Eliminativism and Evolutionary Debunking

Eliminativists sometimes invoke evolutionary debunking arguments against ordinary object beliefs, either to help them establish object skepticism or to soften the appeal of commonsense ontology. I argue that object debunkers face a self-defeat problem: their conclusion undermines the scientific support for one of their premises, because evolutionary biology depends on our object beliefs. Using work on reductionism and multiple realizability from the philosophy of science, I argue that it will not suffice for an eliminativist debunker to simply appeal to some object-free surrogate theory of evolution that results from converting any scientific proposition about some object K into a proposition about simples arranged K-wise. In the process, I examine some hazards peculiar to eliminative reductions of scientific theories, and propose a trilemma for eliminativists who attempt to recoup generality for ontologically sparse reducing theories by appealing to pluralities of simples arranged K-wise. The paper is intended to define and develop the object debunker’s self-defeat problem for further study, and to clarify some of the ways sparse and abundant ontologies interact with scientific theory.

Autonomy

This chapter relates the philosophical concept of multiple realizability to the physics concept of universality. It discusses and responds to Elliott Sober’s defense of reductionism in the face of multiple realizability. Further, it introduces an important explanatory question (labelled AUT). This asks how systems that are heterogeneous at some micro-scale can exhibit the same pattern of behavior at the macro-scale. It is shown that reductionists do not have the resources to provide a successful answer. Two, related, answers are proposed. One involving Renormalization Group arguments, the other invoking the theory of homogenization.

Mechanistic Functionalism

The first three chapters introduced mechanisms, including functional mechanisms—that is, mechanisms that have teleological functions. This chapter introduces a mechanistic version of functionalism. Functionalism is the view that the nature of something is functional. Mechanistic functionalism embeds this claim in the functions of mechanisms and their components. Mechanistic functions are inseparable from the structures that perform them at the relevant level of organization. Weak (mechanistic) functionalism entails multiple realizability; strong (mechanistic) functionalism entails medium independence. Thus, even if medium independence is closely related to computation, (mechanistic) functionalism about cognition does not entail that cognition is computational. In addition, (mechanistic) functionalism entails neither traditional anti-reductionism nor the autonomy of the special sciences.

Mechanisms, Multiple Realizability, and Medium Independence

This chapter provides an account of realization within a mechanistic framework and introduces the notions of variable realizability, multiple realizability, and medium independence. Realization is the relation between a higher-level property and the lower-level properties of which it is an aspect. Variable realizability occurs when the same higher-level property can be realized by different lower-level properties—different lower-level properties share the same aspect. Variable realizability is ubiquitous yet insufficient for multiple realizability proper. Multiple realizability proper occurs when the same higher-level property can be realized by different lower-level properties that constitute different mechanisms for that property at the immediately lower mechanistic level. Medium independence is an even stronger condition than multiple realizability: it occurs when not only is a higher-level property multiply realizable; in addition, the inputs and outputs that define the higher-level property are also multiply realizable. Thus, all that matters to defining a medium-independent higher-level property is the manipulation of certain degrees of freedom. Medium independence entails multiple realizability, which in turn entails variable realizability, but variable realizability does not entail multiple realizability, which in turn does not entail medium independence.

Neurocognitive Mechanisms

This book provides the foundations for a neurocomputational explanation of cognition based on contemporary cognitive neuroscience. An ontologically egalitarian account of composition and realization, according to which all levels are equally real, is defended. Multiple realizability and mechanisms are explicated in light of this ontologically egalitarian framework. A goal-contribution account of teleological functions is defended, and so is a mechanistic version of functionalism. This provides the foundation for a mechanistic account of computation, which in turn clarifies the ways in which the computational theory of cognition is a multilevel mechanistic theory supported by contemporary cognitive neuroscience. The book argues that cognition is computational at least in a generic sense. The computational theory of cognition is defended from standard objections yet a priori arguments for the computational theory of cognition are rebutted. The book contends that the typical vehicles of neural computations are representations and that, contrary to the received view, neural representations are observable and manipulable in the laboratory. The book also contends that neural computations are neither digital nor analog; instead, neural computations are sui generis. The book concludes by investigating the relation between computation and consciousness, suggesting that consciousness may have a functional yet not wholly computational nature.

Peter Browne on the Metaphysics of Knowledge

The central unifying element in the philosophy of Peter Browne (d. 1735) is his theory of analogy. Although Browne's theory was originally developed to deal with some problems about religious language, Browne regards analogy as a general purpose cognitive mechanism whereby we substitute an idea we have to stand for an object of which we, strictly speaking, have no idea. According to Browne, all of our ideas are ideas of sense, and ideas of sense are ideas of material things. Hence we can conceive of spiritual things – including even our own spirit – only by analogy. One interesting application Browne makes of his theory is an account of how concepts such as knowledge can be correctly applied to beings that have no intrinsic properties in common, such as non-human animals, humans, angels, and God. I argue that this is best understood as what, in the contemporary literature, is known as a ‘multiple realizability’ problem and that Browne's solution to this problem has important similarities to functionalist theories in recent philosophy of mind.

Criticism of D.B Volkov’s Teleofunctional Solution to the Problem of Mental Causation

The articles examines the teleofunctional solution to the problem of mental causation, presented by Dmitry Volkov in his recently published book Free Will. An Illusion or an Opportunity. D.B. Volkov proposes solutions to three big metaphysical problems – mental causation, personal identity, and free will. Solving the first problem, Volkov creatively combines the advantages of Dennett’s teleofunctional model and Vasilyev’s local interactionism. Volkov’s teleofunctional model of mental causation seeks to prove the causal relevance of mental properties as non-local higher order properties. In my view, its substantiation is based on three points: (a) critics of the exclusion problem and Kim’s model of mental causation, (b) “Library of first editions” argument, (c) reduction of the causal trajectories argument (CTA 1) by Vasilyev to the counterpart argument (CTA 2) by Volkov. Each of these points faces objections. Kim’s criticism is based on an implicit confusion of two types of reduction – reduction from supervenience and from multiple realizability. The latter type does not threaten Kim’s ideas, but Volkov uses this very type in his criticism. The “Library of first editions” argument does not achieve its goal due to compositional features and because non-local relational properties are a type of external properties that cannot be causally relevant. The reduction of CTA 1 to CTA 2 is unsuccessful since, in the case of this reduction, important features of CTA 1 are lost – these are local mental properties, due to which the influence of non-local physical factors occurs. My main objection is that the concept of causally relevant non-local properties is incompatible with the very concept of cause. The set of causally relevant properties of cause can only be local.

Fodor on multiple realizability and nonreductive physicalism: Why the argument does not work

This paper assesses Fodor’s well-known argument from multiple realizability to nonreductive physicalism. Recent work has brought out that the empirical case for cross-species multiple realizability is weak at best and so we consider whether the argument can be rebooted using a “thin” notion of intra-species multiple realizability, taking individual neural firing patterns to be the realizers of mental events. We agree that there are no prospects for reducing mental events to individual neural firing patterns. But there are more plausible candidates for the neural realizers of mental events out there, namely, global neural properties such as the average firing rates of neural populations, or the local field potential. The problem for Fodor’s argument is that those global neural properties point towards reductive versions of physicalism.