Online research in philosophy

A typical thesis of contemporary materialism holds that mental properties and events supervene on, without being reducible to, physical properties and events. Many philosophers have grown skeptical about the causal efficacy of irreducibly supervenient properties, however, and one of the main reasons is an assumption about causation which Jaegwon Kim calls the causal exclusion principle. I argue here that this principle runs afoul of cases of genuine causal overdetermination.Many would argue that causal overdetermination is impossible anyway, but a careful analysis of these arguments shows them to be misguided. Finally, I examine the reasons given in support of the causal exclusion principle, and I conclude that it is plausible if, and probably only if, a certain view of the nature of causation turns out to be correct. Since that view of causation is unacceptable to nonreductivists on other grounds, however, it turns out that exclusion-based arguments essentially beg the question.

Physicalists motivate their position by posing a problem for the opposition: given the causal completeness of physics and the impact of the mental (or, more broadly, the seemingly nonphysical) on the physical, antiphysicalism implies that causal overdetermination is rampant. This argument is, however, equivocal in its use of 'physical'. As Scott Sturgeon has recently argued, if 'physical' means that which is the object of physical theory, completeness is plausible, but the further claim that the mental has a causal impact on the physical is no longer so evident. In this paper I assess the damage due to the ambiguity of 'physical' and provide a repair to the overdetermination strategy.

According to an increasing number of authors, the best, if not the only, argument in favour of physicalism is the so-called 'overdetermination argument'. This argument, if sound, establishes that all the entities that enter into causal interactions with the physical world are physical. One key premise in the overdetermination argument is the principle of the causal closure of the physical world, said to be supported by contemporary physics. In this paper, I examine various ways in which physics may support the principle, either as a methodological guide or as depending on some other laws and principles of physics.

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.

Defenders of the subset view of realization have claimed that we can resolve well-known worries about mental-physical causal overdetermination by holding that mental properties are subset realized by physical properties, that instances of subset realized properties are parts of physical realizers, and that part-whole overdetermination is unproblematic. I challenge the claim that the overdetermination generated by the subset view can be legitimated by appealing to more mundane part-whole overdetermination. I conclude that the subset view does not provide a unique solution to overdetermination worries.

In trying to establish the view that there are no non-living macrophysical objects, Trenton Merricks has produced an influential argument—the Overdetermination Argument—against the causal efficacy of composite objects. A serious problem for the Overdetermination Argument is the ambiguity in the notion of overdetermination that is being employed, which is due to the fact that Merricks does not provide any theory of causation to support his claims. Once we adopt a plausible theory of causation, viz. interventionism, problems with the Overdetermination will become evident. After laying out the Overdetermination Argument and examining one extant objection to it, I will explicate the relevant aspects of an interventionist theory of causation and provide a characterization of overdetermination that follows from such an account. From this, I will argue that the Causal Principle that undergirds the Overdetermination Argument is false and hence the argument is invalid; and I claim that the only other available characterization of overdetermination would render a key premise in the argument false. Thus, the Overdetermination Argument fails to provide us with any reason to deny the causal efficacy of macrophysical objects, and therefore provides no reason to doubt their existence.

Causal overdetermination worries arise in a number of domains, but most notably in the philosophy of mind. ln discussions of such worries, alleged examples of causal overdetermination are uniformly viewed as primajzcie 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.

The exclusion problem is held to show that mental and physical events are identical by claiming that the denial of this identity is incompatible with the causal completeness of physics and the occurrence of mental causation. The problem relies for its motivation on the claim that overdetermination of physical effects by mental and physical causes is objectionable for a variety of reasons. In this paper, I consider four different definitions of ?overdetermination? and argue that, on each, overdetermination in all cases of mental causation either does not occur or is unobjectionable, even when mental and physical events are non-identical. I therefore conclude that the exclusion problem cannot be used as a reason to accept that mental and physical events are identical unless some other definition of ?overdetermination? is provided.