¹ Lewis, D. ‘New work for a theory of universals’, Australasian Journal of Philosophy 61 (1983), 343–77Google Scholar. See also Jackson, F., From Metaphysics to Ethics (Oxford: Clarendon, 1998)Google Scholar and Chalmers, D. and Jackson, F., ‘Conceptual Analysis and Reductive Explanation’, Philosophical Review 110 (2001), 315–61Google Scholar.

² D. Chalmers and F. Jackson, ‘Conceptual Analysis and Reductive Explanation’, op. cit.

³ Act 1, Sc. 4.

⁴ Mill, J. S., A System of Logic, The Collected Works of John Stuart Mill (Toronto: University of Toronto Press, 1963)Google Scholar, Vols. 7–8; Morgan, C., Emergent Evolution (London: Williams and Norgate, 1923)Google Scholar; Broad, C. D., Mind and Its Place in Nature (London: Routledge and Kegan Paul, 1925)Google Scholar.

⁵ See for example Jackson's, F. ‘Finding the Mind in the Natural World’ in The Nature of Consciousness, edited by Block, Ned, Flanagan, Owen and Güzeldere, Güven (Cambridge, MA: MIT Press, 1997), 483–92Google Scholar.

⁶ Popper, Karl and Eccles, John suggested in The Self and Its Brain (New York: Springer International, 1977)CrossRefGoogle Scholar that the mind could exploit quantum indeterminacy to operate in the physical world, neural synapses being the ‘seat of the soul’, with no apparent violation of physical law. It follows that there could be an MPD of an Eccles-Popper world that lacked mentality; that is, that contained zombies. Of course, under the right choice of measurement sequences the Eccles-Popper world would look extremely unlikely relative to the calculated quantum probabilities of synaptic transmission, but extremely unlikely is a long, long way from impossible.

⁷ This idea is deployed by Brian Garrett in the context of an anti-zombie argument. See his ‘Causal Essentialism versus the Zombie Worlds’, Canadian Journal of Philosophy (forthcoming).

⁸ Such a dualist would be endorsing a form of what is often called Russellian Monism, but not one which could be allowed to count as a form of physicalism. See D. Chalmers, The Character of Consciousness (Oxford: Oxford University Press, forthcoming) for a discussion of the role of Russellian Monism in the general conceivability argument against physicalism (a version of the argument is available online at http://consc.net/papers/2dargument.html).

⁹ For example, the explicit clause asserting that each b is different from a. In addition, here and below I ignore outer universal quantification for simplicity of presentation.

¹⁰ One philosopher who has argued against the coherence of Type 5 dependence is Strawson, Galen who, in ‘Realistic Monism: Why Physicalism Entails Panpsychism’ (Consciousness and its Place in Nature: Does Physicalism Entail Panpsychism?, edited by Freeman, A. (Exeter: Imprint Academic, 2006), 3–31)Google Scholar, takes the impossibility of Type 5 dependence to rule out any form of genuine emergence of consciousness from a purely physical substrate and thus to support panpsychism (which is, in my view, best understood as a form of Type 4 dependence, about which see below).

¹¹ Paul Teller can perhaps be read as advocating such a view, although it may be that he is only endorsing the weaker claim that quantum systems exhibit a kind of irreducible ontological holism (see his ‘Relational Holism and Quantum Mechanics’, British Journal for the Philosophy of Science 37 (1986), 71–81). I think that discussions of emergence in quantum mechanics tend to miss the distinction between holism and Type 5 dependency. This is often coupled with the assimilation of Type 3 dependency to ‘part whole reductionism’. But while Type 3 dependence is compatible with mereological reductionism it is not equivalent to it, as the example of mass illustrates.

¹² Putnam, H., ‘The Mental Life of Some Machines’ in Mind, Language and Reality: Philosophical Papers, Vol. 2 (Cambridge: Cambridge University Press, 1975), 412CrossRefGoogle Scholar.

¹³ Stephen Yablo has offered what I take to be a surprisingly fruitful analogy between the mind-matter relation and the determinable-determinate relation (‘Mental Causation’, The Philosophical Review 101 (1992), 245–80). There are problems with trying to take the idea literally, however (for some, see Cox, E., ‘Crimson Brain, Red Mind: Yablo on Mental Causation’, Dialectica 62:1 (2008), 77–99)CrossRefGoogle Scholar.

¹⁴ Leaving aside the ‘shifted particle’ worlds, it is an explicitly noted, if unfortunate, consequence of the view that mental properties are extrinsic that a creature that failed to stand in the requisite relations would thereby qualify as a zombie, no matter how physically (hence behaviorally) similar it might be to one of us; see Dretske, F., Naturalizing the Mind, (Cambridge, MA: MIT Press, 1995)Google Scholar. This seems almost a reductio of such accounts of the mental, with the added ‘bonus’ of strongly supporting the general intuition of the possibility of zombies.

¹⁵ Of course, there remain a host of dualist views in which the mental bears no relation of determination upon the physical (pretty much all the usual suspects: occasionalism, parallelism, etc.). But this sort of dualist will have no reason to deny that there are worlds which are MPDs of the actual world that lack mentality. Zombies remain possible.

¹⁶ This paper began as a commentary on Alexandru Manafu's presentation at the 2008 CPA meeting and I would like to thank Alexandru for sparking my reflections on this topic. Additional comments of David Chalmers have been very helpful, though of such a generous extent that they could not all be addressed here.