You are here

Aristotle and the Physiology of Sense Organs

John Thorp

Much thought has been given, and many pages have been devoted, to the debate between "literalist" and "spiritualist" interpretations of Aristotle on sense perception.[1] The literalists, broadly, hold that in perception the organ quite literally takes on the perceived quality – eyes become red and tongues become salty – and that that is all that needs to be said. The spiritualists hold, by contrast, that sense perception requires that the organs take on the character of the perceived object in a special way, variously called "intentional" or "spiritual".[2]

For this paper today I want simply to bracket that debate, which I see as a debate about the metaphysics of perception, for it steers us quickly into the awful chasm of the mind-body problem. I want to restrict myself to a much narrower and humbler focus, a purely physiological one. I want to raise the question how Aristotle thought that sense organs functioned, simply at the physiological level. If I might draw an inevitably artificial boundary, I would say that this paper is an excursus into the history of science, rather than into the history of philosophy.

I will, first, be defending physiological literalism, the idea that, whatever else may or may not need to be said, it is at least the case that Aristotle takes it that sense organs actually take on the character of the perceived object, in a perfectly natural, straightforward sense. I will remain agnostic about whether he thinks that they also take on something else, harder to describe: a "spiritual" or "intentional" form. What I argue here is not in itself inimical to either of the traditional warring camps.[3]

Second, after I have defended literalism, I will argue that Aristotle also has something else in mind, something of a purely physiological sort: he sees sense organs as physiological homeostats.

[1] The debate began with Sorabji's "Body and Soul in Aristotle" Philosophy 49 (1974) 63-89,  passingly stating the literalist position. Burnyeat responded, most famously, in "How Much Happens when Aristotle Sees Red and Hears Middle C?, Remarks on De Anima ii 7-8" found in Nussbaum & Rorty, eds, Essays on Aristotle's de Anima(1995) Oxford (421-434). The debate has been carefully and thoroughly summarized by Caston, "The Spirit and the Letter", in R. Salles (ed) Metaphysics, Soul and Ethics in Ancient Thought: Themes from the Work of Richard Sorabji, (2005), Oxford, Clarendon Press.

[2] I suppose the chief classical proponent of this view is Aquinas, who writes: … alterius modi esse habet forma in sensu, et in re sensibili.  Nam in re sensibili habet esse naturale, in sensu autem habet esse intentionale et spirituale.Commentary on the de Anima, ad B 12, ¶552. The view, however, is much older, going back at least to Themistius, who writes: The sense organs do not become the matter of perceived qualities; for the organ does not turn white or black.... rather the organ receives the form and the logosCommentaria in Aristotelis de Anima, ad B 12 (CAG Vol 3, p.78)

[3] It is something of a puzzle to me that spiritualists generally seem, in their statements of the position, to say that the organ doesn't take on the form of the object literally, or naturally, but rather…. I don't see why the spiritualist position needs to deny physiological literalism; what is presumably important for them is that the spiritual or intentional item is present; it is not required for that that the natural or literal item be absent.

Session/Panel Title


Session/Paper Number


© 2020, Society for Classical Studies Privacy Policy