Physicalism nonreductive

After the initial hype about supervenience being the answer to a form of nonreductive physicalism, it was realized that it delivered no goods, and in the past few years inter-... 

Bechtel. W., Richardson, R. C. 1992. "Emergent Phenomena and Complex Systems." In A. Beckermann, H. Flohr, J. Kim, eds. Emergence or Reduction Essays on the Prospects of Nonreductive Physicalism (pp. 257-288). Berlin de Gruyter. 

Davidson s anomalous monism is usually thought of as a version of nonreductive physicalism. But its commitment to physicalism may be rather weak because, though Davidson does endorse the causal closure of physics, it is not clear that he agrees with the supervenience claim I call Jackson-Lewis physicalism since he denies that there are tight connections between the mental and the physical. 

Physicalism comes in two varieties reductive physicalism (RP) and nonreductive physicalism (NRP). RP claims contrary to (3) that every real, or as I will say genuine, property (G-property) that has instances in our world (or any physically possible world) is identical to a physical G-property. NRP claims that some mental properties are G-properties that are not identical to any physical G-properties. If events are, as Kim and I think, instantiations of G-properties, then there are mental events that are not identical to physical events but that are nonetheless real. Mental causation says that some of these mental events cause physical events. It is pretty obvious that NRP is committed to causal overdetermination. Later, we will look at how Kim formulates an argument that makes this commitment explicit and attempts to refute it. 

A view that has been gaining popularity is that we can appeal to the idea of realization to explain how mental events (exemplifications of mental properties) can be causes without being physical events (exemplifications of physical properties). The idea that mental properties are realized by physical properties is not new. ° But Kim s work on the problem of mental causation seems to have played a major role in inspiring the recent spate of attempts to appeal to physical realization to explain how mental causation is possible. Kim (1998b) labels this viewpoint realization physicalism, but it is also sometimes called nonreductive physicalism. For reasons that should be clear in due course, I will call it nonreductive realization physicalism. The core of the view is this ... 

Bechtel, William, and Robert Richardson. 1993. Emergent phenomena and complex systems. In Emergence or reduction Essays on the prospects of nonreductive physicalism, ed. Ansgar Beckermann, Hans Flohr, and Jaegwon Kim, 257-288. Berlin de Gruyter. 

Bartlett, J. (2010a). A critique of nonreductive physicalism. Phillips Theological Seminary, Tulsa, OK. Unpublished Master s Integrative Paper. 

Although there are different variations of both reductive and nonreductive materialism, reductionists typically hold that mental properties can be defined in terms of or reduced to physical properties. Nonreductive materialists, on the other hand, typically hold that while all mental properties supervene on physical properties, mental properties can neither be defined in terms of nor reduced to physical properties. 

This dissertation begins by discussing an issue that is central to all nonreductive materialist views - the problem of anomalous monism. Any nonreductive materialist view that does not want to accept the epiphenomenalism of mental properties must be able to show how irreducible mental properties can be causal properties. If the irreducibility of mental properties implies that there are no strict laws connecting mental properties to physical properties, then the question we must try to answer is how anomalous mental properties can be causal properties. In my first chapter, I submit an account of how anomalous mental properties can be causal properties. I argue that even if all events are backed by strict laws, strict laws do not always capture an event s unique causal properties. Thus, strict laws do not rule out irreducible anomalous mental properties as also being causally potent. 

Notice that type-identity materialists do not have to worry about the issue of psycho-physical causal laws, since type-identity materialists hold that there are no irreducible higher-level properties. However, all nonreductive materialist views must... 

This is true, since it is central to nonreductive materialism that there are no strict psycho-physical causal laws. If there were strict psycho-physical causal laws, then we would be able to reduce the mental to the... 

This type of objection to nonreductive materialism is central to the work of Jaegwon Kim. Kim discusses this objection extensively in the various versions of his exclusion argument or supervenience argument. He holds that the only way to give mental properties a causal role is to functionally reduce them to physical properties, since physical causation will always rule out causation in virtue of irreducible mental... 

This objection does not rely on the assumption that all events of causation are backed by strict laws. Certainly one can argue that if all events of causation are backed by strict laws, then the strict law (at the level of physics) will always give us what we need for causation and leave no causal work for mental properties to do. But one could also make a similar argument that irreducible mental properties will always be epiphenomenal, since we can always describe the causation in physical terms. Whether our description in physical terms is in the form of a strict law or not, the essence of die objection remains the same. See chapters 2 and 3 ahead for more on this type of objection to nonreductive materialism. 

This line of objection to nonreductive materialism again is the type of objection that Kim makes in his discussion of the exclusion argument. In chapters 3 and 4 to come, I discuss this objection in further detail and argue that we have no good reason to think that all or even most scientific properties are reducible to the properties of physics. Thus, if causation at the level of physics does not rule out causation in virtue of irreducible higher-level scientific properties, then we have no good reason to think that it should rule... 

If we hold on to this principle and we are nonreductive physicalists who hold that mental properties are distinct from and irreducible to physical properties, then we might end up with the unappealing consequence that mental properties are causally impotent. 

This principle could be taken to mean that every good causal story we can tell has to be couched in physical terms or that all causation is always in virtue of physically definable or reducible properties. Taken this way, however, this principle would just beg the question against nonreductive materialism. Under physical causal closure, it is not that we can never invoke physically irreducible higher-level properties as causes for a physical event. We may very well cite some irreducible mental property as the cause of some physical event. The point is that this mental property, if it is to be causal, must somehow be anchored in the physical world. It must be tied to the physical by some sort of supervenience or realization relation. This close tie to the physical will always make it possible, in principle, for us to tell a causal story in terms of physical properties, even though the best causal story might not always refer only to physical properties. Thus, we will never be forced to go outside the physical domain and refer to physically irreducible properties in order to find a sufficient cause for a physical event. So the principle of physical causal closure requires that if we pick any physical event, it will always be possible, in principle, for us to find a purely physical causal chain for that event. So if we take any physical event P, we should be able to find some property or group of properties P, such that P is physical and P is a sufficient cause for P. ... 

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... 

Notice that this is the same type of move that saves event causation for anomalous monism. Mental events are causal because each token mental event is identical with a physical event. The problem of property causation, however, is a challenge posed by the exclusion principle that the nonreductive... 

As simple and elegant as the above solution may seem, it is neither available to nor desirable for the nonreductive materialist. Although a Davidsonian anomalous monism can solve the problem of event causation, the nonreductivist still must give some account of property causation. Nonreductive materialists hold that mental properties are distinct from and irreducible to physical properties. So the nonreductivist cannot just reduce mental property M to physical property P and say that M causes P because it is really identical with or reducible to P. The nonreductivist needs to show how it is that both M and P, even though they are distinct properties, can be causally efficacious with respect to P. ... 

This version of the exclusion principle seems quite plausible, with not much argument needed to convince us of its truth. It seems right to say that two distinct events cannot both be causes of e, if one of the events is a sufficient cause of e (and it is not a case of overdetermination). But notice that Kim here speaks in terms of events rather than properties. It is not clear why Kim does this here, since on a Davidsonian model of nonreductive materialism, the mental and physical events would be token identical and would not be two distinct events. What we would have is a single event with distinct mental and physical properties. 

Now notice here that Kim refers to events and not properties in his statement of strong closure. If Kim were really just talking about events here, then strong closure would be completely uncontroversial and rmproblematic for any materialist. Nonreductive materialists could hold on to a Davidsonian anomalous monism, and hold that all causes of physical events are themselves physical events. This would still leave open the possibility that these physical events could have physically irreducible properties that are sometimes causally potent. 

Thus, except for the brief mention of strong closure here, Kim chooses to rely on his weaker notion of closure - i.e. that closure implies only sufficient, but not exclusive, physical causation - in his arguments against nonreductive materialism. Therefore Kim says that physical causal closure does not by itself exclude nonphysical causes, or causal explanations, of physical events (2005 17). According to Kim, it is only when we adopt the exclusion principle in conjunction with closure that nonphysical causes get excluded (2005 17). So Kim does not seem to rely on a view like strong closure or exclusive closure. Kim seems to hold a more standard view that we can accept for our purposes -i.e., that physical causal closure implies that all particular physical events with causes have sufficient physical causes and sufficient physical causal explanations. 

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. 

Descartes s difficulties arose from the duality of mental and material substances. Current mainstream physicaUsm, which calls itself nonreductive physicahsm, runs into parallel difficulties on account of its commitment to the duality of psychological and physical properties — or its failure to make a reductionist commitment for psychological properties, (p. 46)... 

Nonreductive realization physicalism (NRP) No mental event is a physical event, but every mental event is realized by some physical event or other. 

What is supposed to make the view nonreductive is that mental events are not identical with physical events. What is supposed to make it a... 

Cynthia Macdonald and Graham Macdonald (1995, 2006) have a view very similar to this. They hold a type of physicalism that is nonreductive in that mental properties are not identical with physical properties, yet mental events are causes since instances of mental properties are physical events. (They thus do not count as NRP theorists.)... 

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