The Coloration of Aristotelian Eye-Jelly: A Note on On Dreams 459b-460a

The purpose of this paper is to make a small contribution to a recent lively debate concerning Aristotle’s philosophy of mind. This debate has centered on a paper published by Myles Burnyeat,¹ which argued that Aristotle’s philosophy of mind, being hopelessly anachronistic, could not serve as the prototype of any contemporary theory: in particular, it could not be seen as proto-functionalist, as Nussbaum and Putnam had proposed.² The grounds given by Burnyeat for the anachronism of Aristotle’s philosophy of mind focus mainly on Aristotle’s notion of perceptual awareness. According to Burnyeat, perceptual awareness is for Aristotle a primitives³ and essential⁴ property of the relevant organ of perception. In Burnyeat’s view, Aristotle’s theory denies that there is any further level of analysis that can be undertaken. When an eye comes to perceive an object, the potentiality of the eye for seeing is actualized, but there is nothing further to be said. In particular, there is no physiological change taking place in the eye, in which the psychological change is realized. Thus, when Aristotle says in the De Anima that the eye becomes “in a way coloured”⁵ when it sees a coloured object, for Burnyeat this means no more than that it registers awareness of colour,⁶ not that it becomes literally coloured itself.

On this last point, Burnyeat takes issue with the view of Richard Sorabji,⁷ who maintains that for Aristotle the eye does undergo physiological change when it does some seeing: in particular, if it sees, for example, a red object, then the jelly inside the eye literally becomes coloured red. On this view, Aristotle does indeed have a theory, congenial enough to modern perspectives, whereby each psychological change is realized physiologically.⁸

There are several large questions which my paper does not attempt to address. Firstly, it offers no view on what implications Burnyeat’s position would have, if correct, for the interpretation of Aristotle as a proto-functionalist. Secondly, it does not offer a view on how necessary the correctness of an interpretation such as Sorabji’s is to the case made by the advocates of Aristotle as a proto-functionalist.⁹ Thirdly, it makes no adjudication between any of the competing parties’ interpretations of Aristotle’s De Anima, his main work on psychology and the chief textual battleground in the debate I have been outlining.

This paper’s aim is a much more modest one. It is to draw attention to a short passage in Aristotle’s work On Dreams, which in my view incontrovertibly suggests that Aristotle did believe that the eye becomes literally coloured during perception of a coloured object. I shall therefore be presenting one piece of evidence in favour of Sorabji’s view; but I shall not be arguing that Sorabji’s view is conclusively the right one (which would require consideration of all the relevant evidence), nor drawing any conclusions about the implications of this evidence for interpretations of Aristotle’s philosophy of mind. It is, however, reasonable to suggest that if Sorabji’s view is right then Burnyeat’s view is in severe difficulties, since its main underpinning—the claim that psychological change has no physiological counterpart in Aristotle’s theory—will have been removed. The evidence I have to present, then, is, albeit indirectly, support for the view that Aristotle’s philosophy of mind is not hopelessly anachronistic, at least in the way that Burnyeat claims.

Here is the evidence from On Dreams (459b23–460a26):

That the sense-organs rapidly perceive even slight differences is shown by what happens with mirrors. Indeed, anyone who would give his attention to it might look into that subject too and explore the problem. At the same time, it is clear from this case that, just as the organ of sight is affected by, so too it acts upon, its object. For in extremely clean mirrors, when women look into them during their menstrual period, the mirror surface takes on a sort of blood-red cloud. In fact, if the...