This paper aims to identify several interpretive problems posed by the final part ofDAII.11 (423b27–424 a10), where Aristotle intertwines the thesis that a sense is like a ‘mean’ and an explanation for the existence of a ‘blind spot’ related to the sense of touch, adding the further contention that we are capable of discriminating because the mean ‘becomes the other opposite’ in relation to the perceptible property being perceived. To solve those problems, the paper explores a novel interpretation of Aristotle’s (...) claims, arguing that they describe a homeostatic physiological reaction by which the sensory apparatus responds to perceptible stimuli. According to the proposed interpretation, such homeostatic reaction constitutes a necessary condition for perceiving what Aristotle refers to as ‘proper’ perceptible features, which include properties like ‘hot’ and ‘cold’ as well as colors and sounds. (shrink)