Against Functional Reductionism in Cognitive Science

Functional reductionism concerning mental properties has recently been advocated by Jaegwon Kim in order to solve the problem of the ‘causal exclusion' of the mental. Adopting a reductionist strategy first proposed by David Lewis, he regards psychological properties as being ‘higher-order' properties functionally defined over ‘lower-order' properties, which are causally efficacious. Though functional reductionism is compatible with the multiple realizability of psychological properties, it is blocked if psychological properties are subdivided or crosscut by neurophysiological properties. I argue that there is recent evidence from cognitive neuroscience that shows that this is the case for the psychological property of fear. Though this may suggest that some psychological properties should be revised in order to conform to those of neurophysiology, the history of science demonstrates that this is not always the outcome, particularly with properties that play an important role in our folk theories and are central to human concerns.