Causal Powers and the Necessity of Realization

Non-reductive physicalists hold that mental properties are realized by physical properties. The realization relation is typically taken to be a metaphysical necessitation relation. Here, I explore how the metaphysical necessitation feature of realization can be explained by what is known as ‘the subset view’ of realization. The subset view holds that the causal powers that are associated with a realized property are a proper subset of the causal powers that are associated with the realizer property. I argue that the said explanation of the metaphysical necessitation feature requires a careful treatment of the relationship between properties and causal powers.     

Three Varieties of Causal Overdetermination

Causal overdetermination worries arise in a number of domains, but most notably in the philosophy of mind. In discussions of such worries, alleged examples of causal overdetermination are uniformly viewed as prima facie problematic. While all alleged cases of overdetermination might (or might not) be problematic, I aim to show that they are so for different reasons. Examples of causal overdetermination neatly divide into three varieties, corresponding to the connections between the mechanisms and the properties of the causes. Future debates over overdetermination, and mental causation in particular, should pay heed to this distinction.     

William James on emotion and intentionality

In my reply I focus on three topics: the usefulness of Searle’s physical analogies for understanding the relationship between higher-level mental properties and lower-level physical properties, the question of overdetermination and the causal efficacy of unconscious intentional states. I argue that Searle’s reply does not refute my arguments against his analogies, while concerns about overdetermination are only taken away because his reply shows that there is no genuine unconscious mental causation in his view. That makes it hard to understand how he can maintain at the same time that we follow rules unconsciously.     

Mental Causation: Unnaturalized but not Unnatural

The central problem for a realist about mental causation is to show that mental causation is compatible with the causal completeness of physical systems. This problem has seemed intractable in large part because of a widely held view that any sort of systematic overdetermination of events by their causes is unacceptable. I account for the popularity of this view, but argue that we ought to reject it. In doing so. I show how we thereby undermine the idea that mental causes must be naturalizable in order to be legitimate. Thus I argue that a non-naturalist conception of mental causation is compatible with a plausible kind of physicalism.     

Part-Whole Physicalism and Mental Causation

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.     

Causal Exclusion and Dependent Overdetermination

Jaegwon Kim argues that unreduced mental causes are excluded from efficacy because physical causes are sufficient in themselves. One response to this causal exclusion argument is to embrace some form of overdetermination. In this paper I consider two forms of overdetermination. Independent overdetermination suggests that two individually sufficient causes bring about one effect. This model fails because the sufficiency of one cause renders the other cause unnecessary. Dependent overdetermination suggests that a physical cause is necessary and sufficient for a given effect, but it necessitates a mental cause of the effect as well. This model fails because the necessity of the mental cause renders the physical cause individually insufficient.     

A Nonreductivist Solution to Mental Causation

Nonreductive physicalism provides an appealing solution to the nature of mental properties. But its success as a theory of mental properties has been called into doubt by claims that it cannot adequately handle the problems of mental causation, as it leads either to epiphenomenalism or to thoroughgoing overdetermination. I argue that these apparent problems for the nonreductivist are based in fundamental confusion about causation and explanation. I distinguish two different types of explanation and two different relations to which they appeal: causation and determination. I argue that these types of explanation do not compete with one another, nor do these relations jointly result in overdetermination. In closing I develop a nonreductivist solution to mental causation which avoids both the hazards of epiphenomenalism and of overdetermination and so demonstrates a way to save nonreductive physicalism from the problems of mental causation.     

Contrastive mental causation

Any theory of mind needs to explain mental causation. Kim’s (upward) exclusion argument concludes that non-reductive physicalism cannot meet this challenge. One classic reply is that mental properties capture the causally relevant level of generality, because they are insensitive to physical realization. However, this reply suggests downward exclusion (if mental properties are causally efficacious, their physical realizers are causally impotent), contrary to physicalism’s assumption of closure. This paper shows how non-reductive physicalists can solve this problem by introducing a contrastive account of causation with non-exhaustive contrasts. That view has independent justification, because it is also needed to solve other puzzles. On this theory, both a mental property and its physical realizer can cause the same physical effect without lapsing into any problematic overdetermination when they cause that effect in contrast with distinct foils. This contrastive solution has advantages over previous accounts of mental causation and is defended against objections.

     

Determination,realization and mental causation

How can mental properties bring about physical effects, as they seem to do, given that the physical realizers of the mental goings-on are already sufficient to cause these effects? This question gives rise to the problem of mental causation (MC) and its associated threats of causal overdetermination, mental causal exclusion, and mental causal irrelevance. Some (e.g., Cynthia and Graham Macdonald, and Stephen Yablo) have suggested that understanding mental-physical realization in terms of the determinable/determinate relation (henceforth, ‘determination’) provides the key to solving the problem of MC: if mental properties are determinables of their physical realizers, then (since determinables and determinates are distinct, yet don’t causally compete) all three threats may be avoided. Not everyone agrees that determination can do this good work, however. Some (e.g., Douglas Ehring, Eric Funkhauser, and Sven Walter) object that mental-physical realization can’t be determination, since such realization lacks one or other characteristic feature of determination. I argue that on a proper understanding of the features of determination key to solving the problem of MC these arguments can be resisted.     

Emergence,Supervenience, and Realization

In the first section of this paper, I articulate Jaegwon Kim's argument against emergent down ward causation. In the second section, I canvas four responses to Kim's argument and argue that each fails. In the third section, I show that emergent downward causation does not, contra Kim, entail overdetermination. I argue that supervenience of emergent upon base properties is not sufficient for nomological causal relationsbetween emergent and base properties. What sustains Kim's argument is rather the claim that emergent properties realized by base properties can have no causal powers distinct from those base properties. I argue that this is false.     

GUIDELINES FOR THEORIZING ABOUT REALIZATION

Realization can be roughly understood as a kind of role‐playing, a relationship between a property that plays a role and a property characterized by that role. This rough sketch previously received only moderate elaboration; recently, however, several substantive theories of realization have been proposed. But are there any general constraints on a theory of realization? What is a theory of realization supposed to accomplish? I first argue that a view of realization is viable, in part, to the extent that physical realization under that view explains or accounts for why instances of realized properties are necessitated by how things are physically in a modally strong sense. In this sense, I claim that physical realization should explain physical supervenience. I then call into question two alternative desiderata and raise a challenge for attempts to explicate realization in terms of isomorphism or analogy. Finally, I explain how a causal‐functional account of realization, as well as less demanding accounts, can meet the preferred desideratum.     

Functionalism and Causal Exclusion

Abstract: Recent work by Jaegwon Kim and others suggest that functionalism leaves mental properties causally inefficacious in some sense. I examine three lines of argument for this conclusion. The first appeals to Occam's Razor; the second appeals to a ban on overdetermination; and the third charges that the kind of response I favor to these arguments forces me to give up "the homogeneity of mental and physical causation". I show how each argument fails. While I concede that a positive theory of mental causation is desirable, there is no reason to think that functionalism renders such a theory unattainable.     

Causal Overdetermination and Modal Compatibilism

Compatibilists respond to the problem of causal exclusion for nonreductive physicalism by rejecting the exclusionist’s ban on overdetermination. By the compatibilist’s lights there are two forms of overdetermination, one that’s problematic and another that is entirely benign. Furthermore, multiple causation by “tightly related” causes requires only the benign form of overdetermination. Call this the tight relation strategy for avoiding problematic forms of overdetermination. To justify the tight relation strategy, modal compatibilists appeal to a widely accepted counterfactual test. The argument of this paper is that the counterfactual test fails to legitimize the tight relation strategy as it fails to adequately distinguish between problematic and benign overdetermination. Contrary to modal compatibilists, modal dependence does not suffice for benignity. I conclude by arguing that adequately addressing overdetermination worries requires a much heavier metaphysical burden than modal compatibilists have typically recognized.     

Against alief

A physicalist holds, in part, that what properties are instantiated depends on what physical properties are instantiated; a physicalist thinks that mental properties, for example, are instantiated in virtue of the instantiation of physical “realizer” properties. One issue that arises in this context concerns the relationship between the “causal powers” of instances of physical properties and instances of dependent properties, properties that are instantiated in virtue of the instantiation of physical properties. After explaining the significance of this issue, I evaluate two core lines of thought that have been advanced in favor of Subset Inheritance, the view that instances of dependent properties typically have some, but not all, of the powers of physical realizers, and do not have any powers that are not also powers of physical realizers. The first argument that I address turns on our intuitive reactions to certain cases; the second appeals to the phenomenon of multiple realization. I argue that neither line of thought succeeds, and thus that insofar as we grant that an instance of a dependent property inherits some of the powers of its physical realizer, defenders of subset inheritance have not provided a compelling reason to think that it will not inherit all of the powers of its physical realizer.     

Causal Overdetermination and Kim’s Exclusion Argument

Jaegwon Kim’s influential exclusion argument attempts to demonstrate the inconsistency of nonreductive materialism in the philosophy of mind. Kim’s argument begins by showing that the three main theses of nonreductive materialism, plus two additional considerations, lead to a specific and (by now) familiar picture of mental causation. The exclusion argument can succeed only if, as Kim claims, this picture is not one of genuine causal overdetermination. Accordingly, one can resist Kim’s conclusion by denying this claim, maintaining instead that the effects of the mental are always causally overdetermined. I call this strategy the ‘overdetermination challenge’. One of the main aims of this paper is to show that the overdetermination challenge is the most appropriate response to Kim’s exclusion argument, at least in its latest form. I argue that Kim fails to adequately respond to the overdetermination challenge, thus failing to prevent his opponents from reasonably maintaining that the effects of the mental are always causally overdetermined. Interestingly, this discussion reveals a curious dialectical feature of Kim’s latest response to the overdetermination challenge: if it succeeds, then a new, simpler and more compact version of the exclusion argument is available. While I argue against the consequent of this conditional, thereby also rejecting the antecedent, this dialectical feature should be of interest to philosophers on either side of this debate.     

CAN AN APPEAL TO CONSTITUTION SOLVE THE EXCLUSION PROBLEM?

Abstract:   Jaegwon Kim has argued that unless mental events are reducible to subvening physical events, they are at best overdeterminers of their effects. Recently, nonreductive physicalists have endorsed this consequence claiming that the relationship between mental events and their physical bases is tight enough to render any such overdetermination nonredundant, and hence benign. I focus on instances of this strategy that appeal to the notion of constitution. Ultimately, I argue that there is no way to understand the relationship between irreducible mental events and their physical bases such as to both eliminate causal redundancy and preserve the efficacy of mental events.     

Properties,Powers, and the Subset Account of Realization

According to the subset account of realization, a property, F, is realized by another property, G, whenever F is individuated by a non‐empty proper subset of the causal powers by which G is individuated (and F is not a conjunctive property of which G is a conjunct). This account is especially attractive because it seems both to explain the way in which realized properties are nothing over and above their realizers, and to provide for the causal efficacy of realized properties. It therefore seems to provide a way around the causal exclusion problem. There is reason to doubt, however, that the subset account can achieve both tasks. The problem arises when we look closely at the relation between properties and causal powers, specifically, at the idea that properties confer powers on the things that have them. If realizers are to be ontically prior to what they realize, then we must regard the conferral of powers by properties as a substantive relation of determination. This relation of conferral is at the heart of a kind of exclusion problem, analogous to the familiar causal exclusion problem. I argue that the subset account cannot adequately answer this new exclusion problem, and is for that reason ill‐suited to be the backbone of a non‐reductive physicalism.     

Realization and the metaphysics of mind1

According to a familiar view in philosophy of mind, mental states or properties are realized by physical states or properties but are not identical to them. This view is often called realization physicalism. But what is realization? I argue that recent approaches to realization, represented by Carl Gillett's ‘dimensioned’ view, fail to acknowledge some textbook cases of realization. I also argue Gillett's account in particular admits realization relations that should not count if realization physicalism is to be distinguished from its competitors in the usual ways. I offer my own account of realization, and argue that it is superior not only in passing the above tests but also in its utility for answering questions about multiple realizability.     

Semantic Normativity and Semantic Causality

Semantic normativism, which is the view that semantic properties/concepts are some kind of normative properties/concepts, has become increasingly influential in contemporary meta‐semantics. In this paper, I aim to argue that semantic normativism has difficulty accommodating the causal efficacy of semantic properties. In specific, I raise an exclusion problem for semantic normativism, inspired by the exclusion problem in the philosophy of mind. Moreover, I attempt to show that the exclusion problem for semantic normativism is peculiarly troublesome: while we can solve (or dissolve) mental‐physical exclusion by adopting the so‐called ‘autonomy approach’, a similar autonomy solution to semantic exclusion is implausible if semantic properties are understood as normative properties.     

Realization, Micro-Realization, and Coincidence

Let thin properties be properties shared by coincident entities, e.g., a person and her body, and thick properties ones that are not shared. Thick properties entail sortal properties, e.g., being a person, and the associated persistence conditions. On the first account of realization defined here, the realized property and its realizers will belong to the same individual. This restricts the physical realizers of mental properties, which are thick, to thick physical properties. We also need a sense in which mental properties can be realized in thin physical properties shared by a person and her body. Defining this in turn requires defining a sense in which the instantiations of sortal properties and of thick properties are realized in micro-structural states of affairs. A fourth notion of realization is needed to allow for the possibility of coincident entities that share a sortal property, e.g., coincident persons.