Sven Walter

This paper examines Jaegwon Kim's Supervenience Argument (SA) against nonreductive physicalism, concentrating on Kim's response to two of the most important objections against the SA: First, the Overdetermination Argument, according to which Kim has no convincing argument against the possibility that mental causation might be a case of genuine or systematic overdetermination; second, the Generalization Argument, according to which the SA would entail that causation at any level gives way to causation at the next lower level, thereby leading to an untenable all-encompassing epiphenomenalism. It is argued that as of yet, Kim has failed to develop a coherent overall position, since various moves he makes in response to these criticisms are strangely at odds with other parts of his philosophical position.

In a recent contribution to this journal, Andrew Fenton and Sheri Alpert have argued that the so-called “extended mind hypothesis” allows us to understand why Brain Computer Interfaces (BCIs) have the potential to change the self of patients suffering from Locked-in syndrome (LIS) by extending their minds beyond their bodies. I deny that this can shed any light on the theoretical, or philosophical, underpinnings of BCIs as a tool for enabling communication with, or bodily action by, patients with LIS: BCIs are not a case of cognitive extension. I argue that Fenton and Alpert’s claim to the contrary is the result of a widespread confusion about some related, but significantly different, approaches to cognition that all fall under the heading of “situated cognition.” I first provide a short taxonomy of various situated approaches to cognition, highlighting (some of) their important commonalities and differences, which should dissolve some of the confusions surrounding them. Then I show why the extended mind hypothesis is unsuitable as a model of BCI enhancements of LIS patients’ capacity to interact with their surroundings, and I argue that the situated approach with obvious bearings on the sort of questions that were driving Fenton and Alpert is not the idea that cognition is extended , but the idea that cognition is enacted.

Mental causation, our mind's ability to causally affect the course of the world, is part and parcel of our ‘manifest image’ of the world. That there is mental causation is denied by virtually no one. How there can be such a thing as mental causation, however, is far from obvious. In recent years, discussions about the problem of mental causation have focused on Jaegwon Kim's so-called Causal Exclusion Argument, according to which mental events are ‘screened off’ or ‘preempted’ by physical events unless mental causation is a genuine case of overdetermination or mental properties are straightforwardly reducible to physical properties.

Frank Jackson and Philip Pettit have defended a non-reductive account of causal relevance known as the ‘program explanation account’. Allegedly, irreducible mental properties can be causally relevant in virtue of figuring in non-redundant program explanations which convey information not conveyed by explanations in terms of the physical properties that actually do the ‘causal work’. I argue that none of the possible ways to spell out the intuitively plausible idea of a program explanation serves its purpose, viz., defends non-reductive physicalism against Jaegwon Kim’s Causal Exclusion Argument according to which non-reductive physicalism is committed to epiphenomenalism because irreducible mental properties are ‘screened off’ from causal relevance by their physical realizers. Jackson and Pettit’s most promising explication of a program explanation appeals to the idea of invariance of effect under variation of realization, but I show that invariance of effect under variation of realization is neither necessary nor sufficient for causal relevance.