[article] Thomas Aquinas on Instrumental Creation, the Cosmogonical Fallacy, and the Intelligibility of Nature

Michael W. Tkacz
Gonzaga University
Bernard J. Coughlin S.J.
Professor of Christian Philosophy

In the second book of his commentary on Peter Lombard’s Sententiae, Thomas Aquinas considers three opinions regarding the creation of the material universe through intermediaries.  The first is the opinion of the Neoplatonic emanationists of the School of Baghdad who held that God created the material world through the creative power of intermediate intelligences.  The second position is that of the Parisian masters of theology who denied Islamic emanationism on the grounds that the infinite power required by creation ex nihilo cannot be communicated to a creature.  The final opinion is that of the Lombard himself who denied the actual communication of creative power to intermediaries, but considered it philosophically possible.  While Thomas is in full agreement with the Parisian masters in their complete rejection of emanationism, he nonetheless here expresses sympathy for Lombard’s position on the philosophical, if not doctrinal, possibility of God’s creation of the world through instruments.

In the second book of his commentary on Peter Lombard’s Sententiae, Thomas Aquinas considers three opinions regarding the creation of the material universe through intermediaries.  The first is the opinion of the Neoplatonic emanationists of the School of Baghdad who held that God created the material world through the creative power of intermediate intelligences.  The second position is that of the Parisian masters of theology who denied Islamic emanationism on the grounds that the infinite power required by creation ex nihilo cannot be communicated to a creature.  The final opinion is that of the Lombard himself who denied the actual communication of creative power to intermediaries, but considered it philosophically possible.  While Thomas is in full agreement with the Parisian masters in their complete rejection of emanationism, he nonetheless here expresses sympathy for Lombard’s position on the philosophical, if not doctrinal, possibility of God’s creation of the world through instruments.[1]

Later in his career, however, Thomas changed his mind on this point and denied the philosophical possibility of any use of instruments in the divine act of creation.  He came to understand creation through intermediaries as contrary, not only to the faith, but to reason as well.  In Summa contra Gentiles II and again in Summa theologica Ia, q. 45, Thomas develops a philosophical argument against the Lombardian position based on an analysis of the nature of instrumentality.  Considered as extensions of the Sententiae text, these later texts, along with question 3 of the De potentia Dei, are generally taken to represent Thomas’ mature thoughts on the nature of creation.[2]  Yet, in the preface of his hexaemeron account in the Summa theologica,[3] Thomas sets out an argument against instrumental creation that does not directly appeal to an analysis of instrumentality, focusing instead on issues concerning the creation of material being as such.  The nature of God’s agency and its incompatibility with acting through instruments retains its importance in a proper understanding of creation ex nihilo, but these considerations are now linked with the intelligibility of the material world.  This association of a correct account of creation and divine agency with scientific knowledge of nature represents a significant aspect of Thomas’ later thought on creation.

In all of his discussions of creation, from the Sentences commentary onwards, Thomas’ overarching concern is with correcting what might be called “the Cosmogonical Fallacy,”[4] the notion that creation is some sort of passage from potentiality to actuality or that creation involves something presupposed–essentially the error committed by the Islamic emanationists.  The identification and correction of this error stands as a major contribution to the philosophical understanding of creation ex nihilo as well as a foundation for a theistic account of divine agency. While it is certainly true that Thomas’ instrumentality argument is directed against this fallacy, it is notable that Thomas also holds that this fallacious notion of creation is incompatible with Aristotelian natural philosophy.  Clearing away the Cosmogonical Fallacy is, for Thomas, not only a means of coming to understand creation aright but is also necessary for ensuring the intelligibility of the material universe and the possibility of a natural science.  The task of this study, then, is to set out Thomas’ argument against instrumental or angelic creation from the hexaemeron text of his Summa theologica, indicating its implications for the intelligibility of natural being.  As will be seen, this argument supports the view that Thomas’ rejection of the Cosmogonical Fallacy was not only aimed at providing a proper understanding of the traditional doctrine of creation ex nihilo, but at doing so in a way supportive of Aristotelian natural philosophy as well.[5]

1. The Cosmogonical Fallacy

A frequent and philosophically significant theme in the writings of Thomas Aquinas is the intelligibility of the theistic notion of creation.  As early as his commentary on the Sentences,[6] Thomas unequivocally claims that reason not only demonstrates the fact of creation (an sit), but also what creation is (quid sit) and what distinctive properties belong to it (an sit talis).  Moreover, this insistence on the intelligibility of creation remains a consistent theme throughout his writings, as indicated by the later treatments in the Summa contra Gentiles, the Quaestiones disputatae de potentia Dei, and Summa theologica.  The context of all of these discussions is Thomas’ opposition to an erroneous notion of creation at the foundation of Islamic emanationism.  The confrontation of this error, the Cosmogonical Fallacy, provides the occasion for Thomas’ investigation into the nature and reality of creation.

Concerned to avoid any introduction of plurality into the absolute first cause of the universe, the emanationists argued for creation through a hierarchy of intelligences.  The first cause can only produce the first effect, otherwise a causal diversity would be attributed to the first cause that is incompatible with its absolute unity.  The diversity of creation, therefore, has its origins in the plurality of instruments of creation that, receiving creative power from the first cause, exercise their diverse powers in the creation of others.  The divine act of creation proceeds in atemporal stages such that the first created intelligence is produced directly by God, and this intelligence produces the next, and so on until the beings of the material world are produced.

Attributing this understanding of creation to Avicenna and the author of the Liber de causis,[7] Thomas finds the source of this heretical view in the mistaken notion of creation as a kind of change (mutationis) or becoming (fieri).  In contrast, Thomas points out, God’s creation is said to be ex nihilo in two ways.  First, creation presupposes nothing in the created thing.  God’s creative agency does not require any pre-existing material stuff nor a pre-existing potentiality of any kind.  The attempt to explain creation as the passage from a pre-existing potentiality to the actual production of a new thing confuses natural change with God’s unique act of creation.[8]  Second, creation is ex nihilo because non-being is logically prior to the being of the created thing.  Without God’s creative agency, the creature does not exist and is, therefore, wholly dependent on God.  Creation is, then, a real relation of the created thing to its creator, but not of the creator to the created thing.  This relation is grounded in God’s efficient agency alone which rules out any relatedness on the part of God toward the creature, while preserving the relation of total dependency of the creature on God.  To hold that God is really related to his creation is to confuse natural relations, which are accidental, with the unique relation of absolute dependence of the creature on God, which implies nothing accidental in God.[9]

This fallacious conflation of natural change and creation ex nihilo certainly underlies emanationism.  Were God to have created the material world through the agency of intermediate intelligences to whom God communicates his creative power, then the creative act of the instrumental agent would not be truly ex nihilo for it would depend on the pre-existent potentiality placed in the intermediate agent by God.  Moreover, were God to have used such instruments in creating, he would be accidentally related to them as they proceed in their agency from potential creator to actual creator.  God would therefore be the potential creator of the material world insofar as his creation of the material world would be dependent upon the exercise of the act of creation on the part of the created intermediate intelligence.

Thus, in his discussion of angelic creation, Thomas explicitly accuses the emanationists of the Cosmogonical Fallacy.  Noting that some philosophers have held that created things proceed from God in stages, Thomas strongly contrasts this with the teaching that the material world is created ex nihilo on the grounds that the fundamental production of material creatures results from the act of creation whereby matter itself is produced.[10]  His point is that God’s act of creation by which material creatures in their hylomorphic composition are brought into existence is not the imposition of form upon available matter.  Divine creation is not a kind of development or process because in any process the incompletely developed state is prior to full development.[11]  Yet, argues Thomas, developmental creation is not creation in the relevant sense for:[12]

[divine] creation is the production of something in the whole of its substance presupposing nothing that is uncreated or created by another.  It cannot be admitted, then, that anything is able to create except God alone who is the first cause.

The emanationists, therefore, hold their erroneous view of the origins of the universe because they misunderstand the nature of creation–that is, they commit the Cosmogonical Fallacy.

Thomas associates the emanationists with the Cosmogonical Fallacy in another way as well.  In cataloguing the various ways in which the philosophers have proposed that bodily forms derive from spiritual substances, Thomas mentions Plato of the Timaeus and the Manichean Albigensians along with Avicenna and the other Baghdad emanationists.[13]  Despite the differences among these views, they all, he claims, have a common root.  It is the error of supposing that, when something is generated, it is a new form that comes into being.  Referring to Aristotle, however, Thomas reminds the reader that it is not so much a new form that comes into being, but the hylomorphic composite.  By focusing on the emergence of the new form alone, the philosophers were mislead into overlooking the necessity of the presence of potentiality for form.[14]  As a result, the emanationists consider the initial production of material forms in a way that is cosmogonically fallacious, for, as Thomas points out, [15]

the initial production of bodily creatures is not considered a transition from potentiality to actuality.  For this reason, the bodily forms that came to be possessed by bodies in their initial production are immediately produced by God.

2. The Instrumentality Argument

While the argument offered by the Parisian masters against the emanationists was the infinite power argument, the primary objection offered by Thomas in his later works was based on an analysis of instrumentality.  The masters of theology had argued that no finite cause could take part in the production of an infinite effect, because an effect must be proportionate to its cause.  Yet, the type of causality involved in creation ex nihilo, wherein being is brought forth from absolute non-being is, as it were, the bridging of an infinite gap.  Such infinite causal power cannot be exercised by a finite being.  Thus, creation ex nihilo cannot be accomplished through created, and hence finite, instruments.[16]

Thomas does indeed present this common argument in his later works,[17] but he relies primarily on the instrumentality argument.  The very nature of an instrument shows the impossibility of creation through intermediaries.  The power of an instrumental cause is necessarily connected with the power the instrument possesses as the sort of being it is.  Thus, while an instrument only acts instrumentally when moved by the higher cause of which it is the instrument, its effect can only be achieved through its own natural causal power.  It is this natural causal power of the instrument, of course, that is being employed by the higher cause in moving the instrument to bring about the effect.  When something is accomplished through the use of an instrument, therefore, there is a proportional relation, not only between the operation of the higher cause and its instrument, but also between the natural causal power of the instrument and its instrumental power to bring about the effect.  Indeed, if the instrument cannot act in the way natural to it, then it cannot act instrumentally.  Created instruments, however, naturally act by bringing potentiality into actuality.  Yet, creation ex nihilo does not involve the actualization of any potentiality, for there is nothing in which potentiality can reside.  It follows that creation ex nihilo can never be through instruments.[18]

In the Summa contra Gentiles, Thomas makes this argument the centerpiece of his absolute rejection of the philosophical possibility of creation through instruments, marking the shift from his earlier position in the commentary on Lombard’s Sententiae.  Arguing that every instrumental agent carries out the action of the principle agent only through “action proper and connatural” to the instrument, Thomas shows that such proper action is necessary to the operation of any created instrument.  He confirms this by the example of the digestion of food in animals.  Food is the principle agent in the production of flesh, but it brings about its production through the instrumental agency of digestion.  Were digestion not by nature a process of dissolving and dividing, it could never serve as the agency through which flesh was produced in the process of growth.  This natural agency of the digestive process is prior to the action of the principle agent and is thereby available to the principle for use.  Thomas contrasts this to creation ex nihilo where there is nothing presupposed, because nothing can be prior to the production of being.[19]  To conflate, then, natural production through an instrument and the sort of production that is creation ex nihilo is to commit the Cosmogonical Fallacy.

At Summa theologica Ia, q. 45, a. 5, Thomas provides a similar example from nature.  A material medium, such as air, instrumentally conducts the heat produced by the principle agent, fire, to heat up something.  Air does this by means of a power it naturally has to conduct heat and, therefore, this power is prior to the effect of the heated-up thing–that is, the hot effect is dependent upon the natural heat-conducting capacity of air which air must possess independently of both the primary cause and the effect.  Thomas immediately adds that Avicenna, with his creation through separated intelligences, and Peter Lombard, with his claim of the philosophical possibility of creation through intermediaries, were considering instrumentality in just this way.  Both, however, have overlooked the incompatibility of this necessary feature of instrumental agency with creation ex nihilo, thereby committing the Cosmogonical Fallacy.

Thomas proceeds in the same text to elaborate on the nature of this error, providing his well-known example of an artifact.  The principle agent of the wooden stool is the carpenter who makes use of the instrumental agency of the saw to cut the wood in such a way that it can be pieced together as a stool.  The saw can be used this way, of course, because of its sharp, toothed form which it possesses in virtue of being a saw–that is, in virtue of being the tool it is.  Indeed, were not the saw formed like this, it would not be this instrument nor would it be useful for that task.  Thomas puts it like this: “were [it] not to act according to what is proper to it in itself, it would be employed [by the principle agent] to produce the effect in vain” and the instrument would “not be properly determined to the determined effects.”[20]  The effect of the principle agent in creation, God the creator, is being absolutely considered.  No instrument can produce this because there is absolutely nothing which is prior to or independent of the creation of being aside from God the principle agent himself.  Thus, to hold that God used instruments in creating ex nihilo, whether they be separated intelligences or bodily agents, contradicts the meaning of creation.

3. Instrumental Creation and the Principles of Nature

In the preface of the Summa theologica version of his hexaemeron, Thomas makes use of a rather different argument to show the impossibility of creation through instruments.  Addressing the issue of angelic creation in q. 65, Thomas begins with the claims of Avicenna and the other Islamic emanationists.[21]  He rejects their view that creatures proceed from God in a series of ontologically descending stages finally resulting in the creation of the material universe.  He then remarks that their account is impossible because the creation of the material world requires the creation of matter itself.[22]  In support of this he mentions the principle that the undeveloped state is prior to the developed state in the process of generation (imperfectum enim est prius quam perfectum in fieri).  Yet, the higher intelligences of the emanationists from which the material world is supposedly generated are more perfect than material being, not less.  For there to be any sort of generation at all, there must be a more basic and less perfect substrate with respect to which generational development proceeds.  Consequently, the existence of the material universe is not the result of a generation of the less perfect from the more perfect.  Rather, it is the result of a cause that creates being and imparts to being a potentiality for further perfection of being.  Only God can create in this way, for only God can create ex nihilo—that is, making something exist without perfecting any less perfect substrate. 

Presenting an argument in support of this, Thomas begins by reminding the reader that the higher or more fundamental the cause, the more things that are effected by its causality.  Any substrate is necessarily more universal and fundamental than what determines or specifies it.  Thus, for example, existence is broader than life and life is broader than intellect.  The more a production is a substrate, the more directly its production by a higher or more fundamental cause.  So, Thomas says, with matter and form.  Considering the creation of the material world, the most fundamental substrate is matter and, therefore, this must be produced by a cause that is more fundamental than or, in Thomas’ terms “superior to,” any developmental cause of the various specified forms found in the material universe.  Thomas then reminds the reader of two points:  first, no instrumental cause can produce anything except insofar as something produced by a higher cause is presupposed in the thing produced; second, creation is the production of anything in the totality of its substance without anything presupposed.  He then draws the conclusion that the material universe cannot have been created through angelic instruments.[23]

The principles of Aristotelian natural philosophy stand behind this argument.  The intelligibility of the material universe depends upon the possibility of explaining generation.  This, as Thomas indicates, is accomplished by demonstrating the way in which an imperfect substrate is perfected through a process of formal specification.  Explanation in the sciences of nature, therefore, always requires an underlying material substrate that is available for formal development.  This requirement belongs to the very nature of generation, the subject of scientific explanation.  Indeed, the material world is intelligible precisely insofar as it is possible to provide a formal specification of an underlying material substrate accomplished through the agency of some cause.

Were the emanationists correct that the material world came into existence through the agency of higher intelligences, then the material universe would not, in itself, be intelligible.  Explanation of the generation of material substances would be in terms of those more perfect beings responsible for material production.  Indeed, in the following article, Thomas notes that this is precisely what the emanationists maintained, for they argued that the forms of material things do not subsist separately, but only in higher immaterial intelligences.  It is these immaterial intelligences, or angels, that are the ministerial or instrumental creators used by God to create the material world.[24]  They are able to create because God has imparted to them the capacity to know the corporeal forms that they thereby generate.  Thomas clearly has in mind here thinkers such as Avicenna who held that the forms found in the material universe have their origin in the intelligible forms constituting the thoughts of angels as the forms of artificial things are produced from the forms in the mind of the artificer.[25]

It has already been noted that Thomas holds that emanationism is grounded in the error of regarding material generation as the generation of a form, rather than the generation of the hylomorphic composit of matter and form.  Thomas briefly elaborates on this Aristotelian principle noting that any generation or corruption of material things is a generation or corruption of things possessing both matter and form as causes of their being.  Like produces like and, therefore, an immaterial form is not the explanation of a bodily form, but a hylomorphic composit brings another such composit into being, as when one fire is ignited by another. Consequently, the bodily forms found in the material world are not generated by an influx from some immaterial form, but by matter being reduced from potency to act by an agent that is itself composed of matter and form.[26]  Yet, this can only happen if matter is available for formal actualization.  Ultimately, matter must be available for the formal specifications that constitute the material world.  This availability of matter, this fundamental potentiality for anything to exist, cannot be the result of a process whereby potency is reduced to act.  Rather, it must be the direct imparting of being to material things with their bodily forms specifically actualizing material potentialities.  This, Thomas insists, can only be done by God “to whose command alone matter submits.”[27]

4. Conclusion

Early in his career, when he wrote his commentary on the Lombard’s Sententiae, Thomas disagreed with the common opinion of the Parisian masters that creation through instruments is philosophically impossible.  Rather, he agreed with Peter Lombard that, while instrumental creation is doctrinally false, it is philosophically plausible.  Later Thomas came to reverse his position on the basis of a sophisticated analysis of instrumentality.  Thus, in his later treatments of the Summa contra Gentiles, the Quaestiones disputatae de potentia Dei, and Summa theologica he makes it clear that the opinion of the Baghdad emanationists as well as that of the Lombard cannot stand up to close philosophical scrutiny.

In all of these treatments, Thomas’ shares the theological and doctrinal concerns of the Parisian masters.  In the arguments against angelic creation of his second hexaemeron account, however, Thomas opposes emanationism on somewhat different grounds, referring to the principles of natural philosophy.  Here, discussing creation in the context of a cosmogony of the physical world, he shifts from a focus on the nature of instruments per se to the necessity of God’s direct creation of matter.  Thomas still makes use of his analysis of instrumentality, but he is now especially concerned to understand creation ex nihilo in the context of what is necessary for the intelligibility of material natures.  In this later treatment prefacing a hexaemeron account, Thomas is concerned to reject instrumental creation in such a way so as to preserve the knowable order of material creation.  His discussion suggests that he is aware of reductionist accounts of natural being generally given by the emanationists in terms of a reduction of the principles of nature to those of mathematics.  Material beings are intelligible in terms of their own bodily being and a proper account of God’s creation must be consistant with such intelligibility.  The same Cosmogonical Fallacy that led the philosophers into an erroneous understanding of creation ex nihilo also undermines the possibility of scientific knowledge of created material nature.  Thomas’ clear and consistent rejection of this fallacy not only provides a sound philosophical foundation for true doctrine, but for research in the natural sciences as well.

References Historically Layered

BALDNER, Steven E. and William CARROLL

1997.              “Introduction” to Aquinas on Creation (Toronto: Pontifical Institute of Mediaeval Studies).

CARROLL, William E.

1988.              Big Bang Cosmology, Quantum Tunneling from Nothing and Creation,” in Laval théologique et philosophique 44: 59-75.

2000.              “Creation, Evolution, and Thomas Aquinas,” in Revue des Questions Scientifiques 171: 319-347.


1991.              “Creation Through Instruments in Thomas’ Sentence Commentary,” in Philosophy and the God of Abraham, ed. R. James Long (Toronto:  Pontifical Institute of Mediaeval Studies, 1991): 147-160.

THOMAS AQUINAS (1225—1274).

c.1252/6.       Scriptum super libros Sententiarum (In Sent.).

1259/65.        Summa contra Gentiles (SCG).

1265-66.        Quaestiones disputatae de potentia Dei (De pot.).

1266-68.        Summa theologiae, prima pars (ST Ia).

1270/1.          Sententia super Metaphysicam (In Meta.).

TORELL, Jean-Pierre (1 August 1927—).

1993.              Initiation à saint Thomas d’Aquin : Sa personne et son œuvre (Paris: Éditions du Cerf).  Reference to the English translation by Robert Royal, Saint Thomas Aquinas:  The Person and His Work (Washington, DC:  The Catholic University of America Press, 1996), vol. I.

WEISHEIPL, James A. (3 July 1923—1984 December 3).

1974.              Friar Thomas d’Aquino:  His Life, Thought, and Works (New York:  Doubleday and Company).

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