Mental causation

Thinking Causes. In Mental Causation. Ed. by J. Heil and A. Meele. Oxford Clarendon Press,. 

Davidson, D. 1993. Thinking Causes. In J. Heil A. Mele, eds. Mental Causation (pp. 3-18). Oxford Clarendon. 

In the ubiquitous arguments from overdetermination, it is often an unacknowledged premise the existence of genuine mental causation could not imply overdetermination unless the physical structure of the world is already sufficient to determine the course of physical events, to the extent that they are determined. 

The science of psychology, which attempts to predict and explain human behavior in terms of mental states, is committed to the idea that mental states causally influence behavior. If mental states do not cause behaviors, then behaviors caimot be explained in terms of mental states. As Kim says, A science that invokes mental phenomena in its explanations is presumptively committed to their causal efficacy for any phenomenon to have an explanatory role, its presence or absenee in a given situation must make a difference - a causal difference (1998 31). If we cannot account for mental causation, then it seems we also lose human agency and the science of psychology as explanatory science. A good account of mental causation is thus an indispensable part of any successful theory of mind. 

That is, any theory of mind that does not resort to eliminativism or epiphenomenalism must be able to give an account of mental causation. I am in agreement with Kim that both eliminativism and epiphenomenalism are problematic and ultimately fail as theories of mind. I will not, however, directly discuss my reasons for rejecting eliminativism and epiphenomenalism in this paper. 

Thus, Davidson s claim that supervenience saves mental causation falls short. Davidson is wrong to think that the question, hi virtue of which properties did event A cause event B makes no sense. To save AM fi om the epiphenomenalism of mental properties, we need a way to show how it is possible for causation to be in virtue of mental properties. The question is whether the anomalism of the mental will make it impossible for mental properties to be the one s in virtue of which events are causes. 

Thus, the fact that there are no strict psycho-physical causal laws should not rule out the causal efficacy of mental properties. The fact that we cannot cite mental properties in our strict laws does not mean that mental properties cannot be causal properties. Biological properties are not eited in strict laws, but yet they are the types of properties we think of as eausal in seience. Strict laws wiU always (or at least almost always) be in terms of physies, yet there are many properties at higher levels of organization that we believe to be causal properties. These considerations seem to leave open the possibility that mental properties too eould be eausal, even though they ean never be cited in strict laws. This, of course, does not prove that mental properties are causal properties. What it does show is that the anomalism of the mental does not rule out the causal efficacy of mental properties. More needs to be said on this subject before a positive account of mental causation can emerge. But at least now, we are in a position where we can begin to set forth a theory of how irreducible mental properties could be... 

At the very least, M and P must be related by supervenience. However, it may be that mere supervenience is not enough to give us an adequate accoimt of mental causation within a physicalist framework. We might want to hold a view like Davidson s, where not only does M supervene on P, but P realizes M, and M and P are properties of a single event. So as properties, M and P are distinct, but as event, M and P are token identical. Whether physicalism requires mere supervenience, a picture like Davidson s with realization and event identity, a functional reduction of M to P as Kim advocates, or a fullblown type identity of M and P will be discussed shortly. 

Now how does all of this pose a problem for nonreductive materialism Nonreductive materialism holds that although every mental property supervenes on some physical property (and is possibly also realized by tiiat physical property and token identical with it as event), mental properties are neither type identical with nor reducible to physicjd properties. Now in order to give an adequate account of mental causation, the nonreductive materialist will need to be able to say how it is that mental events can be causally potent - i.e., how can a mental event M cause another mental event M to occur, and how can a mental event M cause a physical event P to occur Now if we are working with a Davidsonian model and we have token identity, where every mental event is token identical with its physical instantiation base, then there is no problem with event causation. Mental events are causal because theyjust are physical events. But the... 

Kim asks us to consider the following scenario of mental-to-mental causation, where M and M are mental properties ... 

Thus, if we accept mind-body supervenience, then any case of mental- to-mental causation will presuppose the existence of mental-to-physical causation (Kim 1998 43). 

Since Kim thinks it is implausible that every case of mental causation is a case of overdetermination (for reasons I will discuss shortly), Kim asks us to assume that this is not a case of causal overdetermination. So ... 

If these are the only kinds of cases that can be called cases of causal overdetermination, then Kim is right that it is absurd to think that all cases of mental causation are cases of overdetermination. If we use the term overdetermination as Kim seems to here, then we should reject the idea that P is causally overdetermined by M and P. Surely M and P are not completely independent and individually sufficient causes for P. Rather, M and P are related by supervenience (and possibly also by realization and event identity as well). It is not as if M could have caused P even if P had not occurred. If P had not occurred, M would not have occurred either - M depends on P for its existence. Thus, it seems plausible to accept premise (7) in Kim s exclusion argument - i.e. that P is not causally overdetermined by M and P. 

The idea here is that if the exclusion principle is right and really rules out mental causation, it will also rule out other types of macrocausation and supervenient causation, and the only causation we will be left with will be at the most basic microphysical level. 

Of course on my view of mental causation, whether closure occurs at all is irrelevant, since I reject the exclusion principle and therefore do not face seepage or... 

Once the exclusion principle has been rejected, then we no longer have any reason to reject nonreductive materialism on the grormds of exclusion. Furthermore, the most plausible alternative to nomeductive materialism - Kim s functional reduction - cannot be defended, since there is strong evidence in favor of the context dependence of scientific (and mental) properties. So at this point, nonreductive materialism seems to be the most viable option for a successful theory of mental causation. Let us now turn to some positive reasons for accepting a nomeductivist view of mental causation. 

In this chapter, I will argue for three claims, which together offer positive support for a nonreductivist view of mental causation. First, 1 will defend what John Norton has called a material theory of induction. This type of view, which has been endorsed by multiple philosophers, holds that successful inductive inferences rely on having the appropriate background assumptions and empirical knowledge in the relevant domain of inquiry. 

It is clear that higher-level properties play an indispensable role in our inductive inferences. This supports the idea that the causal mechanism is also often at the higher level. Nonreductive materialism embraces this idea. It recognizes the fact that causation can occur at multiple levels of realization and that part of telling the best causal story is finding the appropriate level of causation and causal explanation. Good philosophy of science seems to tell us that causation can occur at multiple levels. Nonreductive materialism can subsume mental causation under an account of higher-level causation within the sciences. 

Good philosophy of science tells us that since the best predictions and causal explanations are often found at the higher level, the causal mechanisms responsible for events are also often at the higher level. If we look to real scientific methodology to guide us in how we ought to study mental causation, it is clear that we must look at how we best predict and explain behavior in order to best identify the real cause of our behavior. 

Many of our best predictions and explanations of human behavior come at the higher level of beliefs, desires, and intentions. If we take our cue from philosophy of science, then we want to say that these irreducible higher-level properties are causal properties. We do not need to reduce these mental states to neurological states. Just as real scientific explanations occur at multiple levels of explanation, and just as irreducible higher-level properties are causal in scientific practice, such is often the case with mental causation. Mental causation is just another case of higher-level causation. And just as the causal mechanism often occurs at higher-levels in science, so it often occurs at the level of irreducible mental properties. 

Thus far, I have criticized reductionism, specifically, Kim s functional reduction and the exclusion principle which motivates it. I have also set forth some positive reasons for accepting a nonreductive materialist view of mental causation. I have tried to draw upon some of the lessons that good philosophy of science tells us and subsume mental causation under a general view of higher-level causation. 

Aecepting nonreductive materialism gets us what we want and need out of a theory of mental causation. We can have sufficient causation at the physical level and causation in virtue of irreducible mental properties, without any sort of problematic overdetermination. We can account for both the multiple realizability and the context dependence of many mental properties. And we can account for why mental explanations often seem to offer us better predictive and explanatory power than lower level physical ones. Mental explanations work because menial properties are causal properties. 

It seems to me that one of the most (if not the most) important things we need from a theory of mind is a good account of mental causation. If we think that the science of psychology, whose job it is to predict and explain human behavior, is a legitimate science, then we need it to be the case that mental properties are causal, fri addition, a great part of our survival as social creatures in this world depends on our ordinary assessment of one another s mental states and our assumption that those mental states are causally responsible for behavior. We regularly make predictions about what others are going to do and offer explanations of why others have behaved as they have based on our belief that mental states cause behaviors. If we want to retain the independently plausible idea that predictions and explanations of behavior in terms of mental states work because mental states are causal, then we need to account for how it is that mental states can be causal. 

It seems to me that, other things being equal, whatever theory of mind can offer the best account of mental causation will be the most plausible theory to accept. What I have tried to do is show that nonreductive materialism does the best job of accounting for how it is that mental properties can be causal properties. 

I also have not seriously entertained the view of eliminative materialism. I take it to be an undeniable fact about the world and about human beings that mental states are real. I suppose it would be possible for someone to try to deny this fact, but I don t see how this view could possibly be defended, nor do I think anyone has ever come close to being able to successfully defend this idea. Someone who adamantly denied the existence of mental states would find my entire project to be fruitless. My goal is to show how mental properties ean be causal properties. If there are no such things as mental properties, then everyone s efforts to try to account for mental causation (including my own) have been for nothing. So much for eliminative materialism. 

If we want to account for mental causation and reject epiphenomenalism, then we are left with reductive materialism or nonreductive materialism. The question is, which view will do the best job at accounting for mental causation ... 

Since these are the crucial issues in the debate, my argument against ftmctional reduction and for nonreductive materialism is two-fold. First I argue against the exclusion argument. If I am successful, then what I have done is left nonreductive materialism as a viable option. The purpose of the exclusion argument is to show that nonreductive materialism cannot account for mental causation because it cannot make irreducible mental properties causal. If the exclusion argument worked, then we would... 

This leaves us with epiphenomenalism (which we don t want) and nonreductive materialism as viable options. If my arguments against exclusion and for context dependence are successful, then what I ve done in my first four chapters is show that nonreductive materialism gives us the most promise at being able to aeeount for mental causation. 

I have tried to defend nonreductive materialism as the most plausible view. It is the view that I think does the best job at offering a good accoimt of mental causation -one which accords well with our ordinary and scientific conceptions of causation. There are, however, limits to what I have tried to do. 

If I am right, and some version of nonreductive materialism is the right way to understand mental causation, then where does that leave us What are the consequences of this view How might this type of view inform the fields of philosophy of mind and philosophy of science ... 

Even if all philosophers decided to embrace some form of reductionism, the world around us would still continue to operate on the implicit assumption that irreducible higher-level properties are causal. But if we re looking for a theory of mind and a theory of mental causation that accurately describes how the mind interacts with the world around it, it is a virtue for this theory to accord with the way the world seems to actually work. The evidence is all around us that higher-level inductive inferences and causal explanations succeed. Reductionism has to try to somehow explain away or downplay this fact. Nonreductive materialism, on the other hand, expects this to be the case and can account for why higher-level inductive inferences and causal explanations work. 

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