Review of: Johansen, T. K. (1998). Aristotle on the sense-organs. Cambridge.

Christopher D. Green
Department of
York University

Toronto, ON M3J 1P3

Ever since Putnam quipped "what we [computational functionalists] are really interested in, as Aristotle saw, is form and not matter" (1975, p. 302), the question of whether Aristotle's theory of mind can be considered to have been functionalist has been a relatively "hot" one in classical philosophy circles.  Many contemporary luminaries of philosophy have entered into the debate with all their passion and intelligence. After simmering for over a decade, the matter came to head with the publication of Nussbaum and Rorty's Essays on Aristotle's De Anima (1992), which contained position papers from most of the major players: Nussbaum and Putnam, Burnyeat, Sorabji, Lloyd, Marc Cohen, and others.

T. K. Johansen's recent book, Aristotle on the sense-organs (1998), emerges from this debate, and is a most original and enlightening contribution.  It is a revision of his 1994 Cambridge Ph.D. thesis, written under the supervision of one of the controversy's principals, Myles Burnyeat, and is one of the most detailed and thoughtful accounts of the matter ever written.  It begins with a brief description of the modern functionalist debate, but quickly moves on to a minute examination of Aristotle's own accounts of each sense organ.  The first substantive chapter, on the sense of sight, runs over 90 pages length, analyzing not only the Stagirite's theory of this most important of sense modalities, but also setting Aristotle's position in historical context -- his disputes with advocates of Empedocles' and Democritus' "materialist" theories -- thereby clarifying much that is otherwise obscure to the present-day reader. 

One of the most obscure aspects of Aristotle's theory is his insistence that all sensation must employ a medium between the sense-object and sense-organ.  In the case of vision, for instance, the medium was said to be air or water, but not as such; air and water serve as media of vision only because they are (or more correctly, can be made to be, by fire) transparent, and so "the transparent" was Aristotle's medium of sight.  Johansen is sensitive to his reader's likely perplexity here, and so follows his chapter on sight with one specifically on the concept of the medium itself.  His key argument is that the medium is not to be viewed as a material substance that transmits material processes, the way that, say, a stick can be used by a hand to push a ball.  The change caused by the sense-object in the sense-organ was thought to happen through the medium, Johansen tells us, not in it.  Thus, a red object may cause redness in my eye, in some sense, but it does not cause the air itself to go red. 

This discussion sets up his account of the other senses in the following chapters.  In each case the focus is on the material of the sense-organ and of the medium, and on the properties these have, and in virtue of which they are able to carry out their assigned sensory functions.  In his conclusion, Johansen argues that Aristotle was not a functionalist because, although he allowed for a narrow range of material realizations of sense-organs from one species of animal to another, their being made of the one or two substances with the required properties was critical to Aristotle.  I am not completely convinced by Johansen that functionalism must be as liberal with matter as he claims to be worthy of its name, but the strength of this book is that it is so exacting and nuanced in its handling of the material that broad terms like "functionalism" become too crude to carry the weight of the debate, and we are repeatedly driven back to the text and to what Aristotle actually said.


Johansen, T. K. (1998). Aristotle on the sense organs. Cambridge, UK: Cambridge University Press.

Nussbaum, M. C. & Rorty, A. O. (Eds.) (1992).  Essays on Aristotle's De anima. New York: Oxford University Press.

Putnam, H. (1975). Philosophy and our mental life. In Mind, language, and reality: Philosophical Papers, Vol. 2. pp. 291-303. Cambridge, UK: Cambridge University Press.