Direct Realism Redux
The claim that Aquinas is a direct realist is central to the twin claims about his ontological realism and his epistemological realism conjoined with his externalism. If the 
phantasm becomes a direct object of knowledge with the external sensorium, then Aquinas is a representationalist and not an externalist. Passages from several texts note that Aquinas claims that the ‘thing’ or ‘quality’ in the physical world is the object of knowledge and not the ‘idea’ of the thing or quality: ‘The sense objects, which actuate the sense faculties—the visible, the audible, etc.—exist outside the perceiver. Thus, actual perception attains to the things, which exist in the external world’ (Commentary on the Soul, no. 375; emphasis added); ‘Sense faculties are passive. They are immuted by the sensible objects existing in the external world. Thus, the exterior cause of the immutation in the sense faculty is per se that which is perceived by the sense faculties’ (Summa Theologiae, I q. 78 a. 3).
One passage from the Summa Theologiae offers textual evidence that Aquinas denied explicitly that the sensation or idea itself is the direct object of knowledge. This entails a fortiori a denial of representationalist theory, and indicates the externalism and the corresponding epistemological realism central to Aquinas’s philosophy of mind.
The relevance of Aquinas’s obj ections lies in the explicit claim that a mental state itself as a tertium quid is not the direct object of knowledge. He affirms some common-sense observations about the epistemological ramifications of representationalism; he suggests that if mental states themselves are the direct objects of knowledge, then two odd philosophical conclusions follow:
- (a) A perceiver could never know anything beyond her mental states, and thus every inquiry would be nothing more than a psychological inquiry into inner sense.
- (b) If sensations themselves and not the objects in the world were the direct referent of mental acts, then Protagoras’s relativist dictum ‘Man is the measure of all things’ would become the established epistemological norm.
By indicating in a dialectical manner what philosophically odd conclusions follow necessarily from any representationalist theory (i.e. one that has as the direct object of a mental act the very mental entity itself), Aquinas provides a reductio ad absurdum argument against representationalism. What concerns him is that if one does not get beyond the mental state, then one is never aware of the external world. That this is the heart of the realism/idealism and the externalist/internalist issues is obvious. In effect, Aquinas states precisely where certain philosophical problems lie with representative realism; i.e. how to connect the representation with that which is represented. He suggests that representative realism is a priori untenable. This entails the acceptance of some form of epistemological realism. In his Medieval Philosophy, Kenny argues for the direct realism and externalism in Aquinas.
‘Phantasm’ is an often-used term in the writings of Aristotle and Aquinas. Yet the ‘logic’ of the analysis of this concept is difficult to unpack consistently. In her Aquinas, Stump writes about the difficulty of sorting out exactly what Aquinas may have meant by the concept of ‘phantasm’: ‘But Aquinas’s views about phantasms are a perplexing part of his account of cognition, since, at first glance, phantasms seem entirely superfluous as regards the cognition of extra mental reality.’ In this context, Stump appears concerned about how Aquinas uses phantasms when he considers the abstraction by means of the intellectus agens of an intelligible species from the phantasms as well as the exercise of the concepts by the intellectus possibilis once abstraction has occurred. In his Aquinas on Mind, Kenny notes: ‘how much else is covered by the word [phantasm] is difficult to determine.’ In his ‘Intentionality: Aquinas and Wittgenstein’, Kenny reminds us of the difficulties encountered in providing a consistent analysis of the ‘logic’ of the concept of phantasm in the texts of Aquinas:
It is not altogether clear what Aquinas means by phantasmata: I have been translating his references to them by vague and benign phrases such as ‘reference to a content of sense and imagination’. I believe that in Aquinas’s dicta about phantasms there is combined a correct and important insight about the relation between the intellect on the one hand and the imagination on the other, with a confused theory about the nature of the imagination and the character of mental imagery.
In discussing the nature and structure of phantasms, there are at least three possible alternative accounts. Each of these accounts can be interpreted as an explicatio textus providing a conceptual analysis of a phantasm. Two of these positions have been argued for explicitly or are at least implied by various philosophers who have provided an analysis of Aquinas’s theory of perception. In the next chapter, a third position will be offered reconstructing the ‘logic’ of the use of ‘phantasm’; this entails that the other two accounts interpreting phantasms are untenable structurally and inconsistent textually. The positions argued against are stated generally as follows: (a) a phantasm is structurally identical to a ‘sense datum, and (b) a phantasm is always to be identified with a ‘sense image’.
Although both these positions are fundamentally mistaken, nonetheless some texts found in the writings of Aquinas suggest each of them. The problem, therefore, is to provide a structural elucidation consistent with the whole of his theory of knowledge and philosophy of mind. This present inquiry can be regarded as a conceptual analysis, first of all, attempting to disprove both of the above positions, and secondly, elucidating a consistent account of the nature of a phantasm. Needless to say, a definitive account of the logic of the concept of a phantasm is difficult. Aquinas is limited in what he writes constructively about this intentional entity. Contemporary readers almost have the impression that Aquinas was certain that the nature of a phantasm was a pervasive term in thirteenth-century philosophy and common parlance in epistemological discussions; hence, there was no need to offer a further explication of this concept.  The lack of elucidation on Aquinas’s part forces the contemporary philosopher into reconstructing an explanatory account. This conceptual analysis, insofar as it is a reconstruction, must be reconcilable with the other texts of Aquinas that treat issues in the philosophy of mind. One sees the range of texts Aquinas employs when using phantasms.
-  Geach in Mental Acts suggests that this ‘conversio' relation is a difficult bit of philosophy to elucidateconceptually. Geach refers to the conversio ad phantasmata phrase as being metaphor though certainly important metaphor.
-  Summa Theologiae, I q. 85 a. 2; this text appears in Ch. 7.
-  Aquinas’s method here reminds one of Austin’s trenchant remarks directed against the ‘quirkiness’ ofsense data theories.
-  Putnam expressed these same concerns when he criticized what he called the ‘inner theatre of themind’ position exemplified in most representationalism. Ryle too expressed these worries.
-  Texts from Kerr’s After Aquinas: Versions of Thomism suggest the radical incompatibility of Thomas’sposition with early modern representationalism. On the charge of question-begging in such matters, seeRoderick Chisholm, The Problem of the Criterion (Milwaukee, Wis.: Marquette University Press, 1973).
-  ‘Some philosophers believe that in sense-experience we do not directly observe objects or propertiesin the external world, but rather perceive private sense-data from which we infer the nature of externalobjects and properties. In Aquinas, there are no such intermediaries between perceiver and perceived. Insensation the faculty does not come into contact with a likeness of the object; it becomes itself like theobject by taking on its form. This is summed up in the slogan taken from Aristotle: the sense-faculty inoperation is identical with the sense-object in action (sensu in actu est sensible in actu): Anthony Kenny,Medieval Philosophy (Oxford: Clarendon Press, 2005), 234.
-  Eleonore Stump, Aquinas (London: Routledge, 2003), 256.
-  Anthony Kenny, Aquinas on Mind (New York: Routledge, 1993), 93.
-  Anthony Kenny, ‘Intentionality: Aquinas and Wittgenstein, in The Legacy of Wittgenstein (Oxford:Oxford University Press, 1984), 71; repr. in Brian Davies, OP (ed.), Thomas Aquinas: ContemporaryPhilosophical Perspectives (Oxford: Oxford University Press, 2002), 243-56.
-  One possible area for further research on phantasms might be discovered in the medieval Arabianphilosophers; Aquinas often refers to Avicenna and Averroes.
-  Anthony Kenny, ‘Intellect and Imagination in Aquinas’, in Kenny (ed.), Aquinas: A Collection ofCritical Essays (Garden City, NY: Doubleday Anchor, 1969), 273-93. Nonetheless, in these earlier critiquesof phantasms, Kenny vacillated between an image and a sense datum position.