Against Functional Reductionism in Cognitive Science

Abstract

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.

Acknowledgements

I am grateful to two anonymous referees for this journal for very constructive criticism that led to major changes to this paper. I would like to thank the University Research Board of the American University of Beirut for two summer grants that enabled me to write this paper.

Notes

[1] Of course, properties do not cause other properties: it is property instances as manifested in events that are causally efficacious. In what follows, I will be speaking loosely.

[2] Those properties may themselves be predicates reducible to lower‐order properties; I will ignore this complication in the rest of the paper. Also, in what follows, I will sometimes refer loosely to these predicates as ‘properties’, as Kim himself does on occasion.

[3] Lewis’s functional reduction of psychological predicates builds on his earlier proposal for defining theoretical terms, as outlined in Lewis (1970/1983). He draws on Ramsey’s method for expressing scientific theories, but in a twist on the theoretical–observational distinction, he postulates that the theory being interpreted contains two sets of terms, T‐terms and O‐terms, characterized as follows. A T‐term is ‘a theoretical term introduced by a given theory T at a given stage in the history of science’, and an O‐term is, by elimination, ‘any other term, one of our original terms, an old term we already understood before the new theory T with its new T‐terms was proposed’ (Lewis 1970/1983, 79). Accordingly, in the above presentation, the T‐terms are none other than X, Y, and Z. As applied to a psychological theory, the identification of O‐terms with ‘old’ terms and T‐terms with newly introduced terms is not entirely apt. The terms distinctive to psychological theorizing are often familiar mentalistic terms that have been in use for some time (‘belief’, ‘desire’, ‘fear’, ‘pain’, etc.), while the O‐terms can be thought of as terms denoting various environmental stimuli and behaviors.

[4] In what follows, I will sometimes talk about the category or concept of fear (in italics), but I will also speak of a state or property of fear (no italics). In adopting the latter terminology, I do not mean to be prejudging the case for or against reduction; any mention of a property or state of fear can be paraphrased in terms of a category or concept of fear (which is denoted by the predicate ‘fear’).

[5] It should be noted that these behaviors, while typical and manifested by numerous individuals, were not universally exhibited in the three conditions; e.g. some monkeys froze in ST (see Buss et al. 2004, 585).

[6] See Dupré (1993) and LaPorte (2004), from which some of these examples are taken (though LaPorte would not agree with the position I am defending here). See also Khalidi (1993, 1998).

[7] This argument against functional reductionism is therefore what Ruphy (2005) considers a ‘temporally qualified argument’ against reductionism, since it depends on our explanatory and classificatory practices.

[8] Horgan argues that philosophically important concepts like causation need to accord not just with our intuitive judgments, but also with untendentious scientific knowledge, sociolinguistic purposes, and other types of data, all of which ‘go into the hopper of wide reflective equilibrium’ when determining the proper analysis of such concepts (Horgan 2001, 109).