Online research in philosophy

This paper identifies and critiques a theory of mental causation defended by some proponents of nonredutive physicalism that I call “intralevelism.” Intralevelist theories differ in their details. On all versions, the causal outcome of the manifestation of physical properties is physical and the causal outcome of the manifestation of mental properties is mental. Thus, mental causation on this view is intralevel mental to mental causation. This characterization of mental causation as intralevel is taken to insulate nonreductive physicalism from some objections to nonreductive physicalism, including versions of the exclusion argument. This paper examines some features of three recent versions of intralevelism defended by John Gibbons, Markus Schlosser, and Amie Thomasson. This paper shows that the distinctive problems faced by these three representative versions of intralevelism suggest that the intralevelist strategy does not provide a viable solution to the exclusion problem.

Jaegwon Kim and others have claimed that (strong) psychophysical supervenience entails the reducibility of mental properties to physical properties. I argue that this claim is unwarranted with respect to epistemic (explanatory) reducibility (either of a global or of a local sort), as well as with respect to ontological reducibility. I then attempt to show that a robust version of nonreductive materialism (which I call supervenient token-physicalism) can be defended against the charge that nonreductive materialism leads to epiphenomenalism in failing to account for the causal or explanatory relevance of mental properties.

A well-known ``overdetermination''argument aims to show that the possibility of mental causes of physical events in a causally closed physical world and the possibility of causally relevant mental properties are both problematic. In the first part of this paper, I extend an identity reply that has been given to the first problem to a property-instance account of causal relata. In the second, I argue that mental types are composed of physical types and, as a consequence, both mental and physical types may be causally relevant with respect to the same physical effect, contrary to the overdetermination argument. In further sections, I argue that mental types have causal powers, consider some objections and reject an alternative version of part-whole physicalism. Throughout I assume that causal relata are tropes and property types are classes of tropes.

Non-reductive physicalists are increasingly regarded as unwitting epiphenomenalists, since their refusal to reduce mental features to physical properties allegedly implies that while there are mental causes, none of these causes produces its effects in virtue of being the type of mental state that it is. I examine, and reject, the “trope” response to this charge. I take the failure of the trope model of causal relevance to be instructive, since it illustrates a confusion that lies at the heart of the concept of causal relevance, a concept that is central to the criticism of non-reductive physicalism. By identifying this confusion, I hope to dispel the notion that non-reductive physicalism carries any commitment to epiphenomenalism.

In numerous papers Jaegwon Kim argues that nonreductive materialists (i.e., those philosophers who believe that there are no irreducible non-physical objects in the universe, and yet there are irreducible psychological properties which are indispensable in intentional psychological explanations) face two problems. One is that intentional mental properties are not causally relevant; the other is that explanations appealing to these properties are excluded by explanations appealing to physical, in particular, microphysical, properties.1 The first problem can be called the problem of epiphenomenalism. The second problem is what Kim calls the problem of explanatory/causal exclusion. Epiphenomenalism is not just a problem for nonreductive materialists, but a problem for psychology (as a science of psychological explanation), and for anyone who believes that our thought is the cause of our action. Kim argues that the exclusion problem, on the other hand, is especially a problem for nonreductive materialists. Nonreductive materialists typically buy into the principle of the causal closure of the physical domain, according to which "any physical event that has a cause at time t has a physical cause at t..... [I]f we trace the causal ancestry of a physical event, we need never go outside the physical domain." [Kim 1989b, p. 280] One cannot reject this principle unless one is willing to go back to Cartesian dualism. But the problem is, if all causation is done at the physical level, then there is no causal work left for mental kinds. If mental kinds do not play any causal role, then intentional psychological explanations that appeal to mental properties are not warranted. Therefore, Kim concludes, nonreductive materialism is an untenable position. Some nonreductionists (Davidson, Dretske, LePore & Loewer, Jackson & Pettit, for example) have tried to argue for the causal relevancy of mental properties from an..

Throughout the 1990s, Jaegwon Kim developed a line of argument that what purport to be nonreductive forms of physicalism are ultimately untenable, since they cannot accommodate the causal efficacy of mental states. His argument has received a great deal of discussion, much of it critical. We believe that, while the argument needs some tweaking, its basic thrust is sound. In what follows, we will lay out our preferred version of the argument and highlight its essential dependence on a causal-powers metaphysic, a dependence that Kim does not acknowledge in his official presentations of the argument.i We then discuss two recent physicalist strategies for preserving the causal efficacy of the mental in the face of this sort of challenge, strategies that (ostensibly) endorse a causal powers metaphysics of properties while offering distinctive accounts of the physical realization of mental properties. We argue that neither picture can be satisfactorily worked out, and that seeing why they fail strongly suggests that nonreductive physicalism and a causal powers metaphysic are not compatible, as our original argument contends. Since we also believe that robust realism concerning mental causation should not be abandoned, we take the argument of this paper to strongly motivate an account on which the mental is unrealized by and ontologically emergent from the physical. In a final section, we sketch what an ontologically emergentist account of the mental might look like.

Semifactuals and Epiphenomenalism

Mental properties are said to be epiphenomenal because they do not pass the counterfactual test of causal relevance. Jacob (1996) adopts the defence of causal efficacy of mental properties developed by LePore and Loewer (1987). They claim that those who argue for the epiphenomenalism of the mental place too strong a requirement on causal relevance, which excludes causally efficacious properties. Given a proper analysis of causal relevance, the causal efficacy of mental properties is saved. I defend the counterfactual test and epiphenomenalism of the mental against this critique. In causal counterfactuals we hold everything the same, take out the causal property and see if the effect property occurs. We do not replace the causal property with a barely different property as presupposed by LePore and Loewer. But I recognize some general problems in making counterfactual claims about mental events, which raise doubts about the usefulness of the counterfactual test in general.

Most philosophers of mind nowadays espouse two metaphysical views: Nonreductive Physicalism and the causal efficacy of the mental. Throughout this work I will refer to the conjunction of both claims as the Causal Autonomy of the Mental. Nevertheless, this position is threatened by a number of difficulties which are far more serious than one would imagine given the broad consensus that it has generated during the last decades. This paper purports to offer a careful examination of some of these difficulties and show the considerable efforts that one has to undertake in order to try to overcome them. The difficulties examined will concern only metaphysical problems common to all special science properties but not specific of mental properties. So, in proposing a functionalist version of Nonreductive Physicalism in what follows, I will not attempt to answer to well known objections such as the absent qualia argument and the like. This should not be interpreted as a limitation! in the scope of this work. On the contrary, in dealing with more general objections we will try to evaluate a position which entails (under common assumptions) the Causal Autonomy of the Mental, namely: Nonreductive Physicalism plus the causal efficacy of special science properties.

Nonreductive physicalism is currently one of the most widely held views about the world in general and about the status of the mental in particular. However, the view has recently faced a series of powerful criticisms from, among others, Jaegwon Kim. In several papers, Kim has argued that the nonreductivist's view of the mental is an unstable position, one harboring contradictions that push it either to reductivism or to eliminativism. The problems arise, Kim maintains, when we consider the causal powers that mental properties are held to carry on the nonreductivist's view and the causal transactions into which mental events are said to enter. My aim here is less than that of defending nonreductive physicalism against all of Kim's criticisms. I wish primarily to call into question the claim that nonreductive physicalism is committed to emergentism with respect to the causal powers of the mental. As subsidiary points, I shall offer a limited defense of nonreductivism against two related objections that Kim raises. However, even if my conclusions are correct, problems remain for the nonreductivist's treatment of mental causation. I shall close the paper with a brief discussion of these difficulties.

Frank Jackson and Philip Pettit have defended a non-reductive account of causal relevance known as the ‘program explanation account’. Allegedly, irreducible mental properties can be causally relevant in virtue of figuring in non-redundant program explanations which convey information not conveyed by explanations in terms of the physical properties that actually do the ‘causal work’. I argue that none of the possible ways to spell out the intuitively plausible idea of a program explanation serves its purpose, viz., defends non-reductive physicalism against Jaegwon Kim’s Causal Exclusion Argument according to which non-reductive physicalism is committed to epiphenomenalism because irreducible mental properties are ‘screened off’ from causal relevance by their physical realizers. Jackson and Pettit’s most promising explication of a program explanation appeals to the idea of invariance of effect under variation of realization , but I show that invariance of effect under variation of realization is neither necessary nor sufficient for causal relevance.