Aquinas’s Texts on Phantasm
In addition to the passages mentioned above, there are texts located in the Commentary on the Soul, the Summa Theologiae, and the Summa Contra Gentiles, where Aquinas argues that the phantasm is a ‘second movement’ whereas sensation is a ‘first movement’. Classifying a phantasm as a movement distinct from sensation entails an inconsistency if one claims that an awareness of phantasms is identical with or reducible to the acts of awareness from the external sensorium. The following passages indicate that phantasm awareness is necessarily distinct from, though dependent upon, the external sensorium: ‘The phantasm is not the first but a second perfection, for the imagination is a “movement” resulting from the exercise of a sense power’ (Summa Contra Gentiles, bk II, ch. 73, no. 11); ‘[there is . . .] an affinity between the phantasia and the senses in that the phantasia presupposes sensation and is found in sentient beings or animals’ (Commentary on the Soul, no. 657); ‘those animals have phantasia, in the precise sense of phantasia, which retain an imprint of things even while they are not sensing ‘exteriorly’ things’ (no. 390). ‘The outer senses in the act of sensing are always truthful; they cannot err about their proper object. But phantasms are very often deceptive, when there is nothing real that corresponds to them. Therefore, the phantasia is distinct from every sense in act’ (no. 645). And a final passage:
Aristotle distinguishes phantasia [. . .] first of all from sensation. [. . .] Regarding sensation, he begins by proving that the phantasia is not one of the senses [i.e. not one of the exterior senses], either potentially or actually. For phantasia is active during sleep. This cannot be due to any sense as in potency, in which state [i.e. in sleep] the senses are aware of nothing at all; nor to any sense as in act, for in sleep the senses are not in act. Thus, phantasms are neither an [external] sense in potency nor an [external] sense in act. (Commentary on the Soul, no. 641)
Other texts assert much the same regarding the non-identity of phantasm knowing and direct perception with the external sensorium: ‘Therefore, the phantasia is distinct from every sense in act’ (Commentary on the Soul, no. 645). ‘The phantasia is a movement resulting from an active exercise of a sense faculty’ (Summa Theologiae, I q. 84 a. 6 ad 2).
This textual evidence establishes that two propositions follow concerning the relation between the exercise of the external sensorium and the formation of phantasms:
- (a) Sensations of the external sensorium are necessary conditions for the intentional existence of any phantasm in the internal sensorium.
- (b) Sensations from the external sensorium are distinct structurally from the phantasms of the internal sensorium.
The passages above indicate that a phantasm, belonging to the internal sensorium, (i.e. the imagination, vis cogitativa, or sense memory) is a constituent of a mental process that follows from and depends upon sensation with the external sensorium. However a phantasm is neither equivalent to nor coextensive with the external sensorium. What is important textually and significant philosophically about the above passages is Aquinas’s claim that the phantasm is neither a sensation entity nor a sensation medium concurrent with a perceiver’s awareness of the external world by means of the external sensorium alone. A phantasm, therefore, is neither concomitant with nor coextensive with sensation. On the other hand, it results or is derived from the mental acts of sensation. The following passage further substantiates the claim that sensation awareness and phantasm-awareness are distinct and quite different species of awareness: ‘[P]hantasms... dwell within in the absence of sensible objects, as traces of actual sensations; therefore, just as sensations arouse appetitive impulses while the sensed objects are present, so do phantasms when these are absent’ (Commentary on the Soul no. 669; emphasis added).
In addition to passages indicating that the phantasm is not present in sensation, Aquinas, in discussing the formation of the species intelligiblis with the intellectus agens, considers the faculties that have phantasms. The phantasms serve as the object of the ‘scanning’ by the intellectus agens. No reference to either the sensus communis or to the external senses can be found: ‘By the vis cogitativa, together with the imagination and the sense memory, the phantasms are prepared to receive the action of the intellectus agens’ (Summa Contra Gentiles, bk II, ch. 60, no. 1). ‘The disposition of the vis cogitativa and the imagination are relative to the object, which is the phantasm. Because of the well-developed character of these powers, the phantasm is prepared in such a manner as to facilitate its being used to be made actually intelligible by the process of abstraction characteristic of the intellectus agens’ (bk. II, ch. 73, no. 28).
A phantasm, accordingly, is never involved with the direct act of sensation with the external sensorium alone. Insofar as a sense datum account of perception entails necessarily that a sense datum has a relation with the external senses, it follows that a phantasm cannot be reduced to a sense datum. Accordingly, a correct elucidation of
Aquinas’s theory of sensation and perception entails that a sense datum interpretation of a phantasm is both textually inconsistent and structurally inconsistent.