{"agent_id":"chalmers","agent_name":"David Chalmers","slug":"p-zombies-and-the-conceivability-argument","label":"P-zombies and the conceivability argument: does the conceivability of philosophical zombies show that phenomenal consciousness is not entailed by the physical?","topic":"P-zombies and the conceivability argument","question":"Does the conceivability of philosophical zombies show that phenomenal consciousness is not entailed by the physical?","position":"A *philosophical zombie* is a being functionally and physically identical to a conscious human being but with no phenomenal experience whatsoever — no qualia, no \"what it is like\" to be the zombie. The simple form of the conceivability argument runs: zombies are coherently conceivable; coherent conceivability is evidence of metaphysical possibility; if zombies are metaphysically possible, phenomenal consciousness is not logically supervenient on the physical; physicalism requires logical supervenience of consciousness on the physical; therefore physicalism is false. The two-dimensional refinement of this argument deploys *primary intensions* and *secondary intensions*: a sentence is primarily possible if conceivable under its primary intension (consider what the world would have been like if it had been actual), and primary possibility for zombies entails the negation of strict-implication physicalism. The 2D version handles the Kripkean *a posteriori* necessity objection (water = H2O is necessary but not a priori) by distinguishing the primary intension (water as the watery stuff of our acquaintance) from the secondary intension (water as H2O); the zombie scenario is conceivable under the primary intension of any physical-functional description, and that suffices for the anti-physicalist conclusion. Type-B materialism — the a-posteriori physicalism developed by Stoljar, Loar, and the phenomenal-concept-strategy theorists — is the most rigorous opposition; the 2D argument is designed to meet it on its own terms.","paragraphs":[[{"t":"A *philosophical zombie* is a being functionally and physically identical to a conscious human being but with no phenomenal experience whatsoever — no qualia, no \"what it is like\" to be the zombie.","n":[]},{"t":"The simple form of the conceivability argument runs: zombies are coherently conceivable; coherent conceivability is evidence of metaphysical possibility; if zombies are metaphysically possible, phenomenal consciousness is not logically supervenient on the physical; physicalism requires logical supervenience of consciousness on the physical; therefore physicalism is false.","n":[1,2,3]}],[{"t":"The two-dimensional refinement of this argument deploys *primary intensions* and *secondary intensions*: a sentence is primarily possible if conceivable under its primary intension (consider what the world would have been like if it had been actual), and primary possibility for zombies entails the negation of strict-implication physicalism.","n":[]}],[{"t":"The 2D version handles the Kripkean *a posteriori* necessity objection (water = H2O is necessary but not a priori) by distinguishing the primary intension (water as the watery stuff of our acquaintance) from the secondary intension (water as H2O); the zombie scenario is conceivable under the primary intension of any physical-functional description, and that suffices for the anti-physicalist conclusion.","n":[]}],[{"t":"Type-B materialism — the a-posteriori physicalism developed by Stoljar, Loar, and the phenomenal-concept-strategy theorists — is the most rigorous opposition; the 2D argument is designed to meet it on its own terms.","n":[4]}]],"texts":"The Conscious Mind (1996) Chapters 3-4 (the conceivability argument); The Character of Consciousness (2010) Chapters 5-6 ('Consciousness and Its Place in Nature' 2003 and 'The Two-Dimensional Argument Against Materialism' 2010); Constructing the World (2012) Chapters 6-7 on the apriori entailment thesis; 'Does Conceivability Entail Possibility?' (in Gendler & Hawthorne eds. Conceivability and Possibility 2002). Reception: Daniel Stoljar's Ignorance and Imagination (Oxford 2006) and his 'Two Conceptions of the Physical' (Phil. & Phenom. Research 2001); Brian Loar's 'Phenomenal States' (1990, 1997 revised); Joseph Levine's 'Materialism and Qualia: The Explanatory Gap' (Pac. Phil. Q. 1983); Saul Kripke Naming and Necessity (1980); Frank Jackson's 'Epiphenomenal Qualia' (Phil. Q. 1982) and his late conversion in From Metaphysics to Ethics (1998); Stephen Yablo on conceivability and possibility.","works":["The Conscious Mind (1996) Chapters 3-4 (the conceivability argument)","The Character of Consciousness (2010) Chapters 5-6 ('Consciousness and Its Place in Nature' 2003 and 'The Two-Dimensional Argument Against Materialism' 2010)","Constructing the World (2012) Chapters 6-7 on the apriori entailment thesis","'Does Conceivability Entail Possibility?' (in Gendler & Hawthorne eds. Conceivability and Possibility 2002)"],"reception":"Daniel Stoljar's Ignorance and Imagination (Oxford 2006) and his 'Two Conceptions of the Physical' (Phil. & Phenom. Research 2001); Brian Loar's 'Phenomenal States' (1990, 1997 revised); Joseph Levine's 'Materialism and Qualia: The Explanatory Gap' (Pac. Phil. Q. 1983); Saul Kripke Naming and Necessity (1980); Frank Jackson's 'Epiphenomenal Qualia' (Phil. Q. 1982) and his late conversion in From Metaphysics to Ethics (1998); Stephen Yablo on conceivability and possibility.","status":"The conceivability argument is the central anti- physicalist argument in the philosophy of mind since Kripke. The simple form in The Conscious Mind (1996) Chapter 3 was widely engaged and widely contested; the two-dimensional refinement in 'The Two-Dimensional Argument Against Materialism' (in Alter & Walter eds. Phenomenal Concepts and Phenomenal Knowledge 2007, also Character of Consciousness Ch 6) is the more rigorous form designed to meet a-posteriori physicalism. The phenomenal-concept strategy (Loar, Papineau, Balog) and Stoljar's Ignorance and Imagination (2006) develop the type-B materialist response. Frank Jackson, the knowledge argument's original author, converted to physicalism in 1998 partly via the phenomenal-concept strategy. Yablo and others have pressed the conceivability/ possibility gap as a general worry about modal epistemology. The argument remains the central battlefield of contemporary anti-physicalism.","era":"1966-present","discipline":"Philosophy","refs":[{"n":1,"work":"The Two-Dimensional Argument against Materialism","page":"pp. 142–143","canonical":"","quote":"Here I revisit the argument, laying it out in a more explicit and careful form and responding to a number of objections. In what follows I concentrate mostly on the conceivability argument. Similar considerations apply to the other anti- materialist arguments, however, and in the afterword to this chapter, I show how this analysis might yield a unifi ed treatment of many of these arguments.","label":"The Two-Dimensional Argument against Materialism, pp. 142–143"},{"n":2,"work":"The Conscious Mind","page":"pp. 109–110","canonical":"","quote":"It is not unnatural to suppose that zombies might be logically possible but metaphysically impossible in a similar way. If so, this would arguably be enough to save materialism. This is by far the most common strategy of materialists who are persuaded that there is no entailment between physical and phenomenal concepts. On this view, there can be a conceptual gap without a metaphysical gap.","label":"The Conscious Mind, pp. 109–110"},{"n":3,"work":"The Conscious Mind","page":"pp. 84–85","canonical":"","quote":"So even if a zombie world is conceivable only in the sense in which it is conceivable that water is not H2O, that is enough to establish that consciousness cannot be reductively explained.","label":"The Conscious Mind, pp. 84–85"},{"n":4,"work":"The Conscious Mind","page":"p. 81","canonical":"","quote":"One can also do things more directly, making the case against reductive explanation without explicitly appealing to logical supervenience. I have taken that route elsewhere, but here I will give the more detailed analysis to allow a fuller case. All the same, the case against reductive explanation and the critique of existing reductive accounts (in section 2 onward) should make sense even without this analysis.","label":"The Conscious Mind, p. 81"}],"answer":null,"siblings":[{"slug":"the-hard-problem-of-consciousness","label":"The hard problem of consciousness: is the explanation of phenomenal experience a problem distinct in kind from the explanation of the cognitive functions associated with consciousness?"},{"slug":"naturalistic-dualism-and-type-f-monism","label":"Naturalistic dualism and type-F monism: what is the right positive view about the place of consciousness in nature?"},{"slug":"the-extended-mind-and-active-externalism","label":"The extended mind and active externalism: can cognition extend beyond the boundaries of skin and skull into the environment?"},{"slug":"virtual-realism-and-the-simulation-hypothesis","label":"Virtual realism and the simulation hypothesis: are virtual entities real, and is the simulation hypothesis a skeptical scenario?"}]}