Online research in philosophy

In this paper I begin to develop an account of the acquaintance that each of us has with our own conscious states and processes. The account is a speculative proposal about human mental architecture and specifically about the nature of the concepts via which we think in first personish ways about our qualia. In a certain sense my account is neutral between physicalist and dualist accounts of consciousness. As will be clear, a dualist could adopt the account I will offer while maintaining that qualia themselves are non-physical properties. In this case the non-physical nature of qualia may play no role in accounting for the features of acquaintance. But although the account could be used by a dualist, its existence provides support for physicalism.

Although the capacity to discriminate between different qualia is typically admitted to have a definition in terms of functional role, the qualia thereby related are thought to elude functional definition. In this paper I argue that these views are inconsistent. Given a functional model of discrimination, one can construct from it a definition of qualia. The problem is similar in many ways to Goodman's definition of qualia in terms of 'matching', and I argue that many of his findings survive reinterpretation into a physicalistic basis which employs 'indiscriminability' as its primitive term. I show how one can identify the critical properties to which discrimination capacities are sensitive, and then identify their order. A problem arises concerning the different ways in which qualitatively distinct experiences can differ (hue, shape, and so on). Physicalist accounts have often been accused of relying in a circular fashion on some antecedent understanding of phenomenal properties in order to specify those differences. This account avoids such an accusation: ordering of critical properties is determined by the dimensionality of discriminations, and the latter is given by the structure of the discrimination pair lists. Once a topology of quality is constructed, qualia names can be defined by their relative location within the order. In the conclusion I argue that psychophysics employs physicalist techniques to define a topology of quality, and that it can provide what Thomas Nagel calls an "objective phenomenology.".

Over the past decade or so, David Papineau has given an account of the content and motivation of a physicalist conception of the world with more thoroughness and argumentative defence than many physicalists have thought necessary. In doing this, he has substantially advanced the debate on physicalism, and physicalists and non-physicalists alike should be grateful to him.1 At the heart of Papineau’s defence of physicalism in his recent book (2002) is his theory of phenomenal concepts. Like many physicalists, Papineau diagnoses the apparent threats to physicalism posed by the phenomena of consciousness by locating the source of anti-physicalist intuitions in features of our thinking rather than in non-physical features of reality. But what is new in Thinking About Consciousness is his detailed account of which features of our thinking it is that generate these supposedly confused anti-physicalist arguments. Hence the bulk of the book is an attempt to show that the most famous ‘consciousness-based’ anti-physicalist arguments—the knowledge argument, the zombie argument and the explanatory gap argument—rest on a mistaken understanding of certain kinds of concepts: phenomenal concepts. I agree with Papineau that physicalism (properly understood) should not be troubled by the knowledge argument and the explanatory gap argument, and that some other anti-physicalist arguments seem to move from assumptions about ways of thinking to conclusions about reality. But I doubt whether his theory of phenomenal concepts can help his defence of physicalism and his diagnosis of the errors of dualism. My reason for saying this is that I do not think there are any such concepts. In saying this I do not mean to deny that there is a useful distinction to be made between scientific concepts, the mastery of which requires knowledge of a certain amount of theory, and concepts which are acquired on the basis of experience, which can be called ‘phenomenal’ concepts.

In this paper I begin by explaining the concept of supervenience. I then describe the problem of qualia and explain why qualia are a problem for physicalist theories of the mind. Next, I outline the zombie argument and explain Chalmers' attempt to use it as an argument for the conclusion that qualia do not logically supervene on the physical. My goal is to show that the supposed conceivability of zombies does not offer any serious refutation of physicalist theories of the mind.

Qualia and Physicalism. It is assumed that the following three relations exhaust the possibilities for a physicalist account of qualia: 1. determination, 2. identity, 3. realization. The first relation is immediately rejected because it does not exclude property dualism. The second faces the problem that it is probably impossible to discriminate empirically between the identity thesis and the epiphenomenalist position. The third cannot handle qualia adequately, for qualia are not functional properties and the realization relation is only plausible as a relation between physical realizers and functional properties. Finally, if one attempts to replace multiple realization by multiple identities it is shown that the notion of multiple property identities is unintelligible. The upshot is that if these three relations exhaust the possibilities of a physicalist construal of qualia then physicalism is wrong.

I argue that the knowledge argument is best understood as an argument for the existence of non-physical properties of material objects, or colours. I suggest that the knowledge argument is standardly presented as an argument for the existence of qualia because it is implicitly assumed that physics “tell us” that what it is like to perceive colour is determined, not by properties of material objects, but by properties of perceiving subjects; hence any gaps in Mary’s knowledge must be gaps in her knowledge about perceiving subjects. If nothing else, this physicalist assumption is odd given that the knowledge argument is supposed to be an argument against physicalism. Using the knowledge argument as an argument for the existence of non-physical colours is consistent with the transparency of perceptual experience. Moreover, rejecting the physicalist assumption behind the orthodox interpretation of the knowledge argument undermines the motivation for thinking of non-physical colours as epiphenomenal.

Frank Jackson's knowledge argument against physicalism has caused an extensive debate. In this paper, I sketch and examine a new argument against Jackson's view, an argument which appears to retain more of physicalism than other replies to Jackson. this argument draws strength from a causal theory of knowledge, and hold that there is no knowledge of epiphenomenal qualia, hence that Jackson's main conclusions from the thought experiment are incorrect. There are still problems with this argument, however, so the question remains how much of the mental that can be accounted for in physicalist terms.

The Knowledge Argument is misconstructed. Knowing that it is ‘just obvious’ that Mary will learn something new on leaving her black and white room, we nevertheless assume she can acquire a complete knowledge of the physical inside it – thereby predetermining the outcome of the thought experiment in favour of a refutation of physicalism. If we reformulate the argument to leave the question of what she can learn in the room open, it becomes clear, not only that physicalism can survive the Knowledge Argument, but also that there is only one perspective on the relationship between qualia and the physical that will permit it to do so. If physicalism is true, this perspective must be the correct view of the qualia-physical relationship – the solution to the mind-body problem, a conclusion supported by its ability to resolve a number of associated difficulties, including Kripke’s problem for proposed identities and Chalmers’ Hard Problem.

A physicalist view of qualia labelled non-eliminative reductionism is outlined. If it is true, qualia and physicalism can co-exist without difficulty. First, qualia present no particular problem for reductionist physicalism - they are entirely physical, can be studied and explained using the standard scientific approach, and present no problem any harder than any other scientists face. Second, reductionist physicalism presents no particular problem for qualia – they can be encompassed within an entirely physicalist position without any necessity, either to reduce them to non-existence, or to treat them as new fundamental properties. It is suggested that the position also has sufficient explanatory power to successfully deal with the 'why like anything – why does experience exist at all' question and to counter both Chalmers' Conceivability Argument and Jackson's Knowledge Argument.

Frank Jackson’s knowledge argument (KA) aims to prove, by means of a thought experiment concerning the hypothetical scientist Mary, that conscious experiences have non-physical properties, called qualia. Mary has complete scientific knowledge of colours and colour vision without having had any colour experience. The central intuition in the KA is that, by seeing colours, Mary will learn what it is like to have colour experiences. Therefore, her scientific knowledge is incomplete, and conscious experiences have qualia. In this paper I consider an objection to the KA raised by Daniel Dennett. He maintains that the KA is vitiated by Jackson’s account of Mary’s scientific knowledge. While endorsing this criticism, I will defend the plausibility and relevance of the type of strategy involved in the KA by offering an account of Mary’s scientific knowledge. This account involves formulating a reasonable and not immediately false version of the physicalist thesis with regard to colour experiences. Whether this version of the KA is successful against this type of physicalism is not investigated here.