Alexander of Aphrodisias and the Active Intellect as Final Cause

1 Moraux’s Challenges

Alexander of Aphrodisias is known for his identification of the “active” (ποιητικόν) intellect in De anima III 5 with the prime mover in Metaphysics Λ. In his own De anima, Alexander claims:

Furthermore, if such an intellect is the First cause, which is the cause and principle of being for all the rest, it will also be active in the sense that it itself is the cause of being for all the things that are thought. (DA 89.9–11)^[1]

Some scrupulous readers have raised doubts about this identification of the active intellect with the prime mover.^[2] However, in the rest of the corpus, the phrases “πρῶτον αἴτιον” or “πρώτη αἰτία” undeniably refer to the prime mover.^[3] In the passage above, the position is admittedly expressed in a conditional clause followed by a main clause with the verb in the optative mode. But in this case, the optative mode does not formulate a gratuitous hypothesis disregarding reality. Rather, as it is frequently the case in Alexander’s argumentation, this construction is merely a euphemistic phrasing. The sentence immediately following (καὶ ἔστιν ὁ τοιοῦτος νοῦς χωριστός … 89.11) goes back to the indicative mode and leaves no place to doubt: the active intellect is the First cause and it does indeed exist.

Alexander’s interpretation has a strong general argument to support it: Aristotle ascribes to the intellects of DA III 5 and Metaphysics Λ the same properties, so that it would be inconceivable for two very similar entities to coexist in the philosopher who invented (the so-called) Ockham’s razor.^[4] The problem raised by Alexander’s claim is the following: why would this divine intellect come in the middle of a physical study of soul in general and of human intellection in particular? This objection was already raised by Ammonius: he is reported to have denounced Alexander for saying that “the third thing signified by ‘intellect’ is the actual intellect from outside (τὸν θύραθεν κατ′ ἐνέργειαν νοῦν), which is, in a word, God”, because Aristotle “has not entered upon a theological treatise, and besides, the discussion now is about that intellect which is part of the soul.”^[5] In other words: what is the purpose of the active intellect for Alexander? As Paul Moraux asks in his pioneering work on Alexander’s conception of the intellect, is it not merely a “useless addition”?^[6] In the following, I will call this difficulty ‘Challenge A’. In fact, this question already arises for the readers of Aristotle’s text. Victor Caston has given it a striking formulation when he asked whether our comprehension of DA III 4–8 would be deeply changed if we had lost chapter III 5. (Caston’s answer is no.)^[7] While we would expect from Alexander a resolution of the difficulties of Aristotle’s text, his own De anima seems to reproduce the uncertainties of its source.

In Alexander, the main reason for this problem is that before the active intellect is introduced at 88.17, the account of the development of human intellection can seem satisfying and sufficient. As a brief reminder, in the pages leading to 88.17, Alexander distinguished different degrees of intellect. The intellect which is in pure potentiality is innate and present in (almost) all human beings.^[8] This “material intellect” is nothing but our “aptitude to receive the forms” (84.24–25). It is then comparable to matter and is, for human beings, the simple possibility of rationality. It is not even akin to a blank writing tablet, but more so like the blankness itself of the tablet.^[9] To a certain extent, this pure capacity of thought actualizes itself naturally through induction in most human beings. Thence appears what Alexander calls the “common intellect” (82.14–15) – an expression already used by Epictetus in a similar context.^[10] The next stage, differently, requires a specific effort. This degree of intellect is one which “is acquired in addition” (81.14–15 and 19); it is the intellect “ὡς ἕξις”, ‘as a disposition’ or, for lack of a better term, the dispositional intellect. This intellect is both a resource of universal concepts and the capacity to think for oneself, since it can actualize itself on its own.^[11]

This narrative of the development of the human intellect is evidently based on the Aristotelian doctrine of the three degrees of potentiality and actuality – which is sometimes called the “Triple scheme”.^[12] Aristotle’s text itself leads Alexander there.^[13] But Alexander recasts this narrative using expressions emblematic of his own doctrine, notably the concept of “perfection” (τελειότης), which allows him to depict the development of intellect as an achievement of humanity in human beings.^[14] This intellectual progress corresponds to the maturation of a human being who acquires knowledge throughout his life, both through induction (85.20–25) and through learning (81.25). This theory seems to give a rather intuitive view of the mechanisms of human thought (and one which is in some agreement with contemporaneous theories).^[15] Why then introduce active intellect?

To answer this question, scholars have investigated the following path: holding that Alexander’s depiction of the development of human intellect was not as satisfying as it seemed. Alexander’s theory would contain a difficulty, i.e. how can the material intellect start to think? If the forms are intelligible in potentiality in the sensible things^[16] and if the material intellect is a pure power of thought, then the thought process will never have been able to start on its own.^[17] It lacks a trigger. This problem – let us call it ‘Challenge B’ – will remind one of Meno’s Paradox. But it is not only an issue for modern readers; it was already a problem for ancient Peripatetics, as the short treatise De intellectu in the Mantissa shows. Due to the specific problems of this text (e.g. its authorship), which would deserve a separate discussion, I will not say much about it in this paper. But it is worth noting that De intellectu raises the issue of “double potentiality”^[18] in the same way. The issue is discussed in a section reporting on a tradition which seeks precisely to explain why it is necessary to introduce the intellect “from outside”, that is active intellect.^[19] In Alexander’s De anima, the problem is exacerbated by formulas which seem to make material intellect the subject of cognitive operations, such as abstracting forms from matter.^[20] The dispositional intellect is said to arise in material intellect from a grasping of the universal (ἔκ τε τῆς τοῦ καθόλου περιλήψεως, 85.12), which grasping seems to be performed only by material intellect itself, since it is what produces the dispositional intellect.^[21] This has been described by Paul Moraux as a “blatant contradiction in Alexander’s system”.^[22]

To avoid the inconsistency, the main solution has been to follow the De intellectu, i.e. to refer to the active intellect, on the grounds that only an entity in actuality can trigger actualization of the power of thinking.^[23] The human material intellect should first refer to the divine intellect before it can have an episode of regular thought, as much as our perceptive capacity is actualized by some perceptible object in actuality. But since the material intellect is purely potential and passive, one should then admit that it is the active intellect itself which intervenes directly with the material intellect to trigger its ordinary working.^[24] Proponents of this reading have thus sought to solve Challenges A and B at the same time.

This interpretation can be supported by three texts: (i) the De intellectu;^[25] (ii) Alexander’s reference in his De anima to the famous “intellect coming from outside” in On the Generation of Animals;^[26] (iii) a passage from the De anima where Alexander clearly states that the active intellect is responsible for the acquisition of a disposition by the material intellect.^[27]

As I said above, I will leave the De intellectu aside not only because of the specific problems it raises,^[28] but also because its relationship with Alexander’s De anima is unclear. It is methodologically safer to interpret the two texts separately rather than to use one to interpret the other. Of the two De anima passages, passage (iii) seems to offer the best argument in favor of the ‘interventionist’ interpretation; I will get back to this central text in a moment.

But let us say upfront that the idea of a direct intervention of active intellect, to ‘enlighten’ the human soul and trigger episodes of thought, seems implausible. Firstly, from 81.16 to 88.17, Alexander describes the development of human intellect without relying explicitly on the active intellect.^[29] Secondly, as it has already been pointed out,^[30] the interventionist reading implies that material intellect should first be activated by active intellect, and thus that it should think the active intellect before any ordinary episode of thought. However, when describing the development of human thought, Alexander proceeds by gradually reducing its extension. What I have called degrees of intellect are indeed degrees of potentiality and actuality. But they also correspond to different degrees of intellectual development which are less and less common among human beings. Material intellect is possessed by almost every man except for those who are naturally incapacitated.^[31] Dispositional intellect, on the other hand, is said to be found only among educated persons (82.11). Lastly, passage (ii) about the intellect “from outside” insists on the exceptional character of divine intellection.^[32]

One way to counter this objection is to argue that the divine intellect comes by itself to activate the human intellect. But it would necessarily presuppose that the divine intellect thinks some other thing than itself. The First cause is nothing else than an intelligible form in itself and an intellect always in actuality.^[33] If then it should, as a productive cause, intervene directly with human intellect, it could then only have an effect by thinking the human soul. Some texts in the corpus could suggest that the prime mover’s thinking is not limited to itself and that it has knowledge of other beings.^[34] But one can voice some objections against this. Firstly, one must consider the repeated denial (notably against the Stoics) that the prime mover would direct its attention at what is inferior to it.^[35] Secondly, the strategy would then be to introduce the action of providence. But (i) providence is not the result of a direct ‘action’ of the prime mover toward the world; (ii) it does not extend to individuals, but only to species. There can then be no providential action on particular human intellects. Finally, the most constant claim in the corpus indeed restricts the First cause’s intellection to itself.^[36] If therefore the First cause’s thinking cannot be directed at the intellects of particular human beings, then the thesis of a direct intervention by the active intellect to actualize the material intellect earnestly loses much of its appeal.

To tackle Moraux’s Challenge A, one must then scrutinize more acutely the way in which the De anima accounts for the causality of the active intellect. The solution I would like to offer is simple: the active intellect is a final cause. This solution has been suggested in passing,^[37] but it has not been thoroughly explored. This reading – which agrees with Alexander’s ordinary position about the prime mover’s causality – has three other advantages, it seems to me: it accounts for the multiplicity of expressions with which Alexander describes the causality of the active intellect in his DA; it stays clear of the idea of a direct intervention of active intellect with human intellect; it explains why the development of human intellect has been described without direct reference to active intellect (more on this point in Section 4).

2 The Active Intellect as Pure Form

Even if Alexander’s De anima is not a commentary, it frequently reproduces the rhythm of its source. When the active intellect is introduced at 88.17, Alexander follows Aristotle’s text closely in a paraphrase:

T1 Since in all the things that come to be and are constituted by nature, which contain some matter, there is, on one hand, something which is matter in the^[38] considered genus (i.e. that which is potentially all the things in that genus) and, on the other hand, something which produces^[39] the coming to be in the matter of the things of which matter is receptive (as it is evidently also the case in the things which come to be by art, because art is what causes the coming-to-be of the form in the matter), it seems necessary that these differences apply also to the intellect. And since there is some material intellect, there must also be some active intellect, which comes to be the cause of the disposition of the material intellect. (88.17–24)^[40]

This passage follows the structure of DA III 5.430a10–15. It stops just before the mention of light. As is often the case in his paraphrases, Alexander follows the grammatical structure of his textual source, and inserts notes or parenthetical explanatory remarks. The differences between this text and Aristotle’s have already been abundantly highlighted.^[41] Following the current editions of Aristotle’s text, the distinction between agent and patient in nature comes after an “as” (ὥσπερ): “Ἐπεὶ δ’ ὥσπερ ἐν ἁπάσῃ τῇ φύσει …”. This suggests an analogy between what takes place in nature and what takes place in the soul. It has been sometimes believed that the presence of this “as” opened way to a identification of the active with the prime mover, with the idea that, if the case of soul is only analogous to the case of nature in general, it is because the active intellect is itself not “natural”.^[42] Alexander’s example – which ‘divinizes’ the active intellect, but omits the ὥσπερ as coordinator of the analogy – shows that this reasoning is not necessary. His paraphrase in fact supposes a transposition of what manifestly takes place in nature to what takes place between the sublunary and supralunary regions. This transposition is all the more facilitated by another difference with Aristotle’s text. While Aristotle draws a conclusion about what takes place in the soul or what is true in the case of soul (“ἐν τῇ ψυχῇ”), Alexander draws a conclusion about what applies to the intellect. This latter distortion does clearly speak in favor of an identification of the active intellect with the First cause, since it frees the agent/patient distinction from the constraints of the soul.

Before proceeding further, we must bear in mind that Alexander knows the division of the Aristotelian treatises in books, but not their division in chapters. He thus reads continuously what we call chapters III 4 and III 5. In his own De anima, passage T1 is introduced, as in Aristotle, with a simple “δέ”. T1 must then be read in a sequence with the previous lines, which are based on the end of DA III 4. At the end of chapter 4, Aristotle has raised two aporias, one on the impassibility of intellect, the other on the intelligibility of intellect. In the second aporia, Aristotle wonders if the fact that intellect is intelligible implies that all intelligible things be intellects. The solution he sketches (at 430a2–9) involves the distinction of two cases: the objects which are without matter and in which there is a perfect identity between intellect and intelligibility, on the one hand; and the enmattered forms which become intelligible in actuality only through some process and which are not in themselves intellects, on the other hand.^[43] Of these two aporias, Alexander focuses on the second one (87.24–88.16).^[44] He uses it to posit the existence of forms in themselves and separate from matter, where Aristotle speaks only of objects without matter. Alexander then understands the solution to the second aporia as introducing two types of intelligible things – those which are intelligible in themselves and those which are enmattered –, rather than introducing two situations a single kind of intelligible things can be found in. This multiplicity of pure forms has puzzled the commentators.^[45] In fact, the plural comes directly from Aristotle’s text.^[46] What Alexander’s interpretation adds to the ending of III 4 is then the term “form”.^[47] For Alexander, the crucial achievement is that these forms without matter are themselves intellects in actuality and in the utmost manner (88.2–3). Conversely, “intellect is a form separate from matter” (88.15). It is only in this context that we can understand the determination by Alexander of the active intellect as a pure form. This determination of the active intellect is indeed the result of two movements: on the one hand, the depiction of the states of the intellect in terms of matter, perfection and form,^[48] and, on the other hand, a typology of forms.

After having posited the existence of a pure form which is intellect in itself, the T1 passage aims to describe its causal role, as the last sentence of T1 (included at the start of T2 below) shows. This back and forth between what the active intellect is and what it does structures the rest of the passage:

T2 And since there is some material intellect, there must also be some active intellect, which comes to be the cause of the disposition of the material intellect. This will be the form which is properly and supremely intelligible, and such is the form which is separate from matter. For in all cases, that which is supremely and properly x, is what causes other things to be also x. For example, what is supremely visible (and light is this sort of thing) is cause of other visible things’ being also visible. Moreover, what is good supremely and primarily is the cause of the other goods’ being also such. For the other goods are distinguished by their contribution to this. So, what is intelligible supremely and by its own nature will be for good reason the cause of the intellection of the rest. Being such, it will be the active intellect. For if there did not exist something intelligible by nature, nothing else would become intelligible either, as has been said earlier.^[49] For in all cases in which there is, on one hand, something which is properly x,^[50] and, on the other hand, something which is such secondarily, that which is secondarily has its being from that which is properly. Furthermore, if such an intellect is the First cause, which is the cause and principle of being for all the rest, it will also be active in the sense that it itself is the cause of being for all the things that are thought. (88.23–89.11)^[51]

Here Alexander stops paraphrasing, and the text develops more freely. Indeed: before this passage, Alexander was paraphrasing 430a10–15 and, right after this passage (at 89.11–12), he will cover 430a17–18. In other words, this entire passage T2 depends on 430a15–17:

And there is one intellect which is such^[52] because it comes to be all things, and another because it makes all things, as a sort of disposition, like light. For in a way, light makes the things that are potentially colours, colours in actuality. (Aristotle, DA III 5.430a14–17)^[53]

I have given here Aristotle’s text from 430a14 to show how Alexander’s text departs from the paraphrase in the middle of the first sentence. Indeed, this clause in Alexander’s text: “And since there is some material intellect, there must also be some active (poietikon) intellect” is an interpretation of Aristotle’s clause: “And there is one intellect which is such because it comes to be all things, and another because it makes (poiein) all things”. It is right after this that things get rougher.

In Aristotle, “disposition” (hexis) grammatically refers to what is the intellect which “makes all things”. In Alexander, hexis refers to what is produced by the active intellect. Therefore, either Alexander reads a text different from ours; or he has altered the meaning of the text he was reading. The first option would imply an important difference with the text transmitted to us. All ancient commentators after Alexander understand the text as he did, but cite the text as we read it.^[54] The second option is more plausible. Alexander would have displaced hôs hexis tis so as to qualify the way in which material intellect becomes all things under the impetus of active intellect.^[55] Thus his reading involves a hyperbaton: “And there is one intellect which is such because it comes to be all things, as a sort of disposition, and another because it makes all things, like light”. As Donini has rightfully shown, this reading saves the doctrine of the three degrees of the intellect.^[56] What also speaks in favor of the second hypothesis is that the rest of Alexander’s text ruptures with the paraphrastic style and refers more liberally to its source.

In order to explain what the active intellect does, Alexander relies on a principle which is not mentioned in Aristotle’s De anima, but which Alexander plucked from Metaphysics α 1.993b23–31.^[57] To keep things short, this principle can be called the Principle of Maximal Causality (PMC). In Alexander’s interpretation, it states that, among a set of things instantiating a property^[58] φ, what is supremely φ is necessarily cause of being-φ in the rest of the set – as fire, which is maximally hot and cause of heat in other hot things. What the text of the De anima teaches us is that Alexander also endorses the converse of the principle, i.e. a principle which goes from the maximum to causality: in a set of things instantiating a property φ, what is cause of being-φ in the rest of the set must itself be supremely φ.

Indeed, if we schematize the argument (without making explicit the premisses which Alexander presupposes) the first argument of T2 is:

(P1) ‘There must be some active intellect.’ (C) (88.23–24).

(P2) PMC (88.26–89.1).

⸫ ‘This <intellect> will be the form which is properly and supremely intelligible.’ (M) (88.24–25)

(P1) derives directly from the analogy with what happens in nature made right before: if there is a passive intellect, as was asserted earlier, there must be an active intellect. As for the fact that the supremely intelligible form is an intellect, this has been demonstrated in the previous section, where Alexander states that the immaterial form in actuality is necessarily an intellect in actuality (88.1–2 and 15). Through the PMC, this argument thus connects the existence of an active intellect with the immaterial form which has already been introduced (relying on the second aporia at the end of III 4).

But, in the analogies with light and the good, which serve as examples for the PMC, the inference goes from the maximum [M] to causality [C]:^[59]

For example, what is supremely visible [M] (and light is this sort of thing) is cause of other visible things’ being also visible [C]. (89.1–2)

This is why, going back to the intellect, the passage can conclude as follows:

So, what is intelligible supremely and by its own nature [M] will be for good reason the cause of the intellection of the rest [C]. Being such <i.e. supremely intelligible…>, it will be the active intellect. (89.4–6)

What could look like a petitio principii on Alexander’s part is in fact the sign of a ring-composition, triggered by a two-way reading of the PMC: from causality to the maximum, and conversely from the maximum to causality. Alexander’s principle is then more precise than the medieval axiom stating only that the cause is superior or equal to its effect.^[60]

In order to be valid, this principle presupposes that, at least to some extent, the cause and its effects instantiate the same property. This presupposition explains why Alexander departs from Aristotle’s text when he covers the light analogy:

… in a way, light makes the things that are potentially colours, colours in actuality. (Aristotle, DA III 5.430a16–17)

… what is supremely visible (and light is this sort of thing) is cause of other visible things’ being also visible. (Alexander, DA 89.1–2)

In Alexander’s version, colors are no longer explicitly mentioned since they would complicate the PMC’s application. This is likely what also accounts for the change to the Aristotelian theory of light. Aristotle, on his part, never says that light is “supremely visible”.^[61] Thus, before we hurl ourselves at Alexander’s purported “platonization”^[62] of the Aristotelian doctrine, it is better to account for his strategy. Even if Alexander distorts the Aristotelian doctrine of light, he does so because of an interpretation of an Aristotelian passage (Metaphysics α 1), in order to explicate another Aristotelian passage (DA III 5). And, certainly, Aristotle himself had in mind the reference to Plato’s Republic VI.

But, as I have said, the maximum shares its property with the other elements of the set only to a certain extent. The PMC does not require a strict synonymy between the various elements of a given set. Alexander commonly envisions applying the PMC to things said to be ἀφ′ ἑνὸς καὶ πρὸς ἕν.^[63] This is what the case of the Good shows us: classically, in Alexander, the Good is not a synonym.^[64] This would be a first internal explanation accounting for the introduction of the Good, which is absent from Aristotle’s text. Alexander uses the Good to apply the PMC to a set of elements which are not synonymous with each other. But there is more: the case of the Good, differently from the case of light, does not provide only an analogy. Alexander explains elsewhere that the First cause is the supreme Good.^[65] The Good is introduced to indicate how we must understand the causality of the active intellect.

3 What Does the Active Intellect Activate – and How?

As we have seen, the double sense of the PMC explains the text’s back and forth between the active intellect’s causality and its status as a pure form. However, the way in which this causality is described changes progressively in the text. To summarize, there are five formulations according to which the active intellect is:

1. “cause of the disposition of the material intellect” (88.24);

2. “cause of the intellection of other things” (89.5);

3. that without which nothing “would become intelligible” (89.7);

4. “cause and principle of being for all other things” (89.9–10);

5. “cause of the being of all things that are thought” (89.10–11).

The variety of these expressions has puzzled commentators.^[66] The causality of the active intellect seems to apply sometimes to the human intellect (1 and 2), and sometimes to intelligible things or all things in general (3, 4 and 5).^[67] Worse: at 89.4–5, after formulating the PMC and making the two analogies with light and good, Alexander infers that the active intellect is “cause of the intellection of other things” (2). Congruently, one would have expected the active intellect to be said to be “cause of intelligibility”, since it is “properly and supremely a form”. How then can Alexander go from intelligibility to intellection? If we focus on textual consistency and if we admit that the PMC does work in the way I have described above, we must attempt to understand how these statements are compatible, if not equivalent.

Alexander gives us some clues about the causality of the active intellect. The first is in the light analogy. As previously said in the De anima, light is something which “both is supremely visible and becomes a cause to other visible things in that they are seen”.^[68] Indeed, light actualizes the visibility of visible things by actualizing the transparent. This makes possible the connection of what sees with what is being seen. In the same line, Alexander says, “visible” (like “audible” or “tangible”) is not the name of a substrate, but the name of a relation (σχέσις).^[69] Light does not produce the potential visibility of visible things; it enables them to affect us.^[70] Although this is only an analogy, we can legitimately expect active intellect to not produce the potential intelligibility of intelligible things either.^[71]

And indeed: what is the intelligible, i.e. an object of thought? Alexander’s answer in the De anima is unambiguous: it is the forms, be they pure forms without matter or the forms found in compounds. In the case of the hylomorphic compound, to think is to separate form from matter.^[72] The form of a hylomorphic compound remains potentially intelligible as long as it is not thought.^[73] Yet there is no doubt that, for Alexander (who is a dedicated Aristotelian), forms are not produced by the First cause since they are somehow eternal.^[74] This issue is complex (hence my ‘somehow’); yet, whichever kind of eternity we have in mind here, the fact remains that a form cannot be generated, let alone produced. As Alexander summarises in his refutation of Plato’s Timaeus about the generation of natural bodies, “just as there is no generation of matter, so there is no generation of form by itself, but generation is of the two together”.^[75] In addition, we must be wary here of our modern tendency to take “cause of being” to mean “cause of existence”: Alexander uses the expression in a sense which clearly cannot be that of existence many times.^[76] Lastly – as has already been noted^[77] – the analogy with light invites us to see this causality not as a direct production, but as an indirect action.

To understand how the active intellect can exercise its causality on intelligible things, we can now follow the lead of the analogy with the Good. As I have already mentioned (pace P. Accattino and P. Donini), it does not seem to me to be at all the case that the Good would be only another example, neither should we interpret it “nel modo debole” to “preserve” Alexander from Platonism or from the accusation of introducing participation.^[78] In my understanding, the case of the Good works here as a conceptual signpost to signify “final cause”. As Alexander establishes elsewhere, the Good is the final cause which is the principle of all generation and all motion.^[79] Reciprocally, in every substance, the end is the good.^[80] To clear up any misunderstanding, Alexander inserts here the notion of “contribution” (συντέλεια) which shows the end (τέλος):

Moreover, what is good supremely and primarily is the cause of the other goods’ being also such. For the other goods are distinguished by their contribution to this. (89.2–4)

The claim is convoluted. Nonetheless, we can make out that the evaluation of the goodness of a secondary good is done according to its status as a means, aiming at a good in itself. If thus some thing (health, for instance) facilitates access to some end in itself which is good in itself (happiness), then health deserves the predicate “good”.^[81] The case of the Good is here exactly similar to the one of healthy things called thus in virtue of their “contribution” to what is properly healthy, i.e. health itself.^[82]

As is well-known, Alexander interprets elsewhere the causality of the prime mover as that of a final cause. Indeed, the first heaven – the sphere of fixed stars – and, after it, the celestial bodies are set in motion by their desire to imitate the unmoved prime mover.^[83] To say that the unmoved mover is “loved” by all the spheres is to say, for Alexander, that the latter want to become similar to the former.^[84] In this sense, the circular motion of the sphere of fixed stars imitates the immobility of the unmoved prime mover. More generally, this quest for emulation explains the tendency (ἔφεσις) of any substance – including the substances of the sublunary sphere – to actualize its own form, to “perfect” themselves and, for some, to desire immortality,^[85] as if it were drawn towards the First cause by magnetic force.^[86] It is thus a striking feature of Alexander’s interpretation that he assigns God as an end to the entire universe.^[87] All substances are essentially guided by their desire for the Good, which is a sign of finality for the entire cosmos.

For compound substances, this desire is realized in an actualization of their form, through which they can attain to their own good.^[88] As M. Rashed has duly shown,^[89] Alexander distinguishes between a form merely possessed by the compound (hexis) and its fully actualized form. For instance, this is what distinguishes a human being without virtue (who is still a human being) from a virtuous human being, who has reached the perfection and culmination of their nature.^[90] This distinction between two states of form is introduced at the very beginning of the De anima. In the case of simple bodies, this distinction is the one between form as motive power (the power of earth to move downwards, for instance) and the perfection of such power, which is properly ἐνέργεια.^[91] This first perfection – reprising Aristotle’s first entelechy^[92] – is also the one which corresponds to soul, as the principle of its actualization – be it for nutrition, sensation, movement or thinking.

The prime mover is what causes, as an end, the realization of every form, i.e. its transition from first perfection to second perfection, from form merely possessed to form fully achieved. This process of perfection is firmly established by a quotation by Simplicius of Alexander’s Commentary on the Physics:

T3 But insofar as everything achieves its own perfection by aiming at this (as will also be said a little later) and insofar as “it causes motion by being loved” (as he has again said in the Metaphysics) the First cause would also be the goal and the cause “for the sake of which”. (Simplicius, In Phys. 258.20–23, transl. Mueller)^[93]

The interest of this passage lies less in the traditional position ascribed to Alexander (that the first mover moves as a final cause) than in the manner in which this causality is expressed. Alexander’s distinctive terminology is used: each thing tends to its own perfection (teleiotes). Here, this last word necessarily refers to the second perfection, to the full achievement of one own’s form. By adding “own” (oikeios), Alexander claims that substances do not aim directly at the First cause, but that their aim at it is mediated by their desire for their own good.^[94] Alexander is likely not breaking any new ground when making this claim: a passage where Aspasius comments on the first sentence of Nicomachean Ethics already says something similar:

That is how one must understand ‘aiming at’, in the sense that everything is equipped by nature to resemble the most perfect and primary cause as much as possible. For each thing is eagerly drawn by its own nature to its proper perfection. It is drawn to this because it is inclined to that which is most perfect of all. (Aspasius, In EN 4.6–10, transl. D. Konstan modified)^[95]

A precise commentary on this passage would go beyond the scope of this paper. Let us simply remark that the similarities with Alexander are numerous and striking: (i) the conceptual connection between τελειότης and ἐφίεσθαι; (ii) the correlated claim concerning what might be called universal eudemonism – that by nature everything (not just every animal or living thing) “is drawn” to the good; (iii) the idea that such inclination is aimed at the First cause, although this finality must in fact be understood as mediate, as the emphasis on “own” or “proper” (idios) shows.^[96] The First cause is ultimately (but indirectly) that on account of which every form concretely manifests in second actualities:^[97] a plant growing, a stone falling on account of its heaviness, a human being searching for happiness…

However, as the PMC requires, the First cause must be responsible for some sort of actualization of the intelligibility of intelligible things. It is indeed the cause of something happening to intelligible things, as the modus tollens argument sketched in T2 suggests:

For if there did not exist something intelligible by nature, nothing else would become intelligible either. (89.6–7)

The active intellect does not produce potential intelligibles, not anymore than light produces colors. Yet, without light, a potential visible thing, namely a color, could not affect us. Likewise, without active intellect, no potential intelligible thing, i.e. no form, could become manifest through the particular actualities which bring it to achievement. As light is a condition of possibility of sight, the active intellect is what guarantees that human thought may have possible objects.

For what would happen in a world without a First cause being an intellect and an intelligible in the proper sense? In Metaphysics Λ 6–7, Aristotle answers this question using the mythical image of Night (1072a19–20). In Alexander’s terminology, “nothing else would become intelligible either” (89.6–7): no form would tend to reach its second perfection and every form would remain dormant – to use an analogy which Aristotle himself uses for the first actuality.^[98]

Our text T2 summarizes the causality of the active intellect with a formulation echoing Alexander’s commentary to Physics VIII: the First cause is “cause and principle of being for all the rest” (89.9–10).^[99] Indeed, in Alexander’s essentialism, the more some thing is – that is, the more it is what it has to be –, the more intelligibility or “truth” it possesses, as the Commentary on Metaphysics α 1 establishes.^[100] This equation of being and intelligibility, typical of Alexander’s essentialism, is easily understood if we recall that (i) the form is what is intelligible and (ii) every substance is what it is according to its form, which form Alexander commonly calls the “cause of being”.^[101] If the prime mover is the final cause of the achievement of forms, it can then legitimately be said “cause and principle of being for all the rest” (89.9–10), just as well as “cause of the being of all things that are thought” (89.10–11).

For in the case of hylomorphic compounds, a form’s perfection necessarily corresponds to the realization of its essence. In the pages that we are examining now, the De anima uses a quite narrow depiction of thought, namely the intellection of essences. Alexander does not dwell on discursive thinking.^[102] Via the separation of forms from matter, the human intellect gains access to the quiddity of the compound and to the universal.^[103] The intellection of an essence thus corresponds to the recognition of the universality of the essence which was grasped.^[104] But this recognition is only possible since most of compound substances tend by nature to achieve their quiddity. For a substance, to reach achievement is to instantiate, as much as possible, the common and universal nature of which its quiddity consists.^[105]

If Alexander has in mind the final causality of the First cause in the T2 passage, he is then legitimate in claiming that the active intellect is responsible for the being of all things, but also in claiming that the active intellect is that without which no intelligible thing would come to be nor would actualize. The active intellect is not a direct cause of an episode of thought, but that without which no episode of thought could occur, for lack of an object.

But there is more. What is true for any enmattered form is also true for a human being. Not only is the human soul a form, but, in many respects, it is the paradigm of the sublunary forms in general, as the beginning of the DA shows.^[106] Alexander’s pages on the intellect involve the doctrine of the two states of forms and the notion of perfection. The dispositional intellect is said to be the “perfection” of the material intellect.^[107] But, according to Alexander’s full definition, a human being is a mortal and rational animal able to receive intellect and science.^[108] It is then logical that, when he presents the rational faculty of the soul, Alexander emphasizes that it is that through which a human being becomes a more achieved animal (80.23) and that it contributes, not to a human being’s being, but to their good (εὖ εἶναι, 81.16ff.).^[109] The progress of the intellect, described in the next pages, is then also the perfecting of the human being which, in the best of cases, may end up thinking the highest possible object of thought, namely the First cause itself.^[110] But the active intellect is not only the supreme object at the end of the natural development of human intellection; it is also a condition of possibility for that development. The First cause is the final cause of the perfection of any form. It is also responsible for the development of human intellection.

There is thus no contradiction in T2 between the expressions of the causality of the active intellect which focus on objects, and those which assign it responsibility for intellection itself, or for the acquisition of a disposition by the human intellect. But, as we have seen with the Simplicius quotation (T3), it is indeed by aiming for its own perfection that a substance aims, mediately, for the prime mover. There is then no need for the intervention of direct causation of the active intellect on the material intellect of the human being. However, finality is certainly one of the senses of causality – and even, for Alexander, its most eminent sense. He is then legitimate in maintaining that the active intellect “comes to be the cause of the disposition of the material intellect” (88.24).

In other words, the active intellect is twice “cause of the intellection”, i.e. cause of the actualization of human thought: once (i) when it offers thought occasions for thinking through objects, and again (ii) when it actualizes mediately the human intellect itself in its development. The active intellect as final cause thus makes possible the “relation” which thinking is. It is because all forms – both the forms of human souls and every other form – actualize in their mediating tendency toward the prime mover that the former can meet with the latter.

4 Back to Challenge B and Some Objections

The teleological solution I have proposed to answer Moraux’s Challenge A has a flaw: it no longer solves Challenges A and B at the same time – that is, it does not explain how the human intellect can begin to think, since it removes any direct intervention on the part of the First cause. Addressing this issue would require us to carefully pick through pages 83.2–86.6 of Alexander’s De anima. However, I will end by suggesting that the teleological reading I have attempted might shed some light on Challenge B.

The teleological interpretation can explain one of the main objections made against the interventionist reading: it can explain why active intellect is not involved in the account of human intellectual development. That is precisely because human beings, like any substance, aim at the First cause only by aiming at their own good and at the perfection of their own nature. Alexander gives us some indications according to which human beings achieve their proper perfection by actualizing their intellect. First, he describes the actualization of our intellect not as an innate phenomenon but rather as something we have acquired later in life, and this fact, he claims, is the clearest sign that our power of thinking does not contribute to our being, but to our well-being (πρὸς τὸ εὖ εἶναι, 81.16), i.e. to our flourishing and “perfection” (81.20). This point, like the distinction between practical and theoretical intellect,^[111] shows how strong is the influence of the Nicomachean Ethics on Alexander as he writes these pages of his De anima. ^[112] It is no coincidence that Challenge B is so reminiscent of the Aristotelian problem of the acquisition of virtue.^[113] This is not a mere analogy, since becoming virtuous requires us to develop our rationality and our power of thinking,^[114] and since rationality and virtue are said to be the “perfection and culmination” of human beings’ “proper nature”.^[115]

On this path to culmination, Alexander says, man is helped and “guided by nature”, at least up to some point.^[116] Even though at birth we are only equipped with material intellect,^[117] the actualisation of our intellect is also in part natural^[118] and takes place during puberty.^[119] Hence Alexander’s insistence on the gradual emergence of our grasping of the universal from sensible experience. The De anima emphasizes the continuity and even the contiguity of mental states:^[120] our cognitive life has always already begun, so much so that the issue of its very first beginning becomes less relevant. But this is so because the natural inclination of human beings towards their end, as well as the one of his ordinary objects of thought, is ultimately activated by the first final cause and drawn, as if magnetically, to it.

In conclusion, the reading I propose could be met with two objections. The first objection is based on the very name of the “active” intellect. Does the fact that this intellect is called “poietikon” not necessarily require that it exerts efficient causality? However, Alexander is only the inheritor of this wording, which he finds in the Aristotelian text and for which Aristotle is responsible. As such, it is entirely feasible to consider that Alexander misinterprets when he understands the causality of the active intellect as a final causality. But this objection does not invalidate the interpretation I have proposed as far as Alexander is concerned.

Additionally, Alexander sometimes calls the final causality of the prime mover “poietikon”.^[121] This designation comprises two distinct senses: in one – loose – sense, the prime mover’s causality as a final cause is poietikon to the extent that the prime mover produces an effect and triggers motion as a final cause;^[122] in another – more significant – sense, the prime mover is indirectly an efficient cause because it is the final cause of the motions of the first heaven which acts as efficient cause.^[123] But none of this calls into question the substantive thesis: in a strict sense, the prime mover acts solely as a final cause.

A second objection would criticize the reading I have offered on the grounds that it overinterprets the text of Alexander’s De anima. R.W. Sharples has rightfully emphasized how unspecific passage T2 was: “Those who look for a specifically epistemological explanation of the role of the Active Intellect in Alexander’s treatise On the Soul will be disappointed.”^[124] Undeniably, the passage does not stand out because of its clarity or because of its abundance of details. This is on account of the text’s style as a treatise, as Alexander writes it, that is, differently than the style in which he writes his lemmatic commentaries, which are often more technical and more specific. But, since Alexander maintains elsewhere and consistently that the First cause is a final cause, to ascribe another position to him in the De anima would be to introduce a discrepancy in the corpus. Refusing to do so is an act of minimal hermeneutic charity.