Selected essays presented at Aquinas and the Arabs / Thomas d’Aquin et ses sources arabes research seminars in North America (Fall) and Paris, France (Spring)


“Thomas’s Debts to Avicenna and Averroes on Cognition: The Commentary on the Sentences

Richard C. Taylor, Marquette University

Although this paper is essentially a commentary on Aquinas in In 2 Sent., D. 17, Q. 2, A. 1, it is in a narrative format and not in the format we intend for the commentaries which accompany our translations of selected texts from the Commentary on the Sentences.  The planned format for those commentaries is this:

(i) the issues at stake in the text of Aquinas;

(ii) the identification of the Arabic / Islamic sources of Aquinas in Latin and Arabic;

(iii) the explication of the issues and teachings in the Arabic / Islamic sources together with remarks on the accuracy of the Latin translation to convey those issues and teachings;

(iv) an analytical study and comparison of the reasoning and conclusions found in the Arabic / Islamic sources and in the text of Aquinas employing relevant modern secondary sources; and

(v) a list of references to selected later works of Aquinas where the issues at stake are discussed.

In February 2008 distinguished Aristotelian scholar and philosopher Myles Burnyeat delivered the 72nd annual Aquinas lecture at Marquette University. In that lecture Burnyeat tackled the longstanding issue of the interpretation of Aristotle’s theory of human intellect under the title, Aristotle’s Divine Intellect.1  Following the lecture, a vigorous discussion ensued with several questioners raising the issue of Aristotle’s theory of intellectual abstraction. In response Burnyeat simply denied that there is evidence in Aristotle for a theory of abstraction in the formation of intellectual understanding in human beings, that is, in the coming into being of forms in the mind. Instead, Burnyeat’s account has it that perishable human beings construct intelligibles or intelligible forms in the mind subsequent to sense perception and discursive reasoning under the guidance of God in whom all forms are present. This takes place in the mind without any sort of abstraction or separation of intelligible content derived from human experience and without transference of experienced content to the human mind. Rather, scientific knowledge in the form of intelligibles in the mind is formed in response to human experience of the world and with the guidance of the Agent Intellect of De Anima 3.5 which, following Alexander of Aphrodisias, is understood as identical to the God of Metaphysics Lambda. There is no transmission or transfer of some logos or ratio in the things of the world to the human intellect by some sort of abstraction.2  The questions concerning abstraction left Burnyeat genuinely puzzled and he later asked why so many in the audience repeatedly raised these questions, when there is no explicit discussion of intellectual abstraction by Aristotle in the epistemological contexts of the De Anima.3

In the present article my goal is not to grapple with the question of whether Aristotle taught a doctrine of intelligibles abstracted or separated from the content of perception by some process but rather to show that it was from translated works of Avicenna and Averroes that Aquinas and other Christian theologians and philosophical thinkers received the doctrine of abstraction that played an important role in European thinkers of the High Middle Ages subsequent to those translations. The reaction to the presentation by Burnyeat described above and Burnyeat’s own interpretation of Aristotle are valuable reminders of the underdetermined character of the texts of Aristotle and also of the importance of reading philosophical and theological texts with a sound understanding of the history of the development of philosophical doctrines. My focus is on the teachings of Thomas Aquinas in his Commentary on the Sentences of Peter Lombard regarding the formation of intelligible species and abstraction. Neither of these teachings of Aquinas is to be found explicitly in the De Anima of Aristotle. Further, neither teaching ͞͞— in the complexity and coherence with which Aquinas sets it forth — is found in the Latin, Greek or Arabic tradition before Aquinas. However, as will be seen, the proximate and foundational source for the development of Aquinas’s teaching on intelligible species can be found in Avicenna’s Metaphysics which is also a source for an account of abstraction, although the precise understanding of abstraction as the garnering of content of intelligibles in act from sensible experience through a process of abstraction taught by Aquinas is not found in Avicenna but can be found in the Long Commentary on the De Anima by Averroes.  In the course of establishing this it will become quite clear how insightful  and astute a reader of the translated works of Avicenna and Averroes Aquinas was at the time of writing the Commentary on the Sentences and also how very well developed were his skills of critical reading and argumentative analysis.

1. Aquinas in In 2 Sent, D. 17, Q. 2, A. 1,4

“Whether there is one soul or intellect for all human beings”

In In 2 Sent, D. 17, Q. 2, A. 1 the question driving the analysis of Aquinas bears on the teachings of Theophrastus,  Alexander of Aphrodisias, Themistius, Avicenna, and Ibn Bâjjah (Avempace), as well as Averroes,5 since, as Aquinas writes,

nearly all the philosophers after Aristotle are in agreement that the agent intellect and the possible [intellect] differ in substance and that the agent intellect is a certain separate substance both last among the separate intelligences and related to the possible intellect as that by which we understand, as higher intelligences [are related] to the souls of the spheres.6

In forming this view of post-Aristotelian philosophy Aquinas drew primarily upon two philosophical sources,  first, the Long Commentary on the De Anima of Aristotle7 by Averroes for all the teachings of the other philosophers mentioned above except Avicenna and for the doctrine and arguments of Averroes himself and, second, the Latin translation of Avicenna’s De Anima and Metaphysics for the Persian philosopher’s own teachings on the soul.8

Aquinas proceeds to his critical analysis of the views of the philosophers on the unity of intellect by dividing them into three groupings.  The first group is that of Alexander and Ibn Bâjjah / Avempace who regard the possible intellect as corruptible with the body. The second grouping consists just of Avicenna who holds the possible intellect to be multiplied and distinct in individual human beings, with its subject not the body or a bodily power but the essence of the rational soul itself. Avicenna also holds the soul to come into being with the human body but to persist in existence after the death of the body.9 The third view is that “the possible intellect is one for all [human beings],” which Aquinas subdivides into two: the view of Themistius and Theophrastus with a refutation by Averroes and the view of Averroes with a refutation by Aquinas.  Aquinas concludes the Response with his own views which involve accepting principles from Avicenna and Averroes and incorporating them into his own understanding of agent intellect and possible intellect as powers belonging individually to particular  human souls.  It should be noted, however, that with the exception of two sentences on the teaching of Avicenna, the sole source for Aquinas on these thinkers is the Long Commentary on the De Anima by Averroes.10 But here Avicenna is the focus of attention.

2. Avicenna’s Epistemology According to Aquinas in In 2 Sent, D. 17, Q. 2, A. 1,

In the Response Aquinas finds much to his liking the view of Avicenna that the possible or material intellect belongs to each human being as an individual and immaterial power of the rational soul.  The rational soul comes into existence with the body but does not perish with the death of the body. To this extent, Avicenna’s view is in accord with the Catholic faith, although his view that there is one Agent Intellect for all human beings is something that Aquinas rejected as erroneous.11  From the two mentions of this in the Response of the article, the extent of the importance of Avicenna to the thought of Aquinas appears more modest that it is in fact.

His appreciation of Avicenna is more clear in the response to the third objection.12 That objection reflects the view of Averroes and claims that, if there were a plurality of individual human intellects in accord with the number of human bodies, then the understood forms would also be individuated in each human possible intellect. That individuation would make the received form no longer an intelligible in act as an understood universal essence required for knowledge.  Rather, it would be a particular form individuated by the particular human intellect receiving it.  And in that case knowledge of intelligibles would then require that there be another intelligible over that one, and so forth to infinity.13 The individuation occurring in each particular human intellect would be the same sort as that occurring in the reception of a form by prime matter, with the result that the possible intellect will be no more of a knowing power than is prime matter.  As the objector puts it, “in the case of both they are received insofar as they are those [determinate particulars] and not as are forms taken absolutely. Hence, just as prime matter does not know forms which it receives, so too neither [does] the possible intellect [understand forms which it receives], as it seems.”14  That is, insofar as form is particularized and consequently not intelligible when received into matter, so too form received into a particular human possible or material intellect would also be particularized and not intelligible.15

In responding to the third objection, Aquinas refuses to accept this analysis set forth by Averroes and instead follows Avicenna.  In his De Anima Avicenna says that the formation of universal intelligible intentions altogether separate from matter is the most proper characteristic of human beings.16 He later argues that the receptive subject of intelligible forms must be an immaterial substance.  In regard to the ultimate sort of abstraction,17 Avicenna then explains that the human rational power considers individuals in the imagination and next the light of the Agent Intellect strips materiality from these intelligibles in potency and emanates the immaterial intelligible in act upon the rational soul.  According to Avicenna, “What are in the imagination are intelligibles in potency and they become intelligibles in act, [though] not the very same things but what are taken from them.”18 For him, then, the being that an intelligible in act has in the human intellect of an individual is distinct from the being of the intelligible in potency in the imagination since the latter is the being of a particular or singular because of its relation to the particular or singular in the world which is the cause of the image in the imagination.19  Note, however, that there is more to what Avicenna says here than may be immediately apparent, for he goes on to show that he rejects the Aristotelian notion that the knower becomes what it knows. Avicenna continues the passage quoted just above, as follows.

Instead, the affect coming about by way of the light from sensible forms is not those very forms but rather another thing similar to them that the light generates in the receiving subject opposite. Likewise, when the rational soul views these imagined forms and the light of the Agent Intellect conjoins with it by a kind of conjunction, [the rational soul] is made prepared for the light of the Agent Intellect to bring about in it the abstractions of those forms from the mixtures.20

That is, just as, for example, reflected light on a wall is not precisely the light of the sun but something similar to it brought about on something opposite to the wall, so too when the light of the Agent Intellect shines on imagined forms and conjoins with the soul it generates a likeness which enables the soul to apprehend separate forms and have knowledge by emanation from or conjunction with the Agent Intellect. In this sort of representationalism Aquinas does not follow Avicenna.21

Aquinas follows Avicenna in holding the species or form as understood can be considered either with regard to the being it has of its own nature in a human intellect whereby it has “singular being,” or insofar as it is a likeness of the thing understood whereby it “leads to knowledge of [the thing understood], and on the basis of this consideration it has universality.” That is, the understood form or intelligible species is a likeness not insofar as it is of a particular thing but “according to the nature in which it agrees with others of its species.” As a representation of the nature or kind of the thing experienced, the intelligible species is the foundation for the formation of the universal in the intellect for Aquinas.  Contrary to the view of Averroes for whom particularity of subject necessarily involves the particularization of what is received into a particular subject and, consequently, the loss of intelligible being,22 Aquinas holds that the reception of the intelligible species as a likeness of the nature does not involve the contraction of the received intelligible species into particularity or singularity.  This is simply because matter is the cause of this particularization in concrete things of the world, while in the case of human intellectual understanding the receiving subject is immaterial.  The received intelligible form or species in a singular human intellect is indeed in a singular receptive subject for Aquinas. But insofar as the subject is immaterial, the received intelligible form or species — as a content bearing likeness representing the nature of the thing, the nature which comes to be in the soul in intellectual understanding — is not contracted to particularity or transformed into an intelligible in potency, contrary to what Averroes holds.  As is evident in the case of separate substances as immaterial intelligences, reasons Aquinas, an intelligible form or species may be individuated insofar as it belongs to its immaterial subject, an understanding mind, “But that species is individuated through the individuation of the intellect and, consequently, it does not lose intelligible being in act.” That is, the concern with particularization is a false one for Aquinas, “because the mode of individuation through intellect is other than [the mode of individuation] through prime matter.”23  The presence of intelligible species belonging individually to a plurality of human intellects does not multiply the nature of the thing understood, the nature which is the object of knowledge. This is perhaps the earliest account in Aquinas of his epistemological teaching on intelligible species and on the location of the object of knowledge as the natures in things.

For his argument against Averroes here Aquinas is drawing on Avicenna’s Metaphysics, book 5, chapters 1 and 2.  There Avicenna argues for this plurality of individual human intellects.  In the Latin version of the text at the end of chapter 1, we find Avicenna writing,

This form . . . , although it is universal with respect to individuals, nevertheless, with respect to the singular soul in which it is impressed, it is individual, for it is one of the forms which are in the intellect.  And because singular souls are many in number, then in the way in which they are particulars they themselves will have a different universal notion. . . .24

That is, the intelligible notion must exist in the intellects of a plurality of individual human beings without losing its intelligibility.  For Avicenna the intelligible comes to be in the soul’s apprehension of something universal in its relation to a plurality of individuals. As Avicenna puts it, “Universality accrues to some nature only when [the nature] comes to be in mental conception.”25  The understood intelligible or species, then, has according to Avicenna precisely the two modes of consideration of which Aquinas speaks in the response to the third objection, consideration insofar as it is an understood intelligible possessed by an individual human intellect and consideration insofar as it is a universal intelligible in relation to the many particulars of the world.26 

What is more, we can see in book 5, chapter 2, of Avicenna’s Metaphysics the foundations for the teaching of Aquinas that intelligible species are representative of and derived from the natures of particular things so that the form may come into the soul and the nature be understood.  At In 2 Sent., d. 3, q. 3, a.1, resp., Aquinas writes,

[I]n the human intellect the likeness of the thing understood is different from the substance of the intellect and is as its form.  Hence, from the intellect and the likeness of the thing there is made one complete thing which is the intellect understanding in act, and the likeness has been taken from the thing.27 

The Latin version of Avicenna has the following:

Therefore, when we say that the universal nature has being in these sensibles, we do not understand that from the fact that it is universal, namely, according to this mode of universality, but rather we understand that the nature to which universality accrues has being in these determinate particulars. Therefore, from the fact that it is a nature, it is one thing; and from the fact that it is able to be understood as a universal form, it is something else.28

Note, however, that while Aquinas founds his understanding on the Aristotelian notion that the thing comes to be or exist in the soul,29 Avicenna himself rejects that notion and embraces a form of representationalism.30

Aquinas could not accept the notion of one separate Agent Intellect shared by all human beings common to Avicenna and the Arabic tradition.  As seen above, Avicenna held that what is most characteristic of human beings is to form universal intelligible intentions altogether separate from matter.31  But Avicenna was acutely aware of the problem of a suitable subject for intelligibles in act and, following Aristotle, asserted that it is inappropriate for the subject to be a body or something dependent upon a body.  Properly speaking, intelligibles in act themselves should not be thought to have place, according to Avicenna and al-Fârâbî before him; rather, they have place only insofar as they are in some way conjoined with a body.32  For, were intelligibles literally to exist in a body having place, they could not then be intelligibles.33  While human formation of images in the imagination subsequent to sense perception is necessary, the formation of immaterial intelligibles in the soul can come about only thanks to a conjoining with the Agent Intellect.34  The Agent Intellect in a way gives intelligibles to the soul, not by a changing, transforming or transferring of imagined forms in the imagination into intelligible forms in the human intellect after the manner of abstraction, but rather by emanating (يفيض, emanet) the immaterial intelligible forms to the soul when the soul  has been suitably prepared for reception through sense perception and the workings of the internal sense powers.35  Human learning of intelligibles, then, involves seeking after complete conjoining (اتصال) with the Agent Intellect to obtain this emanation of forms to the soul. These emanated intelligibles are not the unique intelligibles in act in the Agent Intellect but likenesses of those transcendent intelligibles in act.  In the human soul they do not persist or remain in an individual intellectual memory but rather the soul comes to possess the acquired intellect whereby it can at will conjoin once more with the Agent Intellect and again receive the emanation of the intelligibles for each instance of intellectual understanding.36  For Avicenna, then, the intelligibles in act as such are present to individual human intellects only when human rational souls are conjoined with the Agent Intellect. These intelligibles in individual human rational souls may be called intelligible species or forms, though their source is the Agent Intellect and not the abstracted natures of things as Averroes and Aquinas hold.

In sum, although their teachings differ in important ways, Aquinas finds in Avicenna (i) reasoning on the nature of the immaterial rational soul that permits the presence of intelligible species multiplied in a plurality of individual souls and (ii) reasoning in support of the view that the objects of intellectual understanding are the natures of things of the world in the words of Avicenna asserting that “the nature to which universality accrues has being in these determinate particulars.” However, Aquinas disagrees on the existence of a single Agent Intellect, instead holding that each human being has his or her own individual power of soul called agent intellect. He also disagrees on the locus of intelligibles insofar as the intelligibles known in or by the separate Agent Intellect but instead the intelligibles are known in act are the intellectual apprehension of the natures of things of the world.

3. Averroes’s Long Commentary on the De Anima

as the Source for the Abstraction of Intelligibles in Aquinas

Avicenna holds that sensory experience of the world prepares the rational soul for an emanation or conjoining with the Agent Intellect for the apprehension of intelligibles in act, the ultimate result of several sorts of human processes of abstraction.37 In contrast, Averroes set out a very different doctrine of abstraction founded on the thought of al-Fârâbî.38  While Aquinas was not aware of the close connection to the reasoning of al-Fârâbî, he read Averroes’s critique of Avicenna in the Long Commentary on the De Anima that intelligibles must come through abstraction from sensibles and not directly from the Agent Intellect simply because the latter would leave no teleological value to the senses and internal sense powers. Rather, the function of sense and of the subsequent processes of imagination and cogitation is to provide the content on which the separate Agent Intellect will act. He writes,

Now [Aristotle] gives the way on the basis of which it was necessary to assert the agent intelligence to be in the soul. For we cannot say that the relation of the agent intellect in the soul to the generated intelligible is just as the relation of the artistry to the art’s product in every way. For art imposes the form on the whole matter without it being the case that there was something of the intention of the form existing in the matter before the artistry has made it. It is not so in the case of the intellect, for if it were so in the case of the intellect, then a human being would not need sense or imagination for apprehending intelligibles. Rather, the intelligibles would enter into the material intellect from the agent intellect, without the material intellect needing to behold sensible forms. And neither can we even say that the imagined intentions are solely what move the material intellect and draw it out from potency into act. For if it were so, then there would be no difference between the universal and the individual, and then the intellect would be of the genus of the imaginative power. Hence, in view of our having asserted that the relation of the imagined intentions {439} to the material intellect is just as the relation of the sensibles to the senses (as Aristotle will say later), it is necessary to suppose that there is another mover which makes [the intentions] move the material intellect in act, and this is nothing but to make [the intentions] intelligible in act by separating them from matter.39

Since the existence of knowledge in individual human beings is obvious in experience, Averroes, like Aquinas later, conceived the agent intellect and the material or receptive intellect to be “in the soul” of individual human knowers. In this they were both following Aristotle himself who explicitly stated just that.40 However, while they agreed on that wording for their doctrines, the meanings of the words were quite different for each of them.  For Aquinas this meant that the powers called the active intellect and the receptive, possible or material intellect belonged as intrinsic powers of each human soul following upon the essential definition of human beings as rational animals with intellectual powers.  For Averroes, however, the words meant that two transcendent entities, the Agent Intellect and the Material Intellect, come to be present in and shared by the individual knower who has agency insofar as knowledge is sought out by will.  He writes,

It was necessary to ascribe these two activities to the soul in us, namely, to receive the intelligible and to make it, although the agent and the recipient are eternal substances, on account of the fact that these two activities are reduced to our will, namely, to abstract intelligibles and to understand them. For to abstract is nothing other than to make imagined intentions intelligible in act after they were [intelligible] in potency. But to understand is nothing other than to receive these intentions. For when we found the same thing, namely, the imagined intentions, is transferred in its being from one order into another, we said that this must be from an agent cause and a recipient cause. The recipient, however, is the material [intellect] and the agent is [the intellect] which brings [this] about.41

Averroes also accepted from Themistius the notion that there has to be a single set of intelligibles for intersubjective discourse and the shared understanding of the truths of science or theoretical knowledge and, in a way very different from the thought of Themistius, also conceived the Material Intellect as a necessarily immaterial subject for receiving these shared truths as immaterial intelligibles.42  Themistius grounded abstraction on the part of individuals in the guidance provided by the Agent (or Productive) Intellect which contains in it the intelligibles and also supervenes upon the individual to guide the abstractive process by which intelligibles are abstracted from experience and come into the individual human receptive or material intellect. Averroes, however, held for a realism of a single set of intellectually understood forms because individuals could not come to be informed with their own sets of the intelligibles in act without multiplying the intelligible referents of knowledge and thereby losing the unity of science and falling into particularity, as we saw earlier in the discussion of the third objection.  Rather, for Averroes there is a genuine abstraction of intelligible content from sensory experience since the Agent Intellect does not provide intelligible content but only an abstractive power which transfers intelligibles in potency to a new level of being as intelligibles in act.

While Aquinas did not fully appreciate the context and argumentative foundations of Averroes’s reasoning on how the separate Agent Intellect and separate Material Intellect were conceived as intrinsically present in the soul,43 he still had a strong understanding of what Averroes taught. This is clear in In 2 Sent, D. 17, Q. 2, A. 1, resp. when he describes Averroes as holding that “the understood species abstracted from phantasms are as form of the possible intellect [and that] from the two of these there comes to be the intellect in a positive disposition (intellectus in habitu).”44 That is, the content of the possible (material) intellect comes from forms (phantasms) intelligible in potency in the imagination subsequent to sensory experience.

Of course, Aquinas goes on to criticize the view of Averroes that the active and receptive powers in the soul are to be identified as separately existing eternal intellects, the Material Intellect and the Agent Intellect, shared by all human beings. I have shown elsewhere that this critique does not constitute a refutation since Averroes is reasoning in a very different philosophical framework than the one which Aquinas attributes to him, in particular with reference to the way in which Material Intellect and Agent Intellect are “in the soul.”45  Regardless of that, it is noteworthy that Aquinas accepted the necessity of the presence of these “in the soul” from Averroes, made the phrase his own, located these as powers in the soul, and continued to repeat the same line of critical reasoning against Averroes which is found here throughout his career.46 Still, it is evident that it is Averroes, not Aristotle and not Avicenna, who unequivocally taught Aquinas and others of the Latin tradition the doctrine of abstraction even now erroneously often thought easily to be evident in Aristotle by some.

With the sort of teaching on abstraction in Averroes, Aquinas found what he deemed a more correct way in which experience of the world is a source for intellectual understanding. While in Avicenna the natures in things of the world were a starting point for intellectual understanding, it is the intelligibles in act in the Agent Intellect that are the ultimate objects of understanding. But Averroes more firmly made the very natures of things of the world as starting points or principles, although under the sway of arguments from Themistius he chose to resolve longstanding problems in his thought concerning just how to consider intelligibles in act by asserting the existence of a single shared Material Intellect as the required immaterial subject for intelligibles in act.47 To that extent, what is understood in human intellectual understanding for Averroes is what comes to be in the Material Intellect, the intelligibles in act, albeit derived from experience of the world. Rather than follow Avicenna in his Alexandrian conception of the soul as an immaterial rational entity,48 Averroes in his commentaries on the De Anima consistently thought of the human soul as perishable and as unable to be the subject of intelligibles. Instead of raising the soul to immateriality, he conceived of the Material Intellect and Agent Intellect as coming down into the transitory human soul as powers to be used and shared in intellectual understanding.

4. Conclusion

In the Long Commentary on the De Anima by Averroes Aquinas found spelled out a detailed account reasoning that the content of natural human intellectual understanding must come from sensory apprehension of the world through a process of abstraction whereby images or phantasms derived from sense are raised beyond their natures as sensible species or forms. In this there takes place a transference of the intelligible content of that sensible form from being intelligible in potency to being intelligible in act by an active power of intellect and this is received by a receptive power of intellect.49 In Avicenna’s Metaphysics 5.1-2 Aquinas found passages supporting the view that the natures of things are found existing as determinate particulars in natural things and that it is these natures to which universality accrues only when they are in the human intellect and only while a human is receiving an emanation from or experiencing a conjoining with the separate and unique Agent Intellect. This supported discussions of Avicenna’s own understanding of the process of abstraction discussed in Book 5 of his De Anima. Moreover, it is in Book 5 of the De Anima of Avicenna that Aquinas found reasoning for the plurality of individual human intellects as receptive of intellectual forms multiplied in those intellects, reasoning which Aquinas turned against Averroes to establish his own view.

It is better known, of course, that Aquinas differed deeply and at times fiercely with the views of these two philosophers of the Arabic tradition. But, without the reasoned accounts of these philosophers as guides in philosophy, the comprehensive synthetic account of natural epistemology set forth by Aquinas would not have been possible.  And it is that much read account of Aquinas and its influence which is one of the roots, perhaps even the most influential root, of abstractionist interpretations of Aristotle’s De Anima today. Aquinas’s main source for the doctrine of abstraction, however, was Averroes most clearly, together with some suggestive guidance from Avicenna.

1 M. F. Burnyeat, Aristotle’s Divine Intellect [The Aquinas Lecture, 2008] (Milwaukee: Marquette University Press, 2008).

2 See Burnyeat 2008, pp. 37-43. I am inclined to think that, rather than the texts of Aristotle himself, it is the prominence of the later Greek and Medieval Latin abstractionist accounts of Aristotle by Aquinas and others that was responsible for the audience’s questions and challenges which presumed the presence of that teaching to be explicit in Aristotle when in fact it is far from being so.

3 There are some very suggestive and perhaps challenging passages. Most noteworthy is De Anima 3.8, 432a5: ἐν τοῖς εἰδεσι τοῖς αἰσθητοῖς τὰ νοητά ἐστι: “the intelligibles are in the sensible forms.” This passage might lend support to the idea that not just the forms of things but also the forms of things as objects of knowledge (νοητά) are there in potency in the things and so able to be abstracted. Of course, such an interpretation is not necessary on Burnyeat’s account since God is the cause of the forms of the world and the guiding cause of the forms constructed in the human mind.   As will become clear, the language of abstraction in the apprehension of knowledge is by no means prominent in Aristotle. However, it does appear in Alexander and through him and perhaps others of the later Greek tradition it was passed on to the Arabic tradition. See Alexander of Aphrodisias, De Anima Liber Cum Mantissa, Ivo Bruns (ed.). Berlin: Typis et Impensis Georgii Reimer, 1887. [Commentaria in Aristotelem Graeca, Suppl. II, pt. 1], 111.15-18; “Moreover, its producing is prior and [part of] its substance. First it produces by abstraction [something] intelligible, and then in this way it apprehends some one of these things which it thinks and defines as a this-something. Even if it separates and apprehends at the same time, nevertheless the separating is conceptually prior for this is what it is for it to be able to apprehend the form.” Alexander of Aphrodisias. Supplement to One the Soul, tr. R. W. Sharples (London: Duckworth, 2004) p. 36.  Also see 29.16-20 and especially 84.14-85.10 available in French translation in Alexandre d’Aphrodise, De l’Âme. Texte grec, traduit et annoté, Martin Bergeron and Richard Dufour (Paris: Vrin, 2008), pp. 74-74 and 202-203, respectively.

4 For an analysis of this article with an English translation based on a revised text provided by Dr. Adriano Oliva,O.P., of the Commissio Leonina, see Richard C. Taylor, “Aquinas and the Arabs: Aquinas’s First Critical Encounter with the Doctrine of Averroes on the Intellect, In 2 Sent. d. 17, q. 2, a. 1,”  in Philosophical Psychology in Medieval Aristotelianism, Luis Xavier López-Farjeat and Jörg Tellkamp, eds. (forthcoming).

5 It is curious that Aquinas neglects to mention al-Fârâbî in this context since the latter’s Letter on the Intellect or De intellectu was available in Latin translation. Perhaps the reason for this was that this work was not easily at hand for Aquinas. Another reason may be that, while he made extensive use of the Long Commentary on the De Anima of Aristotle by Averroes as will be shown below, he did not fully understand the critical accounts of the teachings of al-Fârâbî as set forth by Averroes. The Latin text of al-Fârâbî’s De Intellectu was edited and discussed by Etienne Gilson in “Les sources greco-arabes de l'augustinisme avicennisant,” Archive d'histoire doctrinale et litteraire du moyen age 4 (1929),  4-149; see 115-126.  For a discussion of the importance of the teachings of al-Fârâbî to the development of the thought of Aquinas, see Richard C. Taylor, “Abstraction in al-Fârâbî,” Proceedings of the American Catholic Philosophical Association 80 (2006) 151-168. For a general account of the thought of al-Fârâbî, see Herbert A. Davidson, Alfarabi, Avicenna, and Averroes, on Intellect. Their Cosmologies, Theories of the Active Intellect, and Theories of Human Intellect (Oxford: Oxford University Press, 1992), 44-73. Also see Philippe Vallat, Farabi et l’École d’Alexandrie (Paris: Libairie philosophique J. Vrin, 2004). For a brief account of al-Fârâbî, see David C. Reisman, “Al-Fârâbî and the philosophical curriculum,” in The Cambridge Companion to Arabic Philosophy, Peter Adamson and Richard C. Taylor, eds. (Cambridge: Cambridge University Press, 2005), 52-71.

6 . . . in hoc fere omnes philosophi | concordant post Aristotilem, quod intellectus | agens et possibilis differant secundum substantiam, et quod | intellectus agens sit substantia quedam separata, et est 110 postrema in intelligentiis separatis et habet se ita ad | intellectum possibilem quo intelligimus sicut intelligentie | superiores ad animas orbium. In 2 Sent., d. 17, q. 2, a. 1, resp. Re. this text, see note 4 above.

7 De Anima: Averrois Cordubensis Commentarium Magnum in Aristotelis De Anima Libros,  Crawford, F. S., ed. Cambridge, MA, 1953. This work will be cited as LCDA with page numbers in brackets { }. An English translation of this is now available. See Averroes of Cordoba’s Long Commentary on the De anima of Aristotle, Richard C. Taylor, tr. and intro., Therese-Anne Druart, subeditor.  (New Haven: Yale University Press, 2009). This translation will be cited in what follows as LCDA, Taylor, tr. Among the key texts in Averroes are LCDA Book 3, Texts and Comments 5, 18-20, and 36.

8 For Avicenna, the key texts are Kitâb al-Shifâ’, al-Nafs in Avicenna’s De Anima (Arabic Text) Being the Psychological Part of the Kitâb al-Shifâ’, F. Rahman, ed. (London: Oxford University Press, 1959), in particular Book 5, chapters 1-2, 5-6; and Ibn Sînâ, al-Shifâ’. Al-Ilâhiyyât, G. C. Anawati and Sa’id Zayed, ed. (Cairo: Organisation Générale des Imprimeries Gouvernementales, 1960), v. 2, 5.1, 205-6. The corresponding Latin texts are found in Avicenna Latinus. Liber De Anima seu Sextus de Naturalibus IV-V, S. Van Riet, ed. (Louvain: Editions Orientalistes, and Leiden: E. J. Brill, 1968); and  Avicenna Latinus. Liber de Philosophia Prima sive Scientia Divine, V-X (Leuven: E. Peeters, & Leiden: E. J. Brill, 1980).

9 The Latin here conveys an accurate account of the view of Avicenna. For a detailed account of the reasoning involved, see Robert Wisnovsky, Avicenna’s Metaphysics in Context (Ithaca, NY: Cornell University Press, 2003), Ch. 6 “Avicenna on Perfection and Soul. The Issue of Separability,” 113-141.  For a brief account of Avicenna’s view by Wisnovsky in “Avicenna and the Avicennian Tradition,” The Cambridge Companion to Arabic Philosophy, eds. Peter Adamson and Richard C. Taylor (Cambridge: Cambridge University Press, 2005) 92-136, specifically 96-105.  Also see Davidson, Alfarabi, Avicenna, and Averroes on Intellect, 1992.

10 See LCDA 3.5, {387-413}; Taylor tr., 303-29.

11 In 2 Sent. d. 17, q. 2, a. 1, lines 175-181: Et ideo tertia opinio est Auicenne, que ponit intellectum | possibilem in diuersis diuersum, fundatum in essentia | anime rationalis, et non esse uirtutem corporalem, cum corpore | incipere set non cum corpore finiri. Vnde quantum ad | intellectum possibilem eius opinio est quam tenemus secundum 180 fidem catholicam, quamuis erret cum aliis de intellectu | agente, ut dictum est. “For this reason there is the third opinion  belonging to Avicenna, who holds the possible intellect to be diverse in diverse individuals, to be founded upon the essence of the rational soul and not to be a bodily power, to begin to exist with the body but not to come to an end with the body. Hence, with respect to the possible intellect, his opinion is what we hold according to the Catholic faith, although he errs with others concerning the agent intellect, as was said.” Lines 310-14: . . .  remotis omnibus predictis erroribus, dico | cum Auicenna, intellectum possibilem incipere quidem | esse set cum corpore non deficere, et in diuersis diuersum | esse, et multiplicari secundum diuisionem materie in | diuersis indiuiduis sicut alias formas substantiales. “. . . when all the errors mentioned have been set aside, I say with Avicenna that the possible intellect begins to exist in the body, but does not go out of existence with the body, that it is diverse in diverse [human beings], and that it is multiplied according to the division of matter in diverse individuals, just as other substantial forms.”

12 In 2 Sent. d. 17, q. 2, a. 1, lines 395-411: Ad tertium dicendum, quod secundum Auicennam species | intellecta potest dupliciter considerari: aut secundum | esse quod habet in intellectu, et sic habet esse singulare, | aut secundum quod est similitudo talis rei intellecte, prout | ducit in cognitionem eius, et ex hac parte habet uniuersalitatem: 400 quia non est similitudo huius rei secundum | quod est hec res set secundum naturam in qua cum aliis | sue speciei conuenit. Nec oportet omne singulare esse intelligibile | tantum in potentia, sicut patet de substantiis | separatis, set in illis que indiuiduantur per materiam, 405 sicut sunt corporalia. Set species illa indiuiduatur | per indiuiduationem intellectus, unde non perdit esse | intelligibile in actu; sicut intelligo me intelligere, | quamuis ipsum meum intelligere sit quedam operatio | singularis. Patet etiam per se quod secundum inconueniens 410 non sequitur: quia alius modus est indiuiduationis per | intellectum et per materiam primam. “To the third it should be said that, according to Avicenna, the understood species can be considered in two ways, either with respect to the being that it has in the intellect, and in this way it has singular being, or with respect to the fact that it is a likeness of such an understood thing, to the extent that it leads to the knowledge of it, and on the basis of this part it has universality. [This is] because it is not a likeness of this thing insofar as it is this thing but rather according to the nature in which it agrees with others of its species.  Nor is it necessary that every singular being be intelligible in potency alone, as is clear concerning separate substances. But [it is necessary] in regard to those which are individuated by matter, as are bodies. But that species is individuated through the individuation of the intellect and, consequently, it does not lose intelligible being in act. [This is] just as I understand that I understand, although my understanding is a certain singular operation. It is also evident in itself that the second unacceptable consequence does not follow, because the mode of individuation through intellect is other than [the mode of individuation] through prime matter.”

13 Et si posuerimus eum esse multa, continget ut res intellecta apud me et apud te sit una in specie et due in individuo; et sic res intellecta habebit rem intellectam, et sic procedit in infinitum. “If we assert it [scil., the intelligible] to be many, then it would happen that the thing understood in me and in you would be one in species and two in individual [number]. In this way the thing understood will have a thing understood and so it proceeds into infinity.” Averroes, LCDA {411}, Taylor tr. 328. . . . prima materia recipit formas diversas, scilicet individuales et istas, ista autem recipit formas universales  “. . . prime matter receives diverse forms, namely, individual and particular forms, while this [nature] receives universal forms.” Averroes, LCDA {388}, Taylor tr. 304.  See the continuation of Averroes’s account at LDCA {388}, Taylor tr. 304-5.

14 In 2 Sent. d. 17, q. 2, a. 1, lines 40-43: . . . quia utrobique | recipiuntur ut sunt iste, et non ut sunt forme simpliciter; | et ita, sicut materia prima non cognoscit formas | quas recipit, ita nec intellectus possibilis, ut uidetur.

15 The chief source of these issues raised in this objection are the texts of Averroes who argues that the Material Intellect (which Aquinas calls possible intellect) must be one immaterially separate and shared power since it receives universal forms into itself as subject of intelligibles.  Were it to be a particular power, it would receive forms in accord with its particular nature as diverse particulars. Hence, in order to be receptive of intelligible forms without contracting them to the particularity which would take place were there many individual material intellects, Averroes holds for a single, shared incorporeal Material Intellect as satisfying his concern about particularization.  Averroes writes regarding the reception of universals forms in the Material Intellect,

Et causa propter quam ista natura est distinguens et cognoscens, prima autem materia neque cognoscens neque distinguens, est quia prima materia recipit formas diversas, scilicet individuales et istas, ista autem recipit formas universales. Et ex hoc apparet quod ista natura non est aliquid hoc, neque corpus neque virtus in corpore; quoniam, si ita esset, tunc reciperet formas secundum quod sunt diversa et ista, et si ita esset, tunc forme existentes in ipsa essent intellecte in potentia, et sic non distingueret naturam formarum secundum quod sunt forme, sicut est dispositio in formis individualibus, sive spiritualibus sive corporalibus. Et ideo necesse est, si ista natura que dicitur intellectus recipit formas, ut recipiat formas modo alio receptionis ab eo secundum quem iste materie recipiunt formas quarum conclusio materia est terminatio prime materie in eis. LCDA, 388.

The reason why that nature is something which discerns and knows while prime matter neither knows nor discerns, is because prime matter receives diverse forms, namely, individual and particular forms, while this [nature] receives universal forms. From this it is apparent that this nature is not a determinate particular nor a body nor a power in a body. For if it were so, then it would receive forms inasmuch as they are diverse and particular; and if it were so, then the forms existing in it would be intelligibles in potency; and thus it would not discern the nature of the forms inasmuch as they are forms, as is the disposition in the case of individual forms, be they spiritual or corporeal. For this reason, if that nature which is called intellect receives forms, it must receive forms by a mode of reception other than that by which those matters receive the forms whose contraction by matter is the determination of prime matter in them. Taylor tr., 304-5.

In this Averroes was also motivated by his reflections on the Paraphrase of the De Anima by Themistius to posit a single shared Material Intellect out of concern for the unity of scientific or intelligible discourse that makes intersubjective discourse and understanding possible. The key role of Themistius in the development of Averroes’ thought in the Long Commentary on the De Anima is discussed in LCDA, Taylor, tr., introduction, lxii ff.; and in my “Themistius and the Development of Averroes’ Noetics,” in Soul and Mind. Medieval Perspectives on Aristotle's De Anima (Philosophes Médiévaux LII),  J.-M. Counet and R. Friedman, ed. (Peeters, Leuven, forthcoming). Averroes writes,

Et iste modus secundum quem posuimus essentiam intellectus materialis dissolvit omnes questiones contingentes huic quod ponimus quod intellectus est unus et multa. Quoniam, si res intellecta apud me et apud te fuerit una omnibus modis, continget quod, cum ego scirem aliquod intellectum, ut tu scires etiam ipsum, et alia multa impossibilia. Et si posuerimus eum esse multa, continget ut res intellecta apud me et apud te sit una in specie et due in individuo; et sic res intellecta habebit rem intellectam, et sic procedit in infinitum. Et sic erit impossibile ut discipulus addiscat a magistro, nisi scientia que est in magistro sit virtus generans et creans scientiam que est in discipulo, ad modum secundum quem iste ignis generat alium / ignem sibi similem in specie; quod est impossibile. Et hoc quod scitum est idem in magistro et discipulo ex hoc modo fecit Platonem credere quod disciplina esset rememoratio. Cum igitur posuerimus rem intelligibilem que est apud me et apud te multam in subiecto secundum quod est vera, scilicet formas ymaginationis, et unam in subiecto per quod est intellectus ens (et est materialis), dissolvuntur iste questiones perfecte. LCDA, 411-12. That way in which we posited the being of the material intellect solves all the questions resulting from our holding that the intellect is one and many. For if the thing understood in me and in you were one in every way, it would happen that when I would know some intelligible, you would also know it, and many other impossible things [would also follow]. If we assert it to be many, then it would happen that the thing understood in me and in you would be one in species and two in individual [number]. In this way the thing understood will have a thing understood and so it proceeds into infinity. Thus, it / will be impossible for a student to learn from a teacher unless the knowledge which is in the teacher is a power generating and creating the knowledge which is in the student, in the way in which one fire generates another {412} fire similar to it in species, which is impossible. That what is known is the same in the teacher and the student in this way caused Plato to believe that learning is recollection. Since, then, we asserted that the intelligible thing which is in me and in you is many in subject insofar as it is true, namely, the forms of the imagination, and one in the subject in virtue of which it is an existing intellect (namely, the material [intellect]), those questions are completely resolved. Taylor tr., 328-29.

16 See note 19 for the text.

17 On the multiple sorts of abstractions or separations in Avicenna, see Cristina D’ Ancona, “Degrees of Abstraction in Avicenna,” in Theories of Perception in Medieval and Early Modern Philosophy, edited by Simo Knuuttila and Pekka Karkkainen (Dordrecht: Springer, 2008), pp.53–56. Also see Max Herrera, Arabic Influences in Aquinas’s Doctrine of Intelligible Species, doctoral dissertation, Marquette University, 2010, 86-92.

18 Avicenna, De Anima 5.5, Rahman, ed., 235:  فالخيالات التى هى معقولات بالقوة تصير معقولات بالفعل لا آنفسها بل ما يلتقط عنها . Imaginabilia vero sunt intelligibilia in potentia et fiunt intelligibilia in effectu, non ipsa eadem sed quae excipiuntur ex illis. Latin,Van Riet, ed. v. 2, 128.56-58.

19 In his Metaphysics of the Shifâ’ Avicenna makes his famous distinction of the three ways quiddity can exist: in things, in the soul or absolutely. Ibn Sînâ, al-Shifâ’. Al-Ilâhiyyât, v. 1, 31; Latin, Van Riet ed., v. 1, 35; Avicenna, The Metaphysics of The Healing, Michael E. Marmura, tr. (Provo, Utah: Brigham Young University Press, 2005), 24.  In his De Anima Avicenna says that the formation of universal intelligible intentions altogether separate from matter is the most proper characteristic of human beings.  وأخص الخواص بالإنسان تصور المعانى الكلية العقلية المجردة عن المادة De Anima 5.1, Rahman, ed., 206. Quae autem est magis proprie ex proprietatibus hominis, haec est scilicet formare intentiones universales intelligibiles omnino abstractas a materia. Van Riet, ed., 5.1, v.2, 76.5-6.  In De anima 5.2 Avicenna provides a series of arguments establishing that the receptive subject of intelligible forms must be an immaterial substance. See De Anima 5.2, Rahman, ed., 209 ff.; Latin, Van Riet, ed. v. 2, 81 ff.

20 My translation of the Arabic text. بل كما أن الأثر المتأدى بواسطة الضوء من الصور المحسوسة ليس هو نفس تلك الصور  بل شيء آخر مناسب لها يتولد الضوء فى القابل المقابل كذلك النفس الناطقة إذا طالعت تلك الصور الخيالية واتصل بها نور العقل الفعال ضربا من الاتصال استعدت لأن تحدث فيها ضوء العقل الفعال مجردات تلك الصور عن الشوائب  De Anima 5.5, Rahman, ed., 235-6.  The Latin is a bit mixed up and has: immo sicut operatio quae apparet ex formis sensibilibus, mediante luce, non est ipsae formae sed aliud quod habet comparationem ad illas, quod fit mediate luce in receptibili recte opposito, sic anima rationalis cum coniungitur formis aliquo modo coniunctionis, aptatur ut contingant in ea ex luce intelligentiae agentis formae nudae ab omni permixione. Latin,Van Riet, ed. v. 2, 128.58-63.

21 Avicenna’s views on this and related matters are discussed by Jon McGinnis in ch. 4-5 of his Avicenna, Oxford University Press 2010. There McGinnis also argues for a very different understanding of Avicenna on intelligibles, while the account I offer here accords with the traditional understanding. Since my primary concern is with Aquinas here, the novel interpretation of Avicenna set forth in that book is something I will address elsewhere.

22 LCDA {387-388}; Taylor tr., 304-305.

23 All the quoted translations in this paragraph are drawn from In 2 Sent. d. 17, q. 2, a. 1, ad 3. Averroes has a fundamentally different understanding due to his commitment to the unity of science and knowledge in a single set of intelligibles in act in the separately existing but shared Material Intellect. See the text to which I refer in the preceding note.

24 Avicenna, Al-Ilâhiyyât, v. 2, 5.1, 205-6: وهذه الصورة وإن كانت بالقياس إلى الأشخاص كلية ، فهى بالقياس إلى النفس الجزئية التى انطبعت فيها شخصية ، وهى واحدة من الصور التى فى العقل . ولأن الأنفس الشخصية كثيرة بالعدد ، قيجوز إذن أن تكون هذه الصورة الكلية كثيرة بالعدد من الجهة التى هى بها شخصية ; Haec autem forma, quamvis respectu individuorum sit universalis, tamen, respectu animae singularis in qua imprimitur, est individua ; ipsa enim est una ex formis quae sunt in intellectu, et quia singulae animae sunt multae numero, tunc eo modo quo sunt particulares habebunt ipsae aliud intellectum universale. Latin, Van Riet, ed., v. 2, 238. “This form, although a universal in relation to individuals, is an individual in relation to the particular soul in which it is imprinted, being one of the forms of the mind. And, because individual souls are numerically many, it is possible for this universal form to be numerically many from the aspect that it is individual.” Marmura tr., 157.  As Van Riet notes, the Latin suffers from an omission here. Still, Aquinas is able to take from this passage the view of Avicenna that the universal is received in a plurality of individual human souls or intellects without losing its nature as an intelligible.

25 Avicenna, Al-Ilâhiyyât, v. 2, 5.2, 209: إنما تعرض الكلية لطبيعة ما إذا وقعت فى التصور الذهنى; universalitas enim non accidit naturae alicui, nisi cum ceciderit in formatione intelligibili. Latin, Van Riet, ed. v.2, 241; “. . . universality occurs to some nature if [such a nature] comes to exist in mental conception.” Marmura tr., 159.

26 Aquinas follows the reasoning of Avicenna regarding the knowledge existing in separate substances to establish the notion that intelligibles received into an immaterial substance are not contracted to particularity when he writes, “Nor is it necessary that every singular being be intelligible in potency alone, as is clear concerning separate substances.” Nec oportet omne singulare esse intelligibile tantum in potentia, sicut patet de substantiis separatis, set in illis que indiuiduantur per materiam, sicut sunt corporalia. The source for this is the following. وكانت هذه الصورة هى ما يحصل عن تجريد الحيوانية عن أى خيال شخصى مأخوذ عن موجود من خارج أو جارٍ مجرى الموجود من خارج ، إن لم يوجد هو بعين من خارج ، بل اخترمه الخيالوهذه الصورة وإن كانت بالقياس إلى الأشخاص كلية ، فهى بالقياس إلى النفس الجزئية انطبعت فيها شخصية ، وهى واحدة من الصور التى فى العقل . ولأن الأنفس الشخصية كثيرة بالعذذ ، فيجوز إذن أن تكون هذه الصورة الكلية كثيرة بالعدد من التى هى شخصية ، ويكون لها معقول كلى آخر هو بالقياس إلى مثلها إلى خارج ، يتميز فى النفس عن هذه الصورة التى هى كلية بالقياس إلى خارج بأن تكون مقولة علىها وعلى غيرها Avicenna, Al-Ilâhiyyât, v. 2, 5.1, 205-6; Ergo haec forma est quae acquiritur de exspoliatione animalitatis a qualibet imaginatione individuali accepta de esse extrinseco, quamvis ipsa non habeat esse extrinseco, sed imaginatio abstrahit eam. Haec autem forma, quamvis respectu individuorum sit universalis, tamen, respectu animae singularis in qua imprimitur, est individua; ipsa enim est una ex formis quae sunt in intellectu, et quia singulae animae sunt multae numero, tunc eo modo quo sunt particulares habebunt ipsae aliud intellectum universale, quod in tali comparatione est ad ipsas in quali est ad extra, et discernitur in anima ab hac forma quae est universalis comparatione sui ad extra quae praedicatur de illis et de aliis. Latin, Van Riet, ed., v. 2, 238. “This form is what is realized as a result of abstracting animality from any particular image, taken either from an external existent or from something that plays the role of an external existent-even if it itself does not exist externally but [is something] the imagination invents.   This form, although a universal in relation to individuals, is an individual in relation to the particular soul in which it is imprinted, being one of the forms in the mind. And, because individual souls are numerically many, it is possible for this universal form to be numerically many from the aspect that it is individual. There would be another universal intelligible for it, standing in relation to it, as it stands in relation to what is external. [The universal intelligible] differs in the soul from this form that is universal with reference to what is external in that it is predicable of [itself] and of another.” Marmura, tr., 156-7. Hence, if immaterial separate substances or intelligences can receive intelligibles without contracting them to particulars, the same is the case for the immaterial rational soul on the view of Aquinas. For Averroes, however, the separate substances causing the movement of the heavens are intellects but they have no receptive potency. They have no senses and do not have abstractive knowledge of the world below; nor do they receive intelligibles in act by some efficient causality on the part of God. Rather, for Averroes there is no efficient causality among immaterial entities and God acts only as a final cause which is thereby also only equivocally a formal of the universe and efficient cause of those immaterial intellects, the bodies of the heavens, and the world below. Language of potency used by Averroes in his Long Commentary on the  Metaphysics of Aristotle as well as the language of efficient causality there merely describe the ontological dependency of all lower things on the perfect actuality of being found in the First Principle and First Cause. This is what people commonly call God.  For discussion of these issues, see “Averroes’ Philosophical Conception of Separate Intellect and God,” in La lumière de l’intellect : l’oeuvre scientifique et philosophique d’Averroès, Actes du colloque de la SIHSPAI à Cordoue, à paraître aux éditions Peeters, Leuven, forthcoming.  Also forthcoming in the Proceedings of the Society for Medieval Logic and Metaphysics. See

27 . . . [I]n intellectu vero humano similitudo rei intellectae est aliud a substantia intellectus, et est sicut forma ejus; unde ex intellectu et similitudine rei efficitur unum completum, quod est intellectus in actu intelligens; et hujus similitudo est accepta a re. Mandonnet (1929) p.113.

28 Cum ergo dicimus quod natura universalis habet esse in his sensibilibus, non intelligimus quod ex hoc quod est universalis, scilicet secundum hunc modum universalitatis, sed intelligimus quod natura cui accidit universalitas habet esse in istis signatis. Ergo ex hoc quod est natura est quiddam; et ex hoc quod ipsa est apta intelligi forma universalis est quiddam . . . .

Avicenna, Metaphysics 5.2, Van Riet, ed., v. 2, 244, فإذا قلنا :إن الطبيعة الكلية موجودة فى الأعيان فليسا نعنى ، من حيث هى كلية بهذه الجهة من الكلية ، بل نعنى أن الطبيعة التى تعرض لها الكلية موجود فى الأعيان. فهى من حيث هى طبيعة  شيء ؛ ومن حيث هى محتملة لأن تعقل عنها صورة كلية شيء Anawati and Zayed, eds. v.2, 211;   “If we then say that the universal nature exists in external things, we do not mean in as much as it is universal in this mode of universality; rather, we mean that the nature to which universality occurs exists in things external [to the mind].  Hence, inasmuch as it is a nature, this is one thing; and, inasmuch as it is something from which it is likely that a universal form is intellectually apprehended, it is something else.” Marmura tr., 161.

29 See note 3 above.

30 For Aquinas the species generated thanks to the power of agent intellect in the soul are that by which the natures of things are known and are not themselves directly the objects of knowing. This is made very clear later in his career at Summa theologiae, prima pars, q. 85, a. 2, resp.  In the response to the first objection his view is clearly stated: Ad primum ergo dicendum quod intellectum est in intelligente per suam similitudinem. Et per hunc modum dicitur quod intellectum in actu est intellectus in actu, inquantum similitudo rei intellectae est forma intellectus; sicut similitudo rei sensibilis est forma sensus in actu. Unde non sequitur quod species intelligibilis abstracta sit id quod actu intelligitur, sed quod sit similitudo eius. “To the first it should therefore be said that what is understood is in the knower through a likeness. And in this way it is said that which is understood in act is the intellect in act, insofar as the likeness of the thing understood is the form of the intellect, just as the likeness of the sensible thing is the form of the sense in act. Hence, it does not follow that the abstracted intelligible species is that which is understood in act, but that its likeness is.” See note 18 for the text of Avicenna setting out his understanding of representational forms in the soul which refer to the forms found primarily in the Agent Intellect.

31 See note 18 for the text.

32 In his Letter on the Intellect, al-Fârâbî writes regarding intelligibles in act, وصار هذه المقولات او كثير منها يفهم معانيها فيها على انحاء اخر غير تلك الانحاء مثال ذلك الاين المفهوم فيها فانك اذا تامات معنى الاين فيها اما ان لا تجد فيها شيئا من معانى الاين اصلا واما ان تجمل اسم الاين يفهمك فيها معنى اخر وذلك المعنى على نحو اخر  Alfarabi. Risalah fî al-caql, Maurice Bouyges, S.J., ed. (Beyrouth: Dar el-Machreq Sarl, 1983, 2nd ed.), 17.4-8. “The meanings of these categories themselves or many of them have come to be understood in regard to them in ways other than those ways. For example, with respect to place in regard to these [intelligibles], if you consider the notion of place in reference to them either none of the notions of place exists in them at all, or when you use the name ‘place’ a different notion is understood by you in reference to them, and this notion is according to another way.” For a discussion of intelligibles and abstract in al-Fârâbî, see Richard C. Taylor, “Abstraction in al-Fârâbî,” Proceedings of the American Catholic Philosophical Association 80 (2006) 151-168.

33Avicenna, De Anima 5.6, Arabic, 245:  وقد قلنا إن بدنها وما يتعلق ببدنها مما لا يصلح لذلك إذ لم يصلح أن يكون محلا للمعقولات ولا صلح أن تكون الصور العقلية ذات وضع ، وكان اتصالها بالبدن يجعلها ذات وضع ، وإذا صارت فى البدن ذات وضع بطل أن تكون معقولة

“However, we already said that the body of these and what depends on body from among these is not fitting for this, since it is not fitting that it be the subject of intelligibles, nor is it fitting that intelligible forms have place, and the conjoining of these with the body makes these have place. If they come to be in body having place, this falsifies their being intelligibles.” My translation of the Arabic. Iam autem diximus quod corpus earum et quod pendet ex corpore earum non est dignum ad hoc, nec est dignum ut sit subiectum intelligibilium, quia non est dignum ut formae intellectae sint habentes situm, sed coniunctio earum cum corpore faciet eas habere situm ; si autem essent in corpore habentes situm, non essent intelligibiles. Van Riet, ed., v. 2, p.146.

34 At De Anima 1.5, Avicenna states that this comes about through a conjoining ( نوعا من الاتصال  Rahman, ed., 50; aliquo modo coniunctionis, Van Riet, v.1, 98-99) with an external intellect which is in act, that is, the Agent Intellect.

35 Avicenna, De Anima, 5.5, فإن القوة العقلية إذه اطلعت على الجزٸيات التى فى الخيال وأشرق عليها نور العقل الفعال فينا الذى ذكرناه استحالت مجردة عن المادة وعلائقها وانطبعت فى النفس الناطقة لا على أنها أنفسها تنتقل من التخيل إلى العقل منا ولا على أن المعنى المغمور فى العلائق  ـ   وهو فى نفسه واعتباره فى ذاته مجرد  ـ  يفعل مثل نفسه ، بل على معنى أن مطالعتها تعد النفس لأن يفيض عليها المجرد من العقل الفعال Rahman, ed., 234-35; Virtus enim rationalis cum considerat singula quae sunt in imaginatione et illuminatur luce intelligentiae agentis in nos quam praediximus, fiunt nuda a materia et ab eius appendiciis et imprimuntur in anima rationali, non quasi ipsa mutentur de imaginatione ad intellectum nostrum, nec quia intentio pendens e.g. multis (cum ipsa in se sit nuda considerata per se), faciat similem sibi, sed quia eg consideratione eorum aptatur anima ut emanet in eam ab intelligentia agente abstractio. Van Riet, ed., v. 2, 127. In De Anima, 5.6, Avicenna considers whether the forms known are self-subsistent and the soul acts as a mirror for them or whether the forms emanate into the soul from the Agent Intellect when the soul has intellectual understanding. He opts for the second and explains his view using the metaphors of both emanation and conjunction. فبقى أن يكون القسم الصحيح هو القسم  الأخير ، ويكون التعلم طلب الاستعداد التام للاتصال به حتى يكون منه العقل الذى هو البسيط ، فتفيض منه الصور مفصلة فى النفس بتوسط الفكرة Rahman, ed.,  246-7; Restat ergo ut ultima pars sit vera, et ut discere non sit nisi inquirere perfectam aptitudinem coniungendi se intelligentiae agenti, quousque fiat ex ea intellectus qui est simplex, a quo emanent formae ordinatae in anima mediante cogitatione. Van Riet, ed., v. , 148-9. For a short account of the importance of internal senses in the Arabic / Islamic tradition, including Avicenna, see Alfred L. Ivry, “Arabic and Islamic Psychology and Philosophy of Mind,” in The Stanford Encyclopedia of Philosophy, Edward N. Zalta, ed., URL = First published April 18, 2008.

36 Avicenna, De Anima, 5.6, فيكون الاسفعداد قبل التعلم ناقصا والاستعداد بعد التعلم تاما ، فإذا تعلم يكون من شأنه أنه إذا خطر بباله ما يتصل بالمعقول المطلوب وأقبلت النفس على جهة النظر ـ  وجهة النظر هو الرجوح إلى المبدأ الواهب للعقل  ـ  اتصال به ، ففاضت منه قوة العقل المجرد الذى يتبعه فيضان التفصيل ، و إذا أعرض عنه  عتدت فصارت تلك الصورة بالقوة ولكن قوة قريبة

Rahman, 247-48; Aptitudo autem quae praecedit discere est imperfecta; postquam vero discitur est integra. Cum enim transit in mentem eius qui discit id quod cohaeret cum intellecto inquisito et convertit se anima ad inspiciendum (ipsa autem inspectio est conversio animae ad principium dans intellectum), solet anima coniungi intelligentiae et emanat ab ea virtus intellectus simplicis, quem sequitur emanatio ordinandi. Si vero avertitur a primo, fiunt ipsae formae in potentia, sed potentia proxima. Van Riet, ed., v. 2, 149.

37 See note 17.

38 For discussion of this, see Richard C. Taylor, “Abstraction in al-Fârâbî,” Proceedings of the American Catholic Philosophical Association 80 (2006) pp. 151-168.

39 Taylor tr., 350-51. Modo dat modum ex quo oportuit ponere in anima intelligentiam agentem. Non enim possumus dicere quod proportio intellectus agentis in anima ad intellectum generatum est sicut proportio artificii ad artificiatum omnibus modis. Ars enim imponit formam in tota materia absque eo quod in materia sit aliquid existens de intentione forme antequam artificium fecerit eam. Et non est ita in intellectu; quoniam, si ita esset in intellectu, tunc homo non indigeret, in comprehendendo intelligibilia, sensu neque ymaginatione; immo intellecta pervenirent in intellectum materialem ab intellectu agenti, absque eo quod intellectus materialis indigeret aspicere formas sensibiles. Neque etiam possumus dicere quod intentiones ymaginate sunt sole moventes intellectum materialem et extrahentes eum de potentia in actum; quoniam, si ita esset, tunc nulla differentia esset inter universale et individuum, et tunc intellectus esset de genere virtutis ymaginative. Unde necesse est, cum hoc quod posuimus quod proportio intentionum / ymaginatarum ad intellectum materialem est sicut proportio sensibilium ad sensus (ut Aristoteles post dicet), imponere alium motorem esse, qui facit eas movere in actu intellectum materialem (et hoc nichil est aliud quam facere eas intellectas in actu, abstrahendo eas a materia). LCDA {438-39}.

40 At De Anima 3.5, 429a13, Aristotle states that these must be ἐν τῇ φυχῇ “in the soul,” with the result that “in” comes to be understood in widely varying senses with the dominant view in the Greek and Arabic tradition understanding that the separately existing Agent Intellect is somehow present to the human soul in intellectual understanding. This phrase is used by Averroes at  LCDA {390}; {406}; {437}; and {438}. See the texts in note 41.

41 Taylor, tr. , 351-2.   Et fuit necesse attribuere has duas actiones anime in nobis, scilicet recipere intellectum et facere eum, quamvis agens et recipiens sint substantie eterne, propter hoc quia hee due actiones reducte sunt ad nostram voluntatem, scilicet abstrahere intellecta et intelligere ea.  Abstrahere enim nichil est aliud quam facere intentiones ymaginatas intellectas in actu postquam erant in potentia; intelligere autem nichil aliud est quam recipere has intentiones. Cum enim invenimus idem transferri in suo esse de ordine in ordinem, scilicet intentiones ymaginatas, diximus quod necesse est ut hoc sit a causa agenti et recipienti. Recipiens igitur est materialis, et agens est efficiens.   LCDA {439}. This notion of abstraction as a transference of the intelligible in potency to a different mode of being, namely, the mode of being of an immaterial intelligible in act, is referenced by Aquinas also in the Summa theologiae, prima pars, q.85, a.1, ad 3, where he writes, Sed virtute intellectus agentis resultat quaedam similitudo in intellectu possibili ex conversione intellectus agentis supra phantasmata, quae quidem est repraesentativa eorum quorum sunt phantasmata, solum quantum ad naturam speciei. Et per hunc modum dicitur abstrahi species intelligibilis a phantasmatibus, non quod aliqua eadem numero forma, quae prius fuit in phantasmatibus, postmodum fiat in intellectu possibili, ad modum quo corpus accipitur ab uno loco et transfertur ad alterum. “But by virtue of the agent intellect there results a certain likeness in the possible intellect from the reversion of the agent intellect on the phantasms. This [likeness] is representative of those things of which they are the phantasms only with regard to the nature of the species. In this way the intelligible species is said to be abstracted from the phantasms, not [such] that some form same in number which was in the phantasms after comes to be in the possible intellect, in the manner by which a body is taken from one location and transferred to another.” The notion that intellectual abstraction and understanding come about by our will (ad nostram voluntatem) is derived from his reading of Themistius.  Themistius, Arabic (1974), p. 179.9-12:  فقياس الصناعة عند الهيولى هو قياس العقل الفاعل عند العقل بالقوة  وبهذا الوجه العقل يصير كلّ شيء والعقل يعقل كلّ شئ . ومن قبل ذلك صار إلينا أن نعقل متى شئنا بأنّ العقل الفعّال ليس هو خارجا عن العقل بالقوّة كما أنّ الصناعة خارجة عن الهيولى

Note that here Lyons reads وبهذا الوجه العقل يصير كلّ شيء والعقل يعقل كل شيء  However, I understand يعفل (understands) to be a mistake for يفعل (makes) and translate according to this revision of the printed text. This is a common mistake in Arabic manuscripts. Precisely what Averroes had in his manuscript or just what he understood to be the correct reading is not certain.  While for Themistius the actual intellect comes to exist when the Productive (Agent) Intellect acts on the intellect in potency, in the Middle Commentary Averroes understood actual intellect (al-ʿaql al-fāʿil) and Agent Intellect (al-ʿaql al-faʿʿāl) in this passage both to refer to the Agent Intellect. See Middle Commentary (2002) 117.8-10: وينبغى أن تعلم أن ثامسطيوس وغالب المفسرين يرون أن العفل الذي فبنا مركب من العقل الذي بالقوة ومن العقل الذي بالفعل أعني الفعال.  Themistius, Greek (1899), p. 99.11-14: ὅνπερ οὖν ἡ τέχνη πρὀς τἠν ὗλην λόγον ἔχει, τοῦτον καὶ ὁ νοῦς ὁ ποιητικὀς πρὀς τὀν δυνάμει, καὶ οὗτως ὁ μὲν πάντα γίγεται, ὀ δὲ πάντα ποιεῖ. διὸ καὶ ἐφ᾽ ἡμῖν νοεῖν ὅταν βουλώμεθα· οὐ γὰρ ἔξωθεν τῆς ὕλης ἡ τέχνη . . . .  Themistius, English (1996), p. 123: “So the status that a craft has in relation to its matter is the same as that the productive intellect also has to the potential [intellect], and in this way the latter becomes all things, while the former produces all things.  That is why it is also in our power to think whenever we wish; for <the productive intellect> is not outside <the potential intellect as> the craft <is outside> the matter . . . .”

42 See note 15.

43 See Richard C. Taylor, “Intellect as Intrinsic Formal Cause in the Soul according to Aquinas and Averroes,” in The Afterlife of the Platonic Soul. Reflections on Platonic Psychology in the Monotheistic Religions, Maha El-Kaisy Friemuth and John M. Dillon, ed. (Leiden: Brill, 2009), pp. 187-220. In the Long Commentary on the De Anima, Averroes says that propalavit Aristoteles quod intellectus agens existit in anima nobis: “Aristotle insisted that the     agent intellect exists for us in the soul” at LCDA, 390; and oportuit ponere in anima intelligentiam agentem: “it was necessary to assert the agent intelligence to be in the soul” at LCDA, 438. He asserts that the Agent Intellect and the Material Intellect are in the soul when he writes opinandum est, quod iam apparuit nobis ex sermone Aristotelis, quod in anima sunt due partes intellectus, quarum una est recipiens, cuius esse declaratum est hic, alia autem agens, et est illud quod facit intentiones que sunt in virtute ymaginativa esse moventes intellectum materialem in actu postquam erant moventes in potentia, ut post apparebit ex sermone Aristotelis: “one should hold the opinion which already was apparent to us from the account of Aristotle, that in the soul there are two parts belonging to the intellect, one is the recipient whose being is explained here, the other is the agent which is what makes the intentions which are in the imaginative power to be movers of the material intellect in act after they were movers in potency, as will be apparent later from the account of Aristotle” at LCDA, 406; and also when he writes cum necesse est inveniri in parte anime que dicitur intellectus istas tres differentias, necesse est ut in ea sit pars que dicitur intellectus secundum quod efficitur omne modo similitudinis et receptionis, et quod in ea sit etiam secunda pars que dicitur intellectus secundum quod facit istum intellectum qui est in potentia intelligere omne in actu: “Since those three differences must be found in the part of the soul which is called intellect, it is necessary that there be in it a part which is called intellect insofar as it is made everything by way of likeness and reception. There must also be in it a second part which is called intellect insofar as it makes that intellect which is in potency to understand everything in act” at LCDA, 437.

44 This intellect in a positive disposition is the theoretical intellect or the actual intellectual understanding taking place in the individual human being thanks to the involvement of the separate intellects. Et | ponit quod intellectus agens non se habet ad possibilem 225 ut forma eius set ut artifex ad materiam, et species intellecte | abstracte a fantasmatibus sunt sicut forma | intellectus possibilis, ex quibus duobus efficitur intellectus | in habitu.

45 See the article cited in note 43.

46 See the article cited in note 43 and also Mahoney, Edward P.  “Aquinas’s Critique of Averroes’ Doctrine of the Unity of the Intellect,” in Thomas Aquinas and His Legacy, David M. Gallagher, ed., pp. 83-106. Washington, D.C., The Catholic University of America Press, 1994.

47 On this see the forthcoming article cited in note 15. Also see the discussion in the introduction to LCDA, Taylor, tr.

48 See the work of Wisnovsky cited in note 9.

49 In 2 Sent., d. 17, q. 2, a.1, resp. Et ideo anima habet uirtutem per quam facit species sensibiles | esse intelligibiles actu, que est intellectus agens, | et habet uirtutem per quam est in potentia ut efficiatur 355 in actu determinate cognitionis a specie rei sensibilis | facta intelligibili in actu; et hec uirtus uel potentia | dicitur intellectus possibilis. Et harum duarum uirtutum | operationes sequitur omne nostrum intelligere, tam principiorum | quam conclusionum.  “For this reason the soul has a power by which it makes sensible species to be intelligible [species] in act, and this power is the agent intellect. And [the soul] has a power by which it is in potency for being made in the act of determinate knowing brought about by the species of a sensible thing made intelligible in act, and this power or potency is called possible intellect.  Upon the operations of these two powers follows all our understanding, both of principles as well as of conclusions.”