The Vis Cogitativa. On Perceiving the Individual
When considering the objects of sensation in the preceding chapters, brief mention was made of the incidental object of sense. This object of perception, discussed only sketchily by Aristotle, is the direct object of awareness of the internal sense faculty that Aquinas calls the vis cogitativa. The exact nature of this faculty requires an explication of the internal sensorium. Having completed that task in the preceding chapters, it is now time to venture into the uncharted waters of analysis of this unique faculty of inner sense in Aquinas’s philosophy of mind.
Writing on contemporary naturalist epistemology, Haldane argued persuasively, it will be recalled, that discussion was needed in this area of inner sense in Aquinas along with the intellectus agens: ‘What is now needed, however, is a fully perspicuous philosophical account [ . . . ] of the nature and operations of what in the Aristotelian- Thomistic tradition are spoken of as the “cogitative powers” and the “active intellect”. That might be one of our tasks for the next century’1 The task about to be undertaken will push forward an analysis of the ‘cogitative powers’ that Haldane considers necessary. Secondly, suggestions will be offered concerning how the vis cogitativa may assist in determining a contemporary account of the intellectus agens. In this study, however, the particular set of issues addressed concern principally Aquinas’s account of sensation and perception. Attention to concept formation through the intellectus agens is given only peripherally. One of the principal goals is to elucidate how Aquinas handles the issue of perceiving an individual as an individual and not merely as a collection of sensible qualities.1   Hence, Aquinas provides a proposal offering a solution to Ryle’s puzzle.
Inner sense has proven to be a terribly difficult bit of Aquinas’s philosophy of mind to render into a consistent exposition. Klubertanz’s extensive philosophical narrative,
The Discursive Power, is one of the more detailed analyses of the vis cogitativa in Aquinas.4 Kemp’s several essays treat the vis cogitativa as discussed in both Arabian and western European theories of mind.5 An article published in The Modern Schoolman probably best describes lack of scholarship on inner sense in Thomas: ‘A Forgotten Sense: The Cogitative According to St. Thomas Aquinas’6 In his account of Aquinas’s philosophy of mind from the perspective of scholastic Thomism, Peifer does not discuss the role of the vis cogitativa.7 Martin shrugs his shoulders, it appears, by remarking: ‘it is impossible here to enter into a discussion of Aquinas’s views on [the vis cogitativa].’8 Stump does not consider the vis cogitativa, although she spends considerable time offering an analysis of phantasms.9 In his essay on Aquinas’s philosophy of mind, Kretzmann does not discuss the vis cogitativa.10 In his Medieval Philosophy, Kenny, in discussing the vis aestimativa and the vis cogitativa, provides the usual examples of instinct for the mental acts of the vis aestimativa; yet he is perplexed by the vis cogitativa.11 Kenny, in an earlier text, attributes to the concept of inner sense a Cartesian mental awareness devoid of sense awareness; he comments less than positively about the nature of inner sense, which he takes to misrepresent the imagination, among other acts of awareness: ‘Hence, if the whole notion of inner sense is misconceived, then not only the objects of imagination are misrepresented as inner sense data, but so also, more importantly, there is a misunderstanding underlying the idea that there is an inner subject of sensation, the self of empiricist tradition.’12
Kenny is concerned, it appears, about a mental act of awareness of inner sense that is unconnected with any direction to the outside world. This would be the Cartesian— and probably the Lockean—concept of inner sense. Aquinas, however, focuses attention on the faculties of inner sense, which are rooted in the internal sensorium that provide an explanatory account of the pre-analytic data of some of acts of human awareness.13 This chapter, accordingly, embarks on an analysis of Aquinas’s
theory on the vis cogitativa with the intention of assisting discussions of Aquinas’s realist account of sensation and perception. It goes beyond the limits of inner sense that bother Kenny, responds to Kenny’s worries about Aquinas’s unclarity on this inner sense faculty, and resolves what Frede called ‘an embarrassment’. The analysis put forward will enhance Aquinas’s claims for both an ontological realism and an epistemological realism.
The Vis Aestimativa and the Vis Cogitativa
Aquinas distinguishes the vis aestimativa from the vis cogitativa because the former, he suggests, pertains to animal perceivers and the latter to human perceivers. Both sense faculties are posited to account for an object of sensation that goes beyond the ‘concrete wholes’ synthesized and conjoined by the sensus communis from the discrete sensibles of the external senses. Aquinas offers the following data establishing an epistemological foundation for positing this unique internal sense faculty: ‘Furthermore, for the apprehension of intentions that are not received through the senses, the aestima- tive power is appointed; and for their preservation, the memorative power, which is a storehouse (thesaurus) for such intentions’ (Summa Theologiae, I q. 78 a. 4; emphasis added). In De Veritate, Aquinas writes that ‘the imagination, which is the storehouse of forms received by the senses, [ . . . and . . . ] the memory, for particular apprehensions not received from the senses’ (De Veritate II, q. 10).
Aquinas suggests that the act of awareness of this inner sense faculty goes beyond the data of sensation as determined by the external sensorium. ‘Animals, therefore, need to perceive such intentions, which the exterior sense does not perceive. Now some distinct principle is necessary for this, since the perception of sensible forms comes by an immutation caused by the sensible, which is not the case with the perception of the above intentions’ (Summa Theologiae, I q. 78 a. 4; emphasis added). This set of passages describes the function of the vis aestimativa, which functions so that a sensing animal is aware of ‘intentions’ that are not perceived or perceivable directly in the external world. This is what several late medieval philosophers called an ‘intentio non sensata’; Aquinas refers to this term as ‘sensibile per accidens’. With the vis aestimativa, this faculty functions something like what a contemporary zoologist would call some form of ‘instinct’. The wolf, which makes the sheep run, is perceived through the external sen- sorium of the sheep only as a dark object of a certain shape making certain sounds in the near distance. The sheep, so Aquinas suggests, is aware directly of this dark, moving, sound-producing object of a particular shape as a ‘thing to be feared’. The fact that the sheep is aware of something beyond what is sensed immediately, according to Aquinas, indicates that there is a need for postulating a sense faculty that is able structurally to account for this kind of awareness. The same evidence accounts for the bird’s gathering certain straws in order to build a nest.
From Aquinas’s writings, there appear to be three kinds or levels of sense knowledge appropriate to different levels of animal life. It follows that ‘instinct’ is too broad and inclusive a concept under which to place all forms of animal sense knowledge. In Book I of the Commentary on the Metaphysics, Thomas discusses these three areas of sensitive awareness proper to non-human animals. It appears that by means of the differentiation of sense powers, Aristotle and Aquinas are determining different levels of sense life in what the medievals often referred to as brute animals. The following passages illustrate Aquinas’s keen powers of observations regarding various forms of animal life:
It is evident, then, that there are three levels of knowing in animals. The first level is that had by animals which have neither hearing nor memory, and which are therefore neither capable of being taught nor of being prudent. The second level is that of animals that have memory but are unable to hear, and which are therefore prudent but incapable of being taught. The third level is that of animals which have both of these faculties, and which are therefore prudent and capable of being taught. Moreover, there cannot be a fourth level, so that there would be an animal that had hearing but lacked memory. For those senses which perceive their sensible objects by means of an external medium—and hearing is one of these—are found only in animals which have locomotion and which cannot do without memory. [Aquinas remarks that this last point was noted in Section 10.] (Commentary on the Metaphysics, bk I, sec. 13)
What is interesting in this passage is that the third level of animal sensitive life appears to border that life modelled by human persons. Aquinas uses the term ‘prudence’ in these discussions. Yet it is different from ascribing the same term to a human person. Aquinas continues:
Again, from the fact that some animals have memory and some do not, it follows that some are prudent and some not. Since prudence makes provision for the future from memory of the past (and this is the reason why Tully in his Rhetoric, Book II, makes memory, understanding and foresight parts of prudence), prudence cannot be had by those animals that lack memory. Now those animals that have memory can have some prudence, although prudence has one meaning in the case of brute animals and another in the case of human persons. Human beings are prudent inasmuch as they deliberate rationally about what they ought to do. Hence it is said in Book VI of the Ethics, that prudence is a rationally regulated plan of things to be done. But the judgement about things to be done which is not a result of any rational deliberation but of some natural instinct is called prudence in other animals. Hence in other animals, prudence is a natural estimate about the pursuit of what is fitting and the avoidance of what is harmful; for example, as a lamb follows its mother and runs away from a wolf. (Commentary on the Metaphysics, bk I, sec. 11)
More than a few passages suggest that Aquinas sought the use of ‘instinct’ as an umbrella concept under which would fall several sensitive awarenesses found in animals. In the case of instinct, furthermore, Aquinas appears to accept some rendition of an ‘innate idea’ position, from which follows an epistemological structure of nativism. The animal manifests behaviour that exceeds the limits of that which is sensed directly. Accordingly, Aquinas modifies somewhat his axiom: ‘Nihil est in intellectu quod non prius fuerit in sensu. Here instinct seems to be functioning as an innate cognitive structure. The concept of an intentio non sensata is apparent. This innateness functions as a ‘conditioning’ of the mental act so that the act perceives the object in a unique way; it appears that Aquinas suggests a form of nativism for the vis aestimativa. An important corollary concerns whether the vis cogitativa requires an innate idea in order to function; this will be addressed later. Nonetheless, the reference to the vis aestimativa in the Summa Theologiae is one of the rare texts where Aquinas considers innate ideas.
That Aquinas considers the vis aestimativa as instinct is clear from the following passage: ‘But the lower animal’s awareness of individualized notions is called natural instinct, which comes into play when a sheep, for example, recognizes its offspring by sight, or sound, or something of that sort’ (Commentary on the Soul, no. 397). The Latin text is ‘in animali vero irrationali, fit apprehensio intentionis individuals per aesti- mativam naturalem (bk II, lectio xiii). The terms ‘aestimativam naturalem are translated as ‘natural instinct’. However, in the Summa Theologiae, Aquinas writes that ‘nam alia animalia percipiunt huismodi intentiones solum naturali quodam instinctu (Summa Theologiae, I q. 78 a. 4). Here Aquinas uses the Latin term ‘instinctu. In De Veritate, he writes about the vis aestimativa: ‘Sed vis aestimativa, per quam animal apprehendit intentiones non acceptas per sensu, ut amicitiam vel inimicitiam [ . . . ]’. The translation of this passage is as follows:
Thus the imaginative power belongs to the sensitive soul in accordance with its own nature, because forms received from sense are stored up in it; but the estimative power, by which an animal apprehends intentions not received by the senses, such as friendship or hostility, is in the sensitive soul according as it shares somewhat in reason. It is accordingly in virtue of this estimative power that animals are said to have a sort of prudence, as is seen in the beginning of the Metaphysics. A sheep, for example, flees from a wolf whose hostility it has never sensed. (De Veritate, q. 25 a. 2)
In this text, Aquinas suggests that the higher animals have a sense of perceiving the external world that differs in kind from the lower animals. There are, to reiterate, three levels of sense knowledge in non-rational animals. Here Aquinas notes that a dog, for instance, immediately perceives a person as friendly or not friendly.
The metaphilosophy Aquinas utilizes in discussing the vis aestimativa is consistent with his holistic treatment of sensation and perception. He seeks to develop a conceptual possibility for explanation. The effect of this suggestion is that he assumes as a given datum of sense experience—a pre-analytic datum of awareness—that per- ceivers undertake acts of awareness about the external world in a certain manner. He next attempts to provide an explanatory account for these mental acts in terms of a faculty psychology.  Strawson and Aquinas take as a given that human knowers perceive certain facets of the world around them. Next a philosophical attempt is undertaken, using what Strawson referred to as ‘descriptive metaphysics’ rather than ‘revisionary metaphysics’, to set out how this procedure explains the possibility for perceptual experience to occur. The weight of these remarks must be taken in context. It is certainly a mistake as well as irrelevant to make Aquinas into a Strawsonian or whomever. Nonetheless, while Whiggish history of philosophy is useful only up to a point, there are important similarities in their modus operandi approaching issues in intentionality. These metaphilosophical similarities are, moreover, illustrative similarities.
In Avicenna’s texts, human persons also have a vis aestimativa, which is one internal sense faculty where Aquinas calls for two: the vis aestimativa and the vis cog- itativa.21 Klubertanz notes that Averroes claimed that human persons have what he called a ‘virtus cogitativa’; moreover, Averroes interpreted the function of the vis cogi- tativa as being so important that he referred to this inner sense faculty at times as ‘intellect’ or ‘reason’. Aquinas articulated his criticism of Averroes’s position on the separated nature of the intellect. Aquinas refines his own position on the role of the internal sensorium and its relation to the intellectus agens and the intellectus possibi- lis. The faculties of the internal sensorium, like the faculties of the external senso- rium, are always connected ontologically with a physiological organ, which is the vehicle. Averroes, in particular, writes often about the physiological locus of the internal sense faculties.