Abstract: According to Garrett, Chalmers’ zombie argument faces a dilemma:

_Horn 1._ If causal essentialism is true (i.e., if Hume’s thesis is false), then the zombie
world is metaphysically impossible.

Garrett’s argument for this claim can be stated as follows

Abstract: Many philosophers accept the conceivability of zombies: creatures that lack consciousness but are physically and functionally identical to conscious human beings. Many also believe that the conceivability of zombies supports their metaphysical possibility. And most agree that if zombies are metaphysically possible, then physicalism is false. So, the claim that zombies are conceivable may have considerable significance.¹

Abstract: The spokesperson in the Pentagon press room announces the availability of a breakthrough new technology. She says it is the first brain-implantable product of a larger project for developing cybernetic organisms (cyborgs) with new and enhanced sensory capabilities that will also have civilian uses. On the screen we see a device fitted on the forehead of a cyborg that appears to have hardwired connections to the brain on several points on the skull. The spokesperson calls the device “voluvisor.” According to the briefing, the voluvisor provides sensory information about the 3-dimensional volumetric structure of one’s field of voluvision, which is a sensory field roughly coinciding with the width and height of the visual field of a normal adult human but with only 30 to 50 yards of depth sensitivity depending on the volumetric conditions. The voluvisor uses a combination of various types of advanced sonar and short range radar technologies as well as passive detectors for multiple portions of the electromagnetic spectrum, and is fully integrated to the user’s cognitive and sensory motor systems through brain implants for connectivity. In other words, it does not piggyback on the genetically traditional sensory organs and systems of the brain: it provides an independent sensory modality with its own systems of neural networks set up in ways similar to the standard sensory neural networks of the natural brain. Roughly, what the voluvisor does is to provide information for any two discriminable points (atomic volumes) in one’s 3D voluvisual field whether or not they are filled with the same or similar “matter” according to a fixed multidimensional similarity matrix — without giving any (extractable) information about what, if any, the filling material is. It is, basically, a multidimensional tomographic device. Furthermore, it does this in real time preserving the egocentric 3D coordinates of the field, in a way similar to standard vision that gives us surface information of visible objects in real time..

Abstract: It is widely suspected that arguments from conceivability, at least in some of their more notorious instances, are unsound. However, the reasons for the failure of conceivability arguments are less well agreed upon, and it remains unclear how to distinguish between sound and unsound instances of the form. In this paper I provide an analysis of the form of arguments from conceivability, and use this analysis to diagnose a systematic weakness in the argument form which reveals all its instances to be, roughly, either uninformative or unsound. I illustrate this conclusion through a consideration of David Chalmers’ modal argument against physicalism

Abstract:   Christopher Hill and Joseph Levine have argued that the conceivabilitiesinvolved in anti-materialist arguments are defeated as evidence ofpossibility. Their strategy assumes the following principle: theconceivability of a state of affairs S constitutes evidence for thepossibility of S only if the possibility of S is the bestexplanation of the conceivability of S. So if there is a betterexplanation of the conceivability of S than its possibility, then theconceivability of S is thereby defeated as evidence of possibility. Hilland Levine proceed to offer alternative explanations of theseconceivabilities, concluding that these conceivabilities are therebydefeated as evidence. However, this strategy fails because theirexplanations generalize to all conceivability judgments concerningphenomenal states. Consequently, one could defend absolutely any theoryof phenomenal states against conceivability arguments in just this way.This result conflicts with too many of our common sense beliefs aboutthe evidential value of conceivability with respect to phenomenalstates. The general moral is that the application of such principles ofexplanatory defeat is neither simple nor straightforward

Abstract: The paper begins with a clarification of the notions of intuition (and, in particular, modal intuition), modal error, conceivability, metaphysical possibility, and epistemic possibility. It is argued that two-dimensionalism is the wrong framework for modal epistemology and that a certain nonreductionist approach to the theory of concepts and propositions is required instead. Finally, there is an examination of moderate rationalism’s impact on modal arguments in the philosophy of mind -- for example, Yablo's disembodiment argument and Chalmers's zombie argument. A less vulnerable style of modal argument is defended, which nevertheless wins the same anti-materialist conclusions sought by these other arguments

Abstract: Scientific essentialism is the view that some necessities (e.g., water = H2O) can be known only with the aid of empirical science. The thesis of the paper is that scientific essentialism does not extend to the central questions of philosophy and that these questions can be answered a priori. The argument is that the evidence required for the defense of scientific essentialism (e.g., twin earth intuitions) is reliable only if the intuitions required by philosophy to answer its central questions is also reliable. Included is an outline of a modal reliabilist theory of basic evidence and a concept-possession account of the reliability of a priori intuition

Abstract: Case 1: Perhaps the phenomenal facts—facts about what it’s like to see red, or to taste freshly made pesto—do not supervene with metaphysical necessity on the physical facts and physical laws. This might be because the connections between the physical and the phenomenal are entirely unprincipled. Alternatively, it might be because whatever psychophysical laws do govern those connections are contingent. Either way, the claim is that there are metaphysically possible worlds that are just like the actual world in terms of what physical laws hold, and in terms of the distribution of physical properties, but which are phenomenally different from the actual world. In some such worlds, different phenomenal facts obtain. In other such worlds, no phenomenal properties are instantiated at all. Call the latter sort of world a ‘phenomenal zombie world’, or, for short, just a ‘zombie world’

Abstract: I argue that property dualism is not supported by the purported logical possibility of qualitative zombies. Chalmers’s analysis of the logical supervenience of ordinary macroscopic facts on microphysical facts fails to account properly for causal properties. His arguments rely too heavily on kinematic facts and thereby obscure the dynamical facts at the macroscopic and microscopic levels. A proper analysis of the relation between causal and dynamical properties at different levels reveals that we can only imagine qualitative zombies if we beg the question against qualia being physical

Abstract: John Perry's book Knowledge, Possibility, and Consciousness is a lucid and engaging defense of a physicalist view of consciousness against various anti-physicalist arguments. In what follows, I will address Perry's responses to the three main anti-physicalist arguments he discusses: the zombie argument (focusing on imagination), the knowledge argument (focusing on indexicals), and the modal argument (focusing on intensions)

Abstract: What follows are compressed versions of three lectures on the subject of "Mind and Modality", given at Princeton University the week of October 12-16, 1998. The first two form a series; the third stands alone to some extent. All are philosophically technical, and probably of interest mainly to philosophers. I hope that they make sense, at least to those familiar with my book

_The Conscious Mind_ .

Lecture 1 recapitulates some of the material in the book in a somewhat different form, and adds some further material on conditionals and on Kripke. Note that section has a more or less definitive formalization of the anti-materialist argument from the book (lots of people have asked for this). Lecture 2 pushes deeper into the heart of modality, further investigating the conceivability/possibility relationship and the epistemology of modality (with some material on the scrutability of truth in general), and arguing for a sort of modal rationalism. Lecture 3 gives an analysis of the content of beliefs about experiences, and applies this to a number of epistemological issues, including incorrigibility and the dialectic on "The Myth of the Given"

Abstract: In Section 5 of his interesting article, Goldman suggests that the consideration of imaginary cases can be valuable in the analysis of our psychological concepts. In particular, he argues that we can imagine a system that is isomorphic to us under any functional description, but which lacks qualitative mental states, such as pains and color sensations. Whether or not such a being is empirically possible, it certainly seems to be logically possible, or conceptually coherent. Goldman argues from this possibility to the conclusion that our concepts of qualitative mental states cannot be analyzed entirely in functional terms

Abstract: A number of popular arguments for dualism start from a premise about an epistemic gap between physical truths about truths about consciousness, and infer an ontological gap between physical processes and consciousness. Arguments of this sort include the conceivability argument, the knowledge argument, the explanatory-gap argument, and the property dualism argument. Such arguments are often resisted on the grounds that epistemic premises do not entail ontological conclusion. My view is that one can legitimately infer ontological conclusions from epistemic premises, if one is very careful about how one reasons. To do so, the best way is to reason first from epistemic premises to modal conclusions (about necessity and possibility), and from there to ontological conclusions. Here, the crucial issue is the link between the epistemic and modal domains. How can one reason from theses about what is knowable or conceivable to theses about what is necessary or possible? To bridge the epistemic and modal domains, the framework of two-dimensional semantics can play a central role. I have used this framework in earlier work (Chalmers 1996) to mount an argument against materialism. Here, I want to revisit the argument, laying it out in a more explicit and careful form, and responding to a number of objections. In what follows I will concentrate mostly on the conceivability argument. I think that very similar considerations apply to the other arguments mentioned above, however. In the final section of the paper, I show how this analysis might yield a unified treatment of a number of anti-materialist arguments

Abstract: Analytic epistemology is traditionally interested in rational reconstructions of cognitive pro- cesses. The purpose of these rational reconstructions is to make plain how a certain cognitive process might eventually result in knowledge or justified beliefs, etc., if we pre-theoretically think that we have such knowledge or such justified beliefs. Typically a rational reconstruction assumes some (more or less) unproblematic basis of knowledge and some justification-preserving inference pattern and then goes on to show how these two su ce to generate the explicandum

Abstract: Knock-down refutations are rare in philosophy, and unambiguous self-refutations are even rarer, for obvious reasons, but sometimes we get lucky. Sometimes philosophers clutch an insupportable hypothesis to their bosoms and run headlong over the cliff edge. Then, like cartoon characters, they hang there in mid-air, until they notice what they have done and gravity takes over. Just such a boon is the philosophers' concept of a zombie, a strangely attractive notion that sums up, in one leaden lump, almost everything that I think is wrong with current thinking about consciousness. Philosophers ought to have dropped the zombie like a hot potato, but since they persist in their embrace, this gives me a golden opportunity to focus attention on the most seductive error in current thinking

Abstract: The notion of conceivability has traditionally been regarded as crucial to an account of modal knowledge. Despite its importance to modal epistemology, there is no received explication of conceivability. In recent discussions, some have attempted to explicate the notion in terms of epistemic possibility. There are, however, two notions of epistemic possibility, a more familiar one and a novel one. I argue that these two notions are independent of one another. Both are irrelevant to an account of modal knowledge on the predominant view of modal reality. Only the novel notion is relevant and apt on the competing view of modal reality; but this latter view is problematic in light of compelling counterexamples. Insufficient care regarding the independent notions of epistemic possibility can lead to two problems: a gross problem of conflation and a more subtle problem of obscuring a crucial fact of modal epistemology. Either problem needlessly hampers efforts to develop an adequate account of modal knowledge. I conclude that the familiar notion of epistemic possibility (and the very term ‘epistemic possibility’) should be eschewed in the context of modal epistemology

Abstract: This paper advances the thesis that we can justifiably believe philosophically interesting possibility statements. The first part of the paper critically discusses van Inwagens skeptical arguments while at the same time laying some of the foundation for a positive view. The second part of the paper advances a view of conceivability in terms of imaginability, where imaginging can be propositional, pictorial, or a combination of the two, and argues that conceivability can, and often does, provide us with justified beliefs of what is metaphysically possible. The notion of scenarios is developed, as is an account of how filling out scenarios can uncover a defeater or, in many cases, strengthen the justification for the relevant possibility statement

Abstract: Zombies recently conjured by Searle and others threaten civilized (i.e., materialistic) philosophy of mind and scientific psychology as we know it. Humanoid beings that behave like us and may share our functional organizations and even, perhaps, our neurophysiological makeups without qualetative conscious experiences, zombies seem to meet every materialist condition for thought on offer and yet -- the wonted intuitions go -- are still disqualefied (disqualified for lack of qualia) from being thinking things. I have a plan. Other zombies -- good (qualia eating) zombies -- can battle their evil (behavior eating) cousins to a standoff. Perhaps even defeat them. Familiar zombies and supersmart zombies resist disqualefication, making the world safe, again, for materialism. Behavioristic materialism. Alas for functionalism, good zombies still eat programs. Alas for identity theory, all zombies -- every B movie fan knows -- eat brains

Abstract:   This paper engages with two compelling challenges to physicalism,each designed to show that the nature of experience is elusive fromthe standpoint of physical science. It is argued that the physicalistis ultimately well placed to meet both challenges

Abstract: David Chalmers’ conceivability argument against physicalism relies on the entailment from a priori conceivability to metaphysical possibility. The a posteriori physicalist rejects this premise, but is consequently committed to psychophysical strong necessities. These don’t fit into the Kripkean model of the necessary a posteriori, and they are therefore, according to Chalmers, problematic. But given semantic assumptions that are essential to the conceivability argument, there is reason to believe in microphysical strong necessities. This means that some of Chalmers’ criticism is unwarranted, and the rest equally afflicts the dualist. Moreover, given that these assumptions are independently plausible, there’s a general case to be made for the existence of strong necessities outside the psychophysical domain