Online research in philosophy

Libet's experiments, supported by a strict one-to-one identity thesis between brain events and mental events, have prompted the conclusion that physical events precede the mental events to which they correspond. We examine this claim and conclude that it is suspect for several reasons. First, there is a dual assumption that an intention is the kind of thing that causes an action and that can be accurately introspected. Second, there is a real problem with the method of timing the mental events concerned given that Libet himself has found the reports of subjects to be unreliable in this regard. Third, there is a suspect assumption that there are such things as timable and locatable mental and brain events accompanying and causing human behaviour. For all these reasons we reject the claim that physical events are prior to and explain mental events.

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.

The paper argues that mental causation can be explained from the sufficiency of counterfactual dependence for causation together with relatively weak assumptions about the metaphysics of mind. If a physical event counterfactually depends on an earlier physical event, it also counterfactually depends on, and hence is caused by, a mental event that correlates with (or supervenes on) this earlier physical event, provided that this correlation (or supervenience) is sufficiently modally robust. This account of mental causation is consistent with the overdetermination of physical events by mental events and other physical events, but does not entail it.

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.

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.

This paper is about the causal exclusion argument against non-reductive physicalism. Many philosophers think that this argument poses a serious problem for non-reductive theories of the mind — some think that it is decisive against them. In the first part I will outline non-reductive physicalism and the exclusion argument. Then I will distinguish between three versions of the argument that address three different versions of non-reductive physicalism. According to the first, the relation between mental and physical events is token-identity. According to the second, mental events are distinct from physical events, but the latter metaphysically include and determine the former. And on the third version, mental and physical events are entirely distinct. I will argue that the causal exclusion argument is not decisive against non-reductive physicalism in any of the three versions. According to non-reductive physicalism, mental events are dependent on physical events. Causal exclusion and overdetermination, however, requires distinct and independent causes. I will argue that the burden of proof lies with the opponents of non-reductive physicalism, who have to explain how metaphysically dependent events can possibly overdetermine an effect or exclude each other from being causally efficacious.

Given some reasonable assumptions concerning the nature of mental causation, non-reductive physicalism faces the following dilemma. If mental events cause physical events, they merely overdetermine their effects (given the causal closure of the physical). If mental events cause only other mental events, they do not make the kind of difference we want them to. This dilemma can be avoided if we drop the dichotomy between physical and mental events. Mental events make a real difference if they cause actions. But actions are neither mental nor physical events. They are realized by physical events, but they are not type-identical with them. This gives us non-reductive physicalism without downward causation. The tenability of this view has been questioned. Jaegwon Kim, in particular, has argued that non-reductive physicalism is committed to downward causation. Appealing to the nature of actions, I will argue that this commitment can be avoided.

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.