Interlevel causation from an interventionist point of view

Subtitle:solving problems in philosophy of mind and in philosophy of science

Interlevel causation, broadly defined as the causal infuence of an entity at one level on an entity at another level, is regularly rejected from a philosophical perspective. This rejection seems to conflict with both everyday experience and scientfic practice in the special sciences. Nowhere is this made clearer than in the context of mental causation, where the denial of downward causation has led to the proliferation of epiphenomenalist conclusions regarding the causal efficaciousness of the mental. In other words, mental events are said to have no causal influence on other mental events or on physical ones. It is my hypothesis in this thesis that the problem of mental causation, and other distinct but related problems, may be resolved by recasting the interlevel relations involved in these discussions as bidirectionally causal from an interventionist perspective. I focus on three such relations in this thesis: supervenience, emergence and constitutive relevance. This hypothesis was tested over the course of five central chapters. Chapter 2 provides a concise description of Woodward's interventionist theory. This does not just include the central principles underlying his account of causation, but also makes a case for its application to the problem of interlevel causation. The argument here is twofold. First, interventionism is already widely applied in the discussions surrounding these interlevel relations, most notably in the debate surrounding the interventionist exclusion argument with regards to mental causation and the mutual manipulability approach to constitutive relevance relations in mechanisms. Second, interventionism draws heavily from methodological considerations in social scientific and biomedical contexts, and as such, is uniquely situated to help overcome the apparent gap between philosophical theory and scientifc practice. Chapter 3 deals with a preliminary problem that arises from the bidirectionally causal approach suggested by my hypothesis. Such bidirectional causation is a form of cyclic causality. Even though such cyclic causality is typically assumed to be amenable to an interventionist reading, I illustrate how interventionist treatments of certain cyclic causal graphs run into acute problems. I subsequently show that through an appropriate modifcation of Woodward's conditions for an intervention variable this gap in interventionist theory may be remedied. Chapter 4 focuses on the supervenience relation. This relation often plays a crucial role in causal exclusion arguments. I zoom in on two prominent arguments of this kind, and the discussions in which they figure. The first of these is the oft-debated causal exclusion problem posited by Jaegwon Kim, which is commonly taken to lead to a rejection of mental causation. This conclusion has been criticized by those who conceive of causation in interventionist terms. I evaluate the specific arguments supporting this move, and show that they fail in at least one respect, namely countering the systematic overdetermination issue, an important component of Kim's exclusion problem. Moreover, this interventionist defense of mental causation has itself been determined to lead to its own version of the causal exclusion problem. This second exclusion argument, designated the interventionist causal exclusion problem, has led to an all new debate, and has resulted in Woodward proposing a modification of his interventionist account. I show that his modification again fails in one important respect, namely with regards to the so termed issue of fat-handedness. I subsequently introduce a novel approach to the supervenience relation, which casts it as a bidirectionally causal relation, supported by a further modification of the interventionist account, which does not fall prey to the issues of systematic overdetermination and fat-handedness, and safeguards mental properties from causal epiphenomenalism. The novel causal approach to supervenience shares many features with a parallel discussion in the emergence literature centered on diachronic emergence. Chapter 5 focuses on this new wave of diachronic emergence relations, which are similarly conceived of as causal to counter the supposed epiphenomenalism of mental phenomena. One common feature of these diachronic emergence accounts is that they explicitly dismiss the supervenience relation, even though the relation between emergents and their base is regularly expressed using supervenience. Different arguments for this dismissal are examined, the most notable of which concern the supposed inability of the supervenience relation to obtain in a diachronic context, the necessity of positing a causal interlevel relation, and the supposed need for a mereological conception of supervenience in conjunction with emergence. I argue that for the most part these reasons are resolved by the bidirectionally causal account of supervenience proposed in the preceding chapter, and that the remainder arise from a set of mistaken assumptions concerning supervenience. I subsequently introduce a new working definition for a diachronic emergence relation, which reformulates it as a distinct species of supervenient emergence within the context of the mind-body debate. The final application of the central hypothesis (chapter 6) revolves around the interlevel relation of constitutive relevance, as it is conceived of in the mechanistic literature. Constitutive relevance relations are explicitly demarcated from causal relations in this literature. However, such a non-causal conception seems to engender a tension with frequent claims of interlevel causation in the scientific literature on mechanisms. An additional issue concerns the fact that the constitutive relevance relation is modeled after Woodward's interventionist account of causation, even though a causal interpretation is excluded. I show that the three principal reasons for this exclusion: the logical independence of the relata, the supposed symmetry of the constitution relation, and its assumed synchronicity, are insufficient and may largely be resolved by the recognition of an inherently temporal dimension in the wet and messy psychological and (neuro)biological contexts in which the constitutive relevance relation in question figures. I consider two case studies, in this respect, to show that such a temporality is important to the scientific analysis of such cases. I subsequently show that this temporal dimension is increasingly recognized in the literature, but that the various proposed solutions seem to mainly add alternative causal interlevel relations instead of arguing on behalf of a causal constitutive relevance relation. I therefore propose a definition for such a bidirectionally causal relation that, I contend, emerges as the best fit in the psychological and (neuro)biological contexts in which the constitutive relevance relation figures. Having tested my hypothesis, I conclude that interlevel causation in these discussions is licensed by a modified interventionist treatment in the right contexts. Approaching these interlevel relations as causal then serves to resolve a number of issues, ranging from the safeguarding of mental causation to the easing of tensions between philosophy and science.

Publication year:2021

Keywords:Doctoral thesis

Accessibility:Open