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Orthodox physicalism has a problem with mental causation. If physics is complete and mental events are not identical to physical events (as multiple-realisation arguments imply) it seems as though there is no causal work for the mental to do. This paper examines some recent attempts to overcome this problem by analysing causation in terms of counterfactuals or conditional probabilities. It is argued that these solutions cannot simultaneously capture the force of the completeness of physics and make room for mental causation.

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..

In this note, I will discuss one issue concerning the main argument of Mind in a Physical World (Kim, 1998), the Causal Exclusion Argument. The issue is whether it is a consequence of the Causal Exclusion Argument that all macro level causation (that is, causation above the level of fundamental physics) is an illusion, with all of the apparent causal powers of mental and other macro properties draining into the bottom level of physics. I will argue that such a consequence would give us reason to reject the Causal Exclusion Argument. But there is also a stronger challenge, the charge that, if there is no bottom level of physics, the Causal Exclusion Argument has the consequence that “causal powers would drain away into a bottomless pit and there wouldn’t be any causation anywhere.” (81--page numbers that are not attributed to other works are to Kim, 1998).

There are important cases where properties not referred to by expressions from the languages of physics are enabled in certain times and circumstances to get causal control over some kinds of physical events. I will argue that in those cases we would have to transfer to those properties the causal sufficiency to bring about these events. This would offer a principle of causal inheritance in sharp contrast with the inheritance principle for the causal sufficiency of second order properties defended by Jaegwon Kim in his recent discussion of the causal exclusion problem concerning mental properties. The two principles would be very different. Their domains of application would be distinct. Kim's principle would transfer causal sufficiency to the more "concrete" physical properties able to realize mental properties understood as second order properties. Our principle would transfer causal sufficiency to the more "general" properties able to cause the relevant physical effects in the times and circumstances in question. That way, it would be possible to give a quite simple answer to the problem of causal exclusion posed by Kim in relation to mental properties. Our approach also would have very important consequences in relation to ordinary macrophysical causation.

We have a familiar idea of levels of description or levels of theory in science: microphysics, atomic physics, chemistry, biology, psychology, and the various social sciences. It is clear that philosophers - such as Terry Horgan - who want to be nonreductive materialists with regard to the mental must hold that this is not mere description; there must be genuine higher-level causes, and hence, genuine higher-level properties, in particular mental properties and causes. But there appears to be a deep problem concerning mental causes. The (micro-) physical world is causally closed. Mental states are - or depend on or are realized by - physical states. It seems, then, that the physical state on which a mental state depends will be responsible for any alleged effects of the mental state. There will be no room for mental causation. And if properties exist insofar at they have a causal role, there will be no room for mental properties either. Many philosophers - Horgan included - have seen this problem of the "causalexclusion" ofthe mental as a specialcase of a general problem:the exclusion of higher-level causes by the causal closure of microphysics. Suppose one higher-level state, H1 leads to another higher-level state, H2. H1 is realized by some base level state, B1, which leads to a base-level state, B2, which in turn realizes H2. All of the casual work, so to speak, takes place at the base level. There is no room for any genuine causal connection between H1, as such, and H2, as such. I argue that there is no problem about higher-order causation in general. There are genuine, unsurprising higher-level causes and properties. A ball roles, for example, or breaks a window. If there is a problem of exclusion regarding putative mental causes, it is not an instance of a general exclusion problem, but is sui generis, and mental causation remains mysterious.

The anti-reductionist who wants to preserve the causal efficacy of mental phenomena faces several problems in regard to mental causation, i.e. mental events which cause other events, arising from her desire to accept the ontological primacy of the physical and at the same time save the special character of the mental. Psychology tries to persuade us of the former, appealing thereby to the results of experiments carried out in neurology; the latter is, however, deeply rooted in our everyday actions and beliefs and despite the constant opposition of science still very much alive. Difficulties, however, arise from a combination of two claims that are widely accepted in philosophy of mind, namely, physical monism and mental realism, the acceptance of which leads us to the greatest problem of mental causation: the problem of causal exclusion. Since physical causes alone are always sufficient for physical effects mental properties are excluded from causal explanations of our behaviour, which makes them “epiphenomenal”. The article introduces Van Gulick’s solution to the exclusion problem which tries to prove that physical properties, in contrast to mental properties, do not have as much of a privileged status with respect to event causation as usually ascribed. Therefore, it makes no sense to say that physical properties are causally relevant whereas mental properties are not. This is followed by my objection to his argument for levelling mental and physical properties with respect to causation of events. I try to show that Van Gulick’s argument rests on a premise that no serious physicalist can accept.

In his work, Horgan argues for the compatibilism of agency, mental state-causation, and physical causal-closure. We generally assume a causally closed physical world that seems to exclude agency in the sense of mental state-causation in addition to physical causation. However, Horgan argues for an account of agency that satisfies the experience of our own as acting persons and that is compatible with physical causal-closure. Mental properties are causal properties but not identical with physical properties because there are different ontological levels. In this commentary, I shall reconsider the essential issues of this compatibilism (1), focus on a problem for Horgan’s conception of agent causation that arises from the causal argument for ontological reductionism (2), and propose to embed Horgan’s conception of agency within a reductionist approach in order to vindicate the indispensable character of agency (3).

In this brief note I claim that, contrary to what Esfeld argues in his paper in this same volume, Kim's position with respect to the problem of causal exclusion does indeed commit him to the causal heterogeneity of realized properties.

I argue that an independently attractive account of causation and causal explanation provides a principled resolution of the exclusion problem.

It is quite obvious why the antireductionist picture of mental causation that rests on supervenience is an attractive theory. On the one hand, it secures uniqueness of the mental; on the other hand, it tries to place the mental in our world in a way that is compatible with the physicalist view. However, Kim reminds us that anti-reductionists face the following dilemma: either mental properties have causal powers or they do not. If they have them, we risk a violation of the causal closure of the physical domain; if they do not have them, we embrace epiphenomenalism, which denies any sort of causal powers to the mental. So, either we violate the causal closure of physics, or we end up with epiphenomenalism. The first two sections of the article describe the problem of causal exclusion and Kim’s causal dilemma. The last two introduce Horgan’s antireductionist answer and my objection to that answer.