Online research in philosophy

What is the nature of consciousness? How is consciousness related to brain processes? This volume collects thirteen new papers on these topics: twelve by leading and respected philosophers and one by a leading color-vision scientist. All focus on consciousness in the "phenomenal" sense: on what it's like to have an experience. Consciousness has long been regarded as the biggest stumbling block for physicalism, the view that the mind is physical. The controversy has gained focus over the last few decades, and phenomenal knowledge and phenomenal concepts--knowledge of consciousness and the associated concepts--have come to play increasingly prominent roles in this debate. Consider Frank Jackson's famous case of Mary, the super-scientist who learns all the physical information while confined in a black-and-white room. According to Jackson, if physicalism is true, then Mary's physical knowledge should allow her to deduce what it's like to see in color. Yet it seems intuitively clear that she learns something when she leaves the room. But then how can consciousness be physical? Arguably, whether this sort of reasoning is sound depends on how phenomenal concepts and phenomenal knowledge are construed. For example, some argue that the Mary case reveals something about phenomenal concepts but has no implications for the nature of consciousness itself. Are responses along these lines adequate? Or does the problem arise again at the level of phenomenal concepts? The papers in this volume engage with the latest developments in this debate. The authors' perspectives range widely. For example, Daniel Dennett argues that anti-physicalist arguments such as the knowledge argument are simply confused; David Papineau grants that such arguments at least reveal important features of phenomenal concepts; and David Chalmers defends the anti-physicalist arguments, arguing that the "phenomenal concept strategy" cannot succeed.

The knowledge argument is an argument against physicalism that was first formulated by Frank Jackson in 1982. While Jackson no longer endorses it, it is still regarded as one of the most important arguments in the philosophy of mind. Physicalism is the metaphysical thesis that, roughly speaking, everything in this world—including tables, galaxies, cheese cakes, cars, atoms, and even our sensations— are ultimately physical. The knowledge argument attempts to undermine this thesis by appealing to the following simple imaginary scenario: Mary is confined to a black-and-white room, is educated through black-and-white books and through lectures relayed on black-and white television. In this way she learns everything there is to know about the physical nature of the world. She knows all the physical facts about us and our environment, in a wide sense of ‘physical’ which includes everything in completed physics, chemistry, and neurophysiology, and all there is to know about the causal and relational facts consequent upon all this, including of course functional roles. (Jackson 1986, p. 291) The knowledge argument says that if physicalism is true, Mary knows everything in this world. However, it seems obvious that her knowledge is not yet complete. Suppose that..

This paper develops a response to the knowledge argument against physicalism. The response is both austere, in that it does not concede the existence of non-physical information (much less non-physical facts), and natural, in that it acknowledges the alethic character of phenomenal knowledge and learning. I argue that such a response has all the advantages and none of the disadvantages of existing objections to the knowledge argument. Throughout, the goal is to develop a response that is polemically effective in addition to theoretically sound.

According to Frank Jackson’s famous knowledge argument, Mary, a brilliant neuroscientist raised in a black and white room and bestowed with complete physical knowledge, cannot know certain truths about phenomenal experience. This claim about knowledge, in turn, implies that physicalism is false. I argue that the knowledge argument founders on a dilemma. Either (i) Mary cannot know the relevant experiential truths because of trivial obstacles that have no bearing on the truth of physicalism or (ii) once the obstacles have been removed, Mary can know the relevant truths. If we give Mary the epistemological capabilities necessary to draw metaphysical conclusions about physicalism, she will, while trapped in the black and white room, be able to know every truth about phenomenal experience.

According to the knowledge argument, physicalism fails because when physically omniscient Mary first sees red, her gain in phenomenal knowledge involves a gain in factual knowledge. Thus not all facts are physical facts. According to the ability hypothesis, the knowledge argument fails because Mary only acquires abilities to imagine, remember and recognise redness, and not new factual knowledge. I argue that reducing Mary’s new knowledge to abilities does not affect the issue of whether she also learns factually: I show that gaining specific new phenomenal knowledge is required for acquiring abilities of the relevant kind. Phenomenal knowledge being basic to abilities, and not vice versa, it is left an open question whether someone who acquires such abilities also learns something factual. The answer depends on whether the new phenomenal knowledge involved is factual. But this is the same question we wanted to settle when first considering the knowledge argument. The ability hypothesis, therefore, has offered us no dialectical progress with the knowledge argument, and is best forgotten.

Phenomenal knowledge usually comes from experience. But it need not. For example, one could know what it’s like to see red without seeing red—indeed, without having any color experiences. Daniel Dennett (2007) and Pete Mandik (forthcoming) argue that this and related considerations undermine the knowledge argument against physicalism. If they are right, then this is not only a problem for anti‐physicalists. Their argument threatens to undermine any version of phenomenal realism—the view that there are phenomenal properties, or qualia, that are not conceptually reducible to physical or functional properties. I will argue that this threat is illusory. Explaining why will clarify what is and is not at issue in discussions of the knowledge argument and phenomenal realism. This will strengthen the case for physically and functionally irreducible qualia.

Frank Jackson first presented the Knowledge Argument (henceforth KA) in "Epiphenomenal Qualia" 1982). The KA is an argument against physicalism, the doctrine that (very roughly put) everything is physical. The general thrust of the KA is that physicalism errs by misconstruing or denying the existence of the subjective features of experience. Physicalists have given numerous responses, and the debate continues about whether the KA ultimately succeeds in refuting any or all forms of physicalism. Jackson himself has recently.

The knowledge argument aims to refute physicalism, the view that the world is entirely physical. The argument first establishes the existence of facts (or truths or information) about consciousness that are not a priori deducible from the complete physical truth, and then infers the falsity of physicalism from this lack of deducibility. Frank Jackson (1982, 1986) gave the argument its classic formulation. But now he rejects the argument (Jackson 1998b, 2003, chapter 3 of this volume). On his view, it relies on a false conception of sensory experience, which should be replaced with representationalism (also known as intentionalism), the view that phenomenal states are just representational states. And he argues that mental representation is physically explicable.