Daniel Stoljar

Physicalism is the thesis that everything is physical, or as contemporary philosophers sometimes put it, that everything supervenes on, or is necessitated by, the physical. The thesis is usually intended as a metaphysical thesis, parallel to the thesis attributed to the ancient Greek philosopher Thales, that everything is water, or the idealism of the 18th Century philosopher Berkeley, that everything is mental. The general idea is that the nature of the actual world (i.e. the universe and everything in it) conforms to a certain condition, the condition of being physical. Of course, physicalists don't deny that the world might contain many items that at first glance don't seem physical — items of a biological, or psychological, or moral, or social nature. But they insist nevertheless that at the end of the day such items are either physical or supervene on the physical.

Ignorance and Imagination advances a novel way to resolve the central philosophical problem about the mind: how it is that consciousness or experience fits into a larger naturalistic picture of the world. The correct response to the problem, Stoljar argues, is not to posit a realm of experience distinct from the physical, nor to deny the reality of phenomenal experience, nor even to rethink our understanding of consciousness and the language we use to talk about it. Instead, we should view the problem itself as a consequence of our ignorance of the relevant physical facts, Stoljar shows that this change of orientation is well motivated historically, empirically, and philosophically, and that it has none of the side effects it is sometimes thought to have. The result is a philosophical perspective on the mind that has a number of far-reaching consequences: for consciousness studies, for our place in nature, and for the way we think about the relationship between philosophy and science.

Many philosophers of mind are concerned to defend the thesis called physicalism ; many others are concerned to refute it. Nevertheless, there is no generally agreed on idea of what physicalism is, and why it should matter whether the mental is physical. My thesis consists of four essays whose concern is with what physicalism is in its most plausible version, and what the importance of the thesis might be for the philosophy of mind. ;I begin with the question of whether it is possible to hold physicalism in a nonreductive form. Nonreductive physicalism is a doctrine that divides into two parts. The first part--the physicalist part--is that mental properties and facts supervene on physical properties and facts. The second part--the nonreductivist part--is that this supervenience thesis does not imply that mental properties and facts are reduced to physical properties and facts. In chapter one, I argue that, when properly understood, these two claims are not cotenable. ;In chapter two, I consider a different way of developing nonreductive physicalism. ;My discussion of nonreductive physicalism has a conditional conclusion: nonreductive physicalism reduces to reductive physicalism, and thus, if one wants to be a physicalist, one must be a reductive physicalist. Accordingly, in chapter three, I turn to reductive physicalism: the thesis that mental properties simply are physical properties. ;In the final chapter, I assess the reasons for believing physicalism. Physicalists have a number of different reasons for believing their doctrine, but perhaps the most widespread is the idea that one should believe physicalism because to renounce it would be, as Schiffer has put it, "to renounce the scruples of the natural scientist". I reply that this is a mistake born from missing an ambiguity in the word 'physical'. In one sense, 'physical' applies to a property or fact which the empirical sciences are in the best position to describe. In another sense, 'physical' applies to a property or fact which a certain sub-class of the empirical sciences are in the best position to describe, namely, the subclass which includes contemporary physics, chemistry, biology and neuroscience. What is at issue in the philosophy of mind is physicalism where 'physical' has this second stricter sense. However, under that interpretation, to renounce physicalism is not, I argue, to renounce the scruples of the natural scientist. Moreover, under that interpretation, there is no strong pressure to revise our conception of what a mental property is in order to ensure the truth of physicalism.

The topic of introspection stands at the interface between questions in epistemology about the nature of self-knowledge and questions in the philosophy of mind about the nature of consciousness. What is the nature of introspection such that it provides us with a distinctive way of knowing about our own conscious mental states? And what is the nature of consciousness such that we can know about our own conscious mental states by introspection? How should we understand the relationship between consciousness and introspective self-knowledge? Should we explain consciousness in terms of introspective self-knowledge or vice versa? Until recently, questions in epistemology and the philosophy of mind were pursued largely in isolation from one another. This volume aims to integrate these two lines of research by bringing together fourteen new essays and one reprinted essay on the relationship between introspection, self-knowledge, and consciousness.

This paper defends a novel view of ‘what it is like’-sentences, according to which they attribute certain sorts of relations—I call them ‘affective relations’—that hold between events and individuals. The paper argues in detail for the superiority of this proposal over other views that are prevalent in the literature. The paper further argues that the proposal makes better sense than the alternatives of the widespread use of Nagel’s definition of conscious states and that it also shows the mistakes in two prominent suggestions about the definition when properly understood: first, that it is empty and uninformative, and second, that it leads directly to a substantial claim in the theory of consciousness, namely that an individual is in a conscious state only if the individual is aware of their being in that state.

Consciousness is extremely familiar yet it is at the limits—beyond the limits, some would say—of what one can sensibly talk about or explain. Perhaps this is the reason its study has drawn contributions from many fields including psychology, neuroscience, philosophy, anthropology, cultural and literary theory, artificial intelligence, physics, and others. The focus of this entry is on: the varieties of consciousness, different problems that have been raised about these varieties, and prospects for progress on these problems.

What is the connection between being in a conscious mental state and believing that you yourself are currently in that state? On the one hand, it is natural to think that this connection is, or involves, a necessary connection of some sort. On the other hand, it is hard to know what the nature of this necessary connection is. For there are plausible arguments according to which this connection is not metaphysically necessary, not rationally necessary, and not merely naturally necessary. If these arguments are correct, and if these options are exhaustive, while there is a necessary connection between a conscious state and the belief that you are in it, there is apparently no necessary connection it could be! This paper sets out this problem—the necessary connection problem, I will call it—and defends and explores a novel proposal about how to solve it.

This chapter begins with a putative puzzle between non-reductive physicalism according to which psychological properties are distinct from, yet metaphysically necessitated by, physical properties, and Hume's dictum according to which there are no necessary connections between distinct existences. However, the puzzle dissolves once care is taken to distinguish between distinct kinds of distinction: numerical distinctness, mereological distinctness, and what the chapter calls ‘weak modal distinctness’ and ‘strong modal distinctness’. For each of these notions, it turns out that either it makes no sense according to non-reductive physicalism or else it is unclear whether Hume's dictum is true. The chapter then deploys these distinctions to argue first that unlike the dualist, the non-reductive physicalist can reject the exclusion principle in the causal exclusion argument, and second that emergentism can be distinguished from non-reductive physicalism.

This article explores two consequences of intentionalism. My first line of argument focuses on the impact of intentionalism on the 'hard problem' of phenomenal character. If intentionalism is true, the phenomenal supervenes on the intentional. Furthermore, if physicalism about the intentional is also true, the intentional supervenes on the physical. Therefore, if intentionalism and physicalism are both true, then, by transitivity of supervenience, physicalism about the phenomenal is true. I argue that this transitivity argument is not persuasive, because on any interpretation of its central terms, at least one of its premises is as controversial as its conclusion already is. My second line of argument is about the consequences of intentionalism for the error theory of color perception. I suggest that if intentionalism is true, projectivism must be true also, because under this condition there is no single concept of color that can be used for the qualification of objects as well as for the characterization of experiences.

It is sometimes suggested that expressivism in meta-ethics is to be criticized on grounds which do not themselves concern meta-ethics in particular, but which rather concern philosophy of language more generally. Frank Jackson and Philip Pettit (1998; see also Jackson and Pettit 1999, and Jackson 2001) have recently advanced a novel version of such an argument. They begin by noting that expressivism in its central form makes two claims—that ethical sentences are not truth evaluable, and that to assert an ethical sentence is to express one’s desires or feelings rather than to report a fact. They then argue that, given some plausible premises in the philosophy of language emanating mainly from Locke, the two central claims of expressivism are contradictory: when combined with the plausible premises, they say, the second claim refutes the first. The purpose of this paper is to formulate Jackson and Pettit’s Lockean argument, and to suggest that it fails