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Phantasm-3 and the Intellectus Agens

The analysis of Phantasm-2 and Phantasm-3 provides a hint towards understanding the formation of an intelligible species via the intellectus agens as a means towards the formation of a concept in the intellectus possibilis. There is only time and space here to sketch this possible connection. Nonetheless, the intellectus agens does not form the

conceptus; this is the role of the intellectus possibilis informed by the species intelligibilis abstracted by the intellectus agens from the phantasms stored in the sense memory. In order to see this connection, we need to consider various texts from the Aquinas corpus. Often in Book II of the Summa Contra Gentiles, one finds statements like the following: ‘phantasms [are] prepared by the vis cogitativa in order that they may become actually intelligible and move the possible intellect’ (bk II, ch. 76); ‘The vis cogitativa is [. . .] directed to the possible intellect [the intellectus possibilis] [. . .] only through its act by which the phantasms are prepared, so that by the intellectus agens they may be made actually intelligible; in this way, the possible intellect is perfected’ (bk II, ch. 73). Aquinas brings together all three inner sense faculties of the internal sensorium: ‘It is through the vis cogitativa, together with the imagination and the memory, that the phantasms are prepared to receive the addition of the intellectus agens, whereby they are made actually intelligible’ (bk II, ch. 60). Throughout this discussion in the Summa Contra Gentiles, Aquinas is concerned about the position defended by Averroes asserting that the intellect for human beings is separated from and existentially independent of all human knowing in the space-time realm. While this issue is not a burning one in contemporary philosophy of mind, nonetheless it is in these discussions that Aquinas articulates several useful insights on the relation of phantasm to the intellectus agens.

Brentano was an important commentator on both Avicenna and Aquinas. In discussing Avicenna and his position on the separated nature of the intellectus agens, Brentano suggests an important role for the vis cogitativa. He calls the vis cogitativa, much as Averroes described this internal sense faculty, the virtus cogitativa, which is the ‘sensory thought faculty’. Brentano further argues that the vis cogitativa is needed in order for what Avicenna calls the ‘material intellect’, which is the place in the human knower where concepts are known, to receive forms from the ontologically separated intellectus agens. He writes the following: ‘The activities of the imagination and of the sensory thought-faculty [the virtus cogitativa] are needed to put it [i.e. the material intellect] in a position to combine with the active intelligence and receive the intelligible forms that emanate from the latter.’[1] What is important and significant textually in this passage from Brentano is the role that the vis cogitativa plays in the formation of concepts by the intellectus agens. If the vis cogitativa can recognize individuals of a natural kind, then the active intellect will be far better at abstracting the appropriate species intelligibilis rooted in the substantial form, which in turn produces the basis of concepts in the intellectus possibilis in Aquinas’s philosophy of mind.[2]

Haldane considers the importance of the species intelligibilis:

For Aquinas, the impressed species is a determination of the (possible) intellect in respect of some form F which thereby constitutes the standing state: possession of the concept F, and this acquired conceptual capacity is termed a habitus (i.e. an acquired disposition). The expressed species, by contrast, is an exemplification of the concept evoked in a particular thought. What is produced in the exercise of a concept is a conceptus. That is to say, the conceptus is a mental event the character of which is determined by the expressed species which structures it and which is a particular expression of the abstracted and retained impressed species.[3]

For Aquinas, the result of the abstractive process of the intellectus agens is a species intelligibilis. This acts in a manner like the sensible species, which ‘informs intentionally’ the external sense faculty. The possible intellect is then ready to know the essence, and when it does actually know the essence, the content of the abstracted form serves as a conceptus, which is the means by which the human understanding knows the essential, sortal properties in the individual in the external world. The conceptus is not an object of thought, unless it is reflected upon much like a phantasm is reflected upon by the vis imaginativa. Rather, the conceptus is the means by which a human knower becomes aware of the structure of the external world. This structure, of course, is determined by a substantial form ‘implanted’ or ‘emmattered’ in a piece of matter, which determines the foundation of a natural kind in Aquinas’s Aristotelian ontology. This is rooted fundamentally in the Aristotelian theory of hylomorphism, one that Aquinas accepts almost uncritically.

Why postulate the intellectus agens? In his Compendium of Theology, Aquinas discusses the need for this power of intellect; this extended passage is one of the better published accounts in which Aquinas discusses the intellectus agens as a necessary cognitive condition for the acquisition of human conceptual knowledge of the eternal world:

This discussion brings out the truth that knowledge of things in our intellect is not caused by any participation or influence of forms that are intelligible in act and that subsist by themselves, as was taught by the Platonists and certain other philosophers who followed them in this doctrine. The Platonists, however, are incorrect. The intellect acquires knowledge from sensible objects, through the intermediacy of the senses. However, since the forms of objects in the sense faculties are particular, as we just said, they are intelligible not in act, but only in potency. For the intellect understands nothing but universals. But what is in potency is not reduced to act except by some agent. Hence, there must be some agent that causes the species existing in the sense faculties to be intelligible in act. The intellectus possibilis cannot perform this service, for it is in potency with respect to intelligible objects rather than active in rendering them intelligible. Therefore, we must assume some other intellect, which will cause species that are intelligible in potency to become intelligible in act, just as light causes colors that are potentially visible to be actually visible. This faculty we call the intellectus agens, which we would not have to postulate if the forms of things were intelligible in act, as the Platonists held. (Compendium of Theology, pt I, ch. 83)

In a later part of the Compendium, Aquinas continues this discussion:

The intellectus possibilis is in potency with regard to intelligible objects in the sense that it does not contain within its nature any determinate form of sensible things [i.e. there are no

Cartesian innate ideas]. In the same way, the pupil of the eye is in potency with regard to all colours. To the extent, then, that phantasms abstracted from sensible things are likenesses of definite sensible things, they are related to the intellectus possibilis as act to potency. Nonetheless, the phantasms are in potency with regard to something that the intellectual soul possesses in act namely, being as abstracted from material conditions. And in this respect, the intellectual soul is related to the phantasms as act to potency. No contradiction is involved if a thing is in act and potency with regard to the same object according to different points of view. The same intellectual soul, therefore, can be in potency with regard to all intelligible objects and nonetheless, without any contradiction, can be related to them in act, if both an intellectus possibilis and an intellectus agens are acknowledged in the soul. (ch. 88)

Aquinas continues:

The role of the intellectus agens will be seen more clearly from the way the intellect renders objects actually intelligible. The intellectus agens does not render objects actually intelligible in the sense that the latter flow from it into the intellectus possibilis. If this were the case, we human knowers would have no need of phantasms and sense in order to understand. On the contrary, the intellectus agens renders things actually intelligible by abstracting them from phantasms. In a similar fashion, light, in a certain sense, renders colours actual, not as though it contained the colours within itself, but so far as it confers visibility on them. In the same way, we are to judge that there is a single intellectual soul that lacks the natures of sensible things but can receive them in an intelligible manner, and that renders phantasms actually intelligible by abstracting intelligible species from them. The power whereby the soul is able to receive intelligible species is called the intellectus possibilis, and the power whereby it abstracts intelligible species from phantasms is called the intellectus agens. The latter is a sort of intelligible light communicated to the intellectual soul, in imitation of what takes place among the higher intellectual substances. (ch. 88)

The three powers of the internal sensorium working together prepare the data from sensation and perception for the abstractive work of the intellectus agens. This preparation is so very important for the intellectual life of human beings that Averroes once suggested that the vis cogitativa should be called a kind of ‘intellect’. The vis cogitativa is sometimes referred to as the ‘particular reason’.[4]

Aquinas often writes about the close working relationship between the intellective powers and the internal sensorium. In the Summa Theologiae, he writes that the intellect has need of certain ‘lower powers’ for its mental acts to function well: ‘The lower powers of which the intellect has need in its operation. For those in whom the imaginative power, the vis cogitativa, and the memorative power are of better disposition, are better disposed to understand’ (Summa Theologiae, I q. 85 a 7). Often in Book II of the Summa Contra Gentiles, Aquinas writes about this relation of dependency of intellect on internal sensorium:

The soul [i.e. the intelligence] in order to understand, requires the powers, which prepare the phantasms so that they may be made actually intelligible [i.e. the vis cogitativa and the memory.] These faculties and their acts are found in certain organs of the body, and operate through these organs.

Given this, Aristotle wrote that ‘the soul does not understand without phantasms,’ and that ‘it understands nothing without the passive intellect’, which he also calls the vis cogitativa. (Summa Contra Gentiles, bk II, chs 80, 81)

The substantial form or the set of sortal properties is only potentially in the phantasm. The intellectus agens is a necessary condition for rendering the awareness of this substantial form from potency to act. The identity relation holds, nonetheless, but it is exemplified in two ways: potency and act. This is another case where the categories of potency and act are central to Aquinas’s mode of undertaking a rigorous philosophical analysis.

  • [1] Franz Brentano, ‘Nous Poietikos: Survey of Earlier Interpretations’, in Martha Nussbaum and AmelieRorty (eds), Essays on Aristotle’s De Anima (Oxford: Clarendon Press, 1992), 315.
  • [2] Kenny often refers to the intellectus possibilis as the ‘receptive intellect’.
  • [3] John Haldane, ‘Brentano’s Problem’ Grazer Philosophische Studien 35 (1989), 1-32 (emphasis added).
  • [4] Michon remarks that Thomas has three names that he uses in several texts: ‘the vis cogitativa, alsocalled ratio particularis and intellectus passivus’: ‘Intentionality and Proto-thoughts’, 337.
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