Online research in philosophy

According to the received view in philosophy of mind, mental states or properties are _realized_ by brain states or properties but are not identical to them. This view is often called _realization_ _physicalism_. Carl Gillett has recently defended a detailed formulation of the realization relation. However, Gillett’s formulation cannot be the relation that realization physicalists have in mind. I argue that Gillett’s “dimensioned” view of realization fails to apply to a textbook case of realization. I also argue Gillett counts as realization some cases that should not count if realization physicalism is to be distinguished from its competitors in the usual ways. I conclude that the relation described by Gillett cannot be realization.

According to the subset account of realization, a property, F, is realized by another property, G, whenever F is individuated by a non-empty proper subset of the causal powers by which G is individuated (and F is not a conjunctive property of which G is a conjunct). This account is especially attractive because it seems both to explain the way in which realized properties are nothing over and above their realizers, and to provide for the causal efficacy of realized properties. It therefore seems to provide a way around the causal exclusion problem. There is reason to doubt, however, that the subset account can achieve both tasks. The problem arises when we look closely at the relation between properties and causal powers, specifically, at the idea that properties confer powers on the things that have them. If realizers are to be ontically prior to what they realize, then we must regard the conferral of powers by properties as a substantive relation of determination. This relation of conferral is at the heart of a kind of exclusion problem, analogous to the familiar causal exclusion problem. I argue that the subset account cannot adequately answer this new exclusion problem, and is for that reason ill-suited to be the backbone of a non-reductive physicalism.

Twenty years ago, Richard Boyd suggested that physicalism could be formulated by appeal to a notion of realization, with no appeal to the identity of the non-physical with the physical. In (Melnyk 2003), I developed this suggestion at length, on the basis of one particular account of realization. I now ask what happens if you try to formulate physicalism on the basis of other accounts of realization, accounts due to LePore and Loewer and to Shoemaker. Having explored two new formulations of physicalism, I conclude that my 2003 formulation remains the most promising.

The realization relation is commonly explicated via, or identified with, the causal role playing relation. However, the realization relation does not formally match the causal role playing relation. While realization is a relation between a base realizer property and a single higher level realized property, I argue that the causal role playing relation as typically defined is a relation between a base property and two higher-level role properties. Advocates of using causal role playing to explicate realization must therefore decide which of the two kinds of role property they identify with realized properties; I argue that neither choice is good, and the fact that one must make a choice is worse. A search for a new way of defining realization is in order.

In this paper I develop a theory of the physical realization of higher-level properties. I argue that physical realization is in an important sense indirect, and that at each level causal relations are crucial to realizing next-level phenomena. My account makes it intelligible how higher-level properties can be realized by wide stretches of physical reality without the inter-level dependence becoming weak, or global; it also explains how both physicalism and non-reductivism can be true.

Realization can be roughly understood as a kind of role-playing, a relationship between a property that plays a role and a property characterized by that role. This rough sketch previously received only moderate elaboration; recently, however, several substantive theories of realization have been proposed. But are there any general constraints on a theory of realization? What is a theory of realization supposed to accomplish? I first argue that a view of realization is viable, in part, to the extent that physical realization under that view explains or accounts for why instances of realized properties are necessitated by how things are physically in a modally strong sense. In this sense, I claim that physical realization should explain physical supervenience. I then call into question two alternative desiderata and raise a challenge for attempts to explicate realization in terms of isomorphism or analogy. Finally, I explain how a causal-functional account of realization, as well as less demanding accounts, can meet the preferred desideratum.

A major objection to the view that the relation of persons to human animals is coincidence rather than identity is that on this view the human animal will share the coincident person's physical properties, and so should (contrary to the view) share its mental properties. But while the same physical predicates are true of the person and the human animal, the difference in the persistence conditions of these entities implies that there will be a difference in the properties ascribed by these predicates, with the result that the physical properties that determine the person's mental states will belong to the person and not to the human animal.

The paper is concerned with how neo-Lockean accounts of personal identity should respond to the challenge of animalist accounts. Neo-Lockean accounts that hold that persons can change bodies via brain transplants or cerebrum transplants are committed to the prima facie counterintuitive denial that a person is an (biologically individuated) animal. This counterintuitiveness can be defused by holding that a person is biological animal (on neo-Lockean views) if the “is” is the “is” of constitution rather than the “is” of identity, and that a person is identical with an animal in a sense of “animal” different from that which requires the persistence conditions of animals to be biological. Another challenge is the “too many minds problem”: if persons and their coincident biological animals share the same physical properties, and mental properties supervene on physical properties, the biological animal will share the mental properties of the person, and so should itself be a person. The response to this invokes a distinction between “thin” properties, which are shared by coincident entities, and “thick” properties which are not so shared. Mental properties, and their physical realizers, are thick, not thin, so are not properties persons share with their bodies or biological animals. The paper rebuts the objection that neo-Lockean accounts cannot explain how persons can have physical properties. To meet a further problem it is argued that the biological properties of persons and those of biological animals are different because of differences in their causal profiles.

Sydney Shoemaker has proposed a new definition of `realization’ and used it to try to explain how mental events can be causes within the framework of a non-reductive physicalism. I argue that it is not actually his notion of realization that is doing the work in his account of mental causation, but rather the assumption that certain physical properties entail mental properties that do not entail them. I also point out how his account relies on certain other controversial assumptions, including analytical filler-functionalism for mental properties, and the assumption that causes must be proportional to their effects. I conclude by pointing out that Shoemaker has provided no explanation of why, on his view, certain physical properties entail mental properties.

According to a prominent line of thought, we can be physicalists, but not reductive physicalists, by holding that mental and other ‘higher-level’ or ‘nonbasic’ properties — properties that are not obviously physical properties — are all physically realized. Spelling this out requires an account of realization, an account of what it is for one property to realize another. And while several accounts of realization have been advanced in recent years,1 my interest here is in the ‘subset view,’ which has often been invoked explicitly in defense of nonreductive physicalist positions.2 The subset view holds that property realization consists in the powers of one property having as a subset the powers of another; ..