This interpretation of inner sense saves the ontological realism on which Aquinas builds his philosophical system. To save this realism is not an arcane or idle philosophical question. Writing in NewBlackfriars, Pickstock, adopting a postmodernist position of internalism and anti-realism, asks the following question, and many contemporary philosophers think not rhetorically: ‘How should one respond to the death of realism, the death of the idea that thoughts in our minds can represent to us the way things actually are in the world? For such a death seems to be widely proclaimed by contemporary philosophers.’
A response to an internalist position like that articulated by Pickstock and defended by MacDonald would go something like this. Aquinas, like Gibson, assumes that there is a world around us. He asks, as Gibson does, what must be necessary in order for us to know and understand this world of individuals. Gibson would appeal to evolutionary development in order to explain how our perceptual apparatus developed. Nonetheless, Gibson and Aquinas adopt the same metaphilosophical approach: how do philosophers explain the common-sense awareness of the world around us? The vis cogitativa assists Aquinas in maintaining this philosophical realism in opposition to the postmodernist argument of Pickstock. This account renders more persuasive the structural connection between the vis cogita- tiva and its phantasms, the sense memory and its phantasms, and the power of abstraction with the intellectus agens. If the sense memory stores the acts of awareness of the vis cogitativa, then this provides a more perspicuous array of phantasms on which the intellectus agens might act in ‘abstracting’ the species intelligiblis, which permits the intellectus possibilis to know the sortal properties that determine a natural kind. Moreover, this interpretation renders more understandable the famous ‘army in retreat’ metaphor that Aristotle uses in Book II of the Posterior Analytics and on which Aquinas comments.
In opposition to Moore’s ‘diaphanous arrow of consciousness, Aristotle and Aquinas adopt a ‘structured mental act’. There are two important intentional structures embedded in cognitive faculties in Aquinas’s philosophy of mind:
- (a) the intellectus agens;
- (b) the vis cogitativa.
Both these intentional structures are necessary conditions in order for Aquinas to provide an explanatory account of an awareness of essential properties. Both get beyond the direct data from the external senses. In discussing Gilson on Aquinas’s philosophy of mind, Peterson wrote that ‘the senses carry a message which they cannot themselves interpret’. Peterson and Gilson refer here only to the intellectus agens. This chapter argues unequivocally that the vis cogitativa must be included in this discussion.
-  For a complete analysis of Aquinas’s metaphysical thesis of ontological realism, see John F. Wippel,The Metaphysical Thought of Thomas Aquinas: From Finite Being to Uncreated Being (Washington, DC:Catholic University of America Press, 2000).
-  Catherine Pickstock, ‘Imitating God: The Truth of Things According to Thomas Aquinas, New Blackfriars 81(953/954) (2000), 308.
-  While this analysis suggests a cognitive structuralism on inner sense, this does not entail that theanalysis Aquinas provides on the vis cogitativa is either connected with or dependent upon what has beencalled ‘Transcendental Thomism’.
-  See John Peterson, Realism and Logical Atomism (Tuscaloosa: University of Alabama Press, 1976), 7.