the new substance and to a particular determinationofesse as realized in that substance. Causation of the parti cular determination(this or that kind of form) is owing to the created efficient cause insofar as itoperates by its own inherent power as a principal cause. Causation of the actof being itself (esse) is assigned to i t as an instrumental cause acting with thepower of God and to God himself as the principal cause of the same. From thi s

it fol lows that one should not maintain that Thomas denies that created causescan efficiently cause the act of existing or the act of being, at least in theprocess of bringing new substances into being 72 .

In short, created agents can be instrumental causes of esse not asprinciples of creation, but as principles of generation. Thus, they can beconsidered causes of essein their very role as causae fiendi . What is more

69J . F . W IPPEL , Thomas Aquinas on Creatures as CausesofE sse, in Metaphysical Themes inThomas Aquinas II,The Cathol ic Universi ty of America Press, Washington, D.C. 2007, pp. 175-

179, 192. Regarding the application of this dictum to substantial form, seeIn I Sent ., d. 17, a.1, a. 1, ed. cit., p. 393 ; SCG, I I , c. 68, ed. cit., vol. X I I I , p. 440. For other applications, see, e.g.,

In I Sent., d. 24, q. 1, a. 3, ed. cit., p. 582 ;De ver.,q. 29, a. 8, ad 8, ed. cit., p. 871, l in. 312-315 ;Quaes. disp. de an.,q. 10, ad 2,ed. cit., p. 92, lin. 286-293 ;De ente,c. 4, ed. cit., p. 376, lin. 45-46; De principiis naturae, c. 1, in SAN CTI THOMA EDE AQUINO Opera Omnia, vol. 43, CommissioLeonina, Rome 1976, p. 39, li n. 32-35 ;In V Meta.,lect. 2, n. 775, ed. ci t., p. 213. For more textsand for discussion about this dictum, see F ABRO, Participation et causalit cit.,pp. 349-362.

70 Regarding Thomass doctrine of natural causality and the eduction of form, see De pot.,q. 3, a. 8, ed. cit., p. 62.

71 SCG, III, c. 66, ed. cit., vol. XIV, p. 188.72 WIPPEL , Creatures as Causes of Esse cit., p. 193.


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significant, however, is that Thomas eventually comes to consider at leastsome created agents to merit the namecausa essendi. As Wippel shows, this

new stance results from a clarif ication of terminology that Thomas offers inthe Prima pars of the Summa theologiae (1265-1268). In q. 104, aa. 1-2, hediscusses the distinction between a causa fiendi and a causa essendiin thecontext of examining the preservation (conservatio) of created beings. Giventhe importance of these articles for our consideration of angelic causality, itis worth examining them here in some detail.

In article 1 Thomas addresses whether creatures need to be preserved byGod. He begins by noting that we must affirm, according to both faith andreason, that creatures do indeed need to be preserved by God. He thenproceeds to offer philosophical reasoning in support of this conclusion,

noting that something can be preserved in one of two ways: either indirectlyand per accidens, or directly and per se. The sort of preservation that isindi rect andper accidensoccurs when one thing preserves another by removingsome cause of corruption. Thus, for example, someone who protects a childfrom falling into a fire is said to preserve the child according to this first typeof preservation. And in this sense, Thomas concludes, God is said to preservesome things but not everything since certain things are not subject tocorruption. As a result, they do not require the removal of any corruptiveinfluences for them to be preserved in existence73 . In contrast to this type ofpreservation, the sort that is direct andper seoccurs when something dependsupon a cause for its preservation in such a way that without that cause, thething would be unable to exist. And in this way, Thomas concludes, allcreatures depend upon a divine preservation because the existence (esse) ofevery creature is from God. Hence, without the work of the divine powerpreserving creatures in existence, they could not subsist even for a moment,but would instead be reduced to nothing74 .

Thomas then offers further evidence in support of this conclusion. As heexplains, every effect depends upon its cause insofar as that cause is its cause.Some agents, however, are only causes of their effects coming intobeing

(secundum fieri) but not as regards its being (secundum esse). We find this inthe case of both arti ficial things and natural things. Giving an example drawnfrom art, Thomas notes that a builder causes a house to come into being, buthe does not di rectly cause its very being (esse). Rather, the being of a housedepends upon its form, which consists in the composition and order that

73 Although Thomas does not identify here any such incorruptible beings, angels would bean example since they do not possess an intrinsic principle of corruption, viz., matter.

74 ST, I, q. 104, a. 1, ed. cit., vol. V, pp. 463-464.


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follows from the natural capacity (naturalem virtutem) of certain things.Clarifying what he means by natural capacity, Thomas notes that a cook

cooks food using a certain natural active capacity, namely, that of fire. So,too, the bui lder bui lds a house using cement, stones, and timbers : materialsthat, given their natural capacity, are appropriate both to the compositionand order of a house as well as to its preservation. Hence, Thomas concludes,the being of a house depends upon the nature of these things just as its cominginto being depends upon the action of the builder75 .

In this example of the house, we find a distinction drawn between twotypes of causes based upon the way in which the effect depends on them. Thebuilder is merely acausa fiendibecause the house does not depend upon himin order to remain in existence. Hence, he is not a direct andper secause of

its preservation. Implicit in this discussion is the conclusion that no causafiendi preserves its effect in that way. By contrast, the form and matter of thehouse arecausae essendi because the house does in fact depend upon them asdirect andper secauses of its preservation : should either intrinsic principlebe removed, the house would cease to exist. I n this example, however, Thomashas only provided us with instances ofcausae essendiin the realm of art andonly as regards material and formal causality. But he next notes that theseconsiderations also apply to natural things, and here he turns hi s attention toefficient causality. If some agent is not the cause of form as such (formaeinquantum huiusmodi), Thomas explains, it will not be the per se cause ofbeing (esse) that results from such a form ; rather, i t wi ll only be the cause ofthe effects coming into being. With this observation, he reveals the sort ofefficient cause that is capable of acting as acausa essendi, namely, one thatcan cause form as such. He then proceeds to identi fy what sort of agent cancause form in this way76 .

When two things belong to the same species, Thomas explains, one cannotbe the per se cause of the others form inasmuch as it is such a form ( talis

forma) ; for i f that agent could do so, it would then also be the cause of i ts ownform since the agent would have the same nature as its effect. I t can, however,

be the cause of such form inasmuch as the form is in matter, or, to be moreprecise, inasmuch as this matter acquires this form. This is the way mangenerates man, and fire generates fire. And such a cause is a cause ofbecoming (causa secundum fieri). Having noted this, Thomas explains thatwhenever an effect receives the likeness (impressio) of the agent according tothe same nature (ratio) as it is found in that agent, then the effect depends

75Ibid .76Ibid .


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upon the agent for its coming into being, but not for its very being. This sortof agent is what he elsewhere refers to as a univocal cause. In contrast to the

effects of such an agent, other effects do not receive the agents likenessaccording to the same nature. We find thi s to be the case with all those agentsthat make things according to a species that is not like their own. Thomasoffers an example from the physics of his time, noting that the heavenly bodiesare the causes of the generation of terrestrial bodies that are unlike them inspecies. Such agents he elsewhere terms equivocal causes or analogicalcauses. And he explains here that this sort of agent can be the cause of formnot only as it is received in mater, but of form as such. Therefore, Thomasconcludes, it is not only acausa fiendi but also acausa essendi77 .

Having drawn all of these distinctions, Thomas proceeds to show that God

is a causa essendi upon which all beings continuously depend for theirpreservation as long as they exist. For our purposes, however, it is sufficientto note the principal characteristics that he ascribes to acausa essendi in thistext.1) First, Thomas presents it as the sort of cause upon which an effectdepends directly and per se for its preservation. In this respect, he hasextended the notion of acausa essendi from his treatment of i t in earl ier texts,where he had identi fied it simply as an agent that producesesse in an absoluteway78 . 2) Second, in considering natural effects, Thomas concludes that a

causa essendi is the cause of the effects form as such, as well as its formcoming to be in matter. I n short, he concludes that such an agent is a universalcause, causing the very nature of the effect. I t is in i ts role as a universal cause,then, that an agentpreserves its effect directly and per se, since the effectdepends (in part) upon its form as such to remain in existence. 3) Finally,

Thomas identifies a causa essendi as belonging to a higher species than itseffect ; in other words, he presents such an agent as an analogical cause. I t isthis third and final characteristic that accounts for the second and first,namely, for the agents abili ty to be a universal cause and to preserve its effectin existence. What is perhaps of most interest to us, however, is the examplethat Thomas gives of the heavenly bodies. Al though hi s example stems from

77Ibid ., ed. cit., p. 5, l in. 464. Regarding the nature of univocal causali ty, see, e.g.,In I Sent.,d. 35, q. 1, a. 4, ad 1, ed. cit., p. 820 ;De pot.,q. 7, a. 5, ed. cit., p. 198 ; ST, I , q. 13, a. 5, ad 1,ed. cit., vol. IV , p. 147 ; Sententia super Physicam (hereafterIn Phys.),I I , c. 7, lect. 11, in SAN CTITHOMA EDEAQUINOOpera Omnia, vol. 2, Ex typographia polyglotta, Rome 1884, p. 88. Regardingthe nature of equivocal or analogical causality, see, e.g., SCG, I , c. 29, ed. cit., vol. X I I I , p. 89 ;

De ver. , q. 10, a. 13, ad 3, ed. cit., p. 345, li n. 158-170 ; ST, I , q. 4, a. 2, ed. cit., vol. I V, pp. 51-52. For some discussion about both modes of causali ty, see FABRO, Participation et causalit, pp.338 ff. ; WIPPEL , Metaphysical Thoughtcit., pp. 517-518 ; MEEHAN ,Efficient Causality cit.,p. 320.

78 Regarding Thomass developed notion of the causa essendi in this text, see FABRO,Participation et causalitcit.,pp. 377-378 ; WIPPEL , Creatures as Causes ofEsse cit., pp. 189, 193.


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an outdated physics, it nevertheless reveals his conclusion that in a certainrespect, at least some created beings can act as causes of esse.

This conclusion is confi rmed in ST, I , q. 104, a. 2, in which Thomasconsiders whether every creature is preserved by God immediately. H e beginsthe article by reiterating the two ways in which a thing is preserved in being(in esse) by another. In one way, something is preserved indirectly and peraccidens because another thing removes or impedes the action of somecorruptive influence. I n another way, something is preserved directly andper

se because its being (esse) depends upon another as the being of an effectdepends upon a cause. And according to both ways, Thomas tells us, somecreated being is found to be preserved by another. Regarding the fi rst way, itis clear that among corporeal things there are many causes that impede the

actions of corruptive influences. He offers as but one example the fact thatsalt impedes meat from rotting79 .

Regarding the second way in which one thing is preserved by another,Thomas states that there are also found some effects that depend upon certaincreatures for their being (esse). Now, when there are many causes existing inan ordered series, the effect depends fi rst and foremost (principaliter) upon thefirst cause and secondarily on all of the intermediary causes. Therefore the firstdirect andper secause of an effects preservation is its principal cause. All ofthe intermediaries are secondary causes of the preservation, with the higherones that are closer to the first cause acting as causes more so than the lowerones. For this reason, the preservation and permanence of corporeal things isattributed to superior causes (that is, to created secondary causes). As in theprior article, Thomas offers as an example the dependence that natural thingshave on the motion of the heavenly bodies. Thus, he concludes, God preservescertain things in being (esse) through certain intermediate causes80.

In this article, then, we find Thomas concluding that at least some createdbeings can be causes of esse (causae essendi)

Documents

Doolan G., Aquinas on Separate Substances and the Subject Matter of Metaphysics DSTFM (2011)