From Epiphenomenalism to Eliminativism?1

Chapter 13 From Epiphenomenalism to Eliminativism?1

Krzysztof Posłajko

Abstract

Jaegwon Kim used the causal exclusion argument as a weapon against non-reductive physicalism in the philosophy of mind. The aim of this paper is to inquire into the consequences of this argument in order to check whether they are devastating to the initial position. The main focus will be the question of whether type epiphenomenalism, the alleged consequence of the causal exclusion argument, really leads to eliminativism about the mental. In order to cast some doubt on this claim I use David Lewis’s distinction between sparse and abundant properties and draw a comparison between mental predicates and deflationary truth. The conclusion is that the causal exclusion argument doesn’t lead to eliminativism as traditionally conceived and some of Kim’s theses might in fact be approved by non-reductive physicalists.

1 The Causal Exclusion Argument

Non-reductive physicalism, as formulated, among others, by Davidson (1970) and Fodor (1974), used to be the dominant position in analytical metaphys- ics of mind for a couple of decades. The basic tenet of all various forms of this position is the conjunction of two theses: first, the token identity thesis— i.e. the belief that all particular mental beings or events are identical to some physical beings or events, and second, the rejection of type identity thesis: non-reductive physicalists claim that mental types cannot be identified with physical ones. These two claims are usually supplemented with some appeal to the notion of supervenience (e.g. Davidson 1970), which is meant to exclude the possibility of certain forms of property dualism. The metaphysical appeal of such a position is fairly obvious—it allows us to claim that on the fundamental level there is only one kind of widely under- stood “stuff” and thus avoid the problems which haunted traditional forms of

1 Earlier versions of this paper were presented at LOGOS special Colloquim in Barcelona, The Varieties of Realism/Antirealism conference in Rużomberk, Slovakia, and The Polish-Scottish Philosophy Conference in Warsaw. I’m very grateful to the audiences for helpful comments. Special thanks to David Pineda and Jędrzej Grodniewicz.

From Epiphenomenalism To Eliminativism? 193 substance dualism. On the other hand, we are able to save the autonomy of the mental and steer clear of the pitfalls of the radical reductionist program. Kim (1993b) wanted to show that such a position, although attractive, is untenable, because if it were true it would be impossible to account for mental causation. This is the point of Kim’s famous causal exclusion argument.2 The basic structure of the argument (which is repeated by Kim in many of his papers) was succinctly presented by Jasper Kellstrup (2006). He identified two main premises of the argument. The first is the Completeness thesis: “ Every physical effect has a sufficient physical cause” (Kallestrup 2006, p. 463). The second one is Exclusion: “If a property E has a sufficient cause C, then no other property C* distinct from C can be a cause of E” (Kallestrup 2006, p. 464). These two premises, combined with the tenets of non-reductive physicalism lead us to the conclusion that non-reductive physicalism “permits mental properties no causal role, not even in relation to other mental properties” (Kim 1993b, p. 270). Let’s take one example: we might want to say that my opening of a fridge (a physical event) was caused by my thinking that there is some food left there (a mental event). But, if we accept token identity, my thought (as a singular event) is identical with some individual physical event. This physical event is causally responsible for my behavior, but, as Kim insists, only physical properties of this event are relevant in providing a causal explanation of my behavior. The fact that this event possesses some mental properties (as well as physical) is completely irrelevant, due to the exclusion principle. So, whenever we want to give an account of causal history of any event, we don’t need to invoke any mental properties. This is the thesis of “type epiphenomenalism”: mental events don’t enter causal relations in virtue of their mental properties. The argument has been subject to many analyses and objections (notable lines of criticism include the one presented by Yablo (1992) and the ones based on so called manipulative theories of causation (see e.g. Menzies 2008)), so I won’t elaborate on it any further. Instead I shall focus on the problem of whether type epiphenomenalism really is such a disastrous consequence for the non-reductive physicalism. There are at least two kinds of arguments that aim to show that type epiphenomenalism is unacceptable. One is based on the claim that this position is in evident contradiction to our everyday experience (Kim 1998, p. 32). I shall not venture into this problem, but let me just note, that there is some dissent against this position (see, for example, Bieri 1992). Instead, I’m going to focus

2 It’s worth noting that a very similar argument was formulated earlier by Malcolm (1968), but with the opposite intention—Malcolm was using this reasoning to criticize “mechanicism,” a view broadly similar to reductionism. Kim, obviously, gives due credit to Malcolm.