A fifth argument is alleged from Aristotle, De anima, III, iv, 6, which comes to this: -- A sensory organ is damaged by meeting with its object in a high degree: vivid light is seen, and crashing sounds are heard, but to the damage of eye and ear; whereas a highly intellectual object, -- Aristotelian psychology, for example, -- if understood at all, is understood to the improvement of the understanding; the understanding, as such, not working through any bodily organ.
St Thomas however is far from confining dumb animals to mere sensation. He allows them sense memory, phantasy, a sort of judgement called vis aestimativa (notes pp. 122, 125), and a certain power of self-determination (Chap. XLVIII, n. 2). He denies in the intellect, free will, the powers of forming general concepts and determining their own judgements, and the immortality of their souls.
Of God and His Creatures: 2.66