Abstract
The “hard problem” of consciousness is a challenge for explanations of the nature of our phenomenal experiences. Chalmers has claimed that physicalist solutions to the challenge are ill-suited due, in part, to the zombie argument against physicalism. Perry has suggested that the zombie argument begs the question against the physicalist, and presents no relevant threat to the view. Although seldom discussed in the literature, I show there is defensive merit to Perry’s “parry” of the zombie attack. The success of the maneuver suggests a slight softening of the hard problem of consciousness for physicalists.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
Not all versions of physicalism rely on a particular conception of physical properties (Ney 2008). For example, via negativa accounts only hold that nothing that exists is fundamentally mental, and so do not depend on a positive characterization of physical properties (see e.g. Montero and Papineau 2005). Other types of theories do rest on other conceptions of physical properties, but are not targets of the zombie argument. The most well-known is Russellian Monism, which rests in part on an “object-based” conception of physical properties. Roughly, under this conception, some physical properties are part of the intrinsic nature of paradigmatic physical objects, or priori/logically supervene on these intrinsic properties (Stoljar 2001, p. 396). These sorts of physical properties are “inscrutable”, in that they are distinct from the sort of relational physical properties that make up fundamental physics. According to Russellian monism, some of these inscrutable physical properties are phenomenal (or “proto”-phenomenal). I discuss why the view avoids the zombie argument in footnote 9. For further discussion of the view, see Alter and Nagasawa (2012).
We can understand metaphysical supervenience, roughly, as follows: for any two sets of facts A and B, the B facts metaphysically supervene on the A facts iff there are no two metaphysically possible worlds that are identical in their A facts but not in their B facts. Chalmers (1996, p. 366, n. 30) takes the notion of possible world as primitive in his discussion. I will do the same.
The precise notion of supervenience relied on by Chalmers in defining physicalism is rather technical, and frames matters in terms of logical and conceptual possibility (for a summary statement, see Chalmers 1996, p. 40–41). I do not believe the present discussion hinges on these details so I have excluded them, and described matters in terms of metaphysical possibility.
Chalmers (2002, p. 148) provides no account of what good reasoning is, or how we are to abstract away from our cognitive limitations. Instead, he takes certain rational notions as primitive, and this applies to the (intuitive) idea that some justifications can defeat others.
According to Chalmers, in perceptual imagination, we have a mental image that is similar to a perceptual experience we might have if S were the case (I imagine seeing a blue chair, when asked to conceive of a blue chair). Alternatively, positive conceivability might take the form of coherent modal imagination. We modally imagine when:“one has a positive intuition of a certain configuration within a world, and takes that configuration to satisfy a certain description” (Chalmers 2002, p. 151), and we modally imagine that S if we imagine a world or situation, where reflection reveals it to be a world/situation in which S holds. We modally imagine situations which we cannot readily perceptually imagine—such as two states of affairs that are perceptually indistinguishable, or conceivable but not perceivable entities (for example, an imperceptible being). Or so says Chalmers.
What follows is a simplification of Chalmers’ preferred way of schematizing the argument (see e.g. Chalmers 2009).
Once T is included, any world that satisfies PT is a minimal world with respect to P (Chalmers and Jackson 2001). Thus, a possible world at which PTI is true will be a minimal physical duplicate of the actual world.
The argument does not succeed, however, if one is a Russellian monist, for P does not include facts related to inscrutable physical properties. Thus, in the two-dimensional formulation of the argument, the consequent in (Z3), and the conclusion in (Z4), are disjunctive: either physicalism (of the relevant brand) is false, or Russellian monism is true (see e.g. Chalmers 2009).
For his part, Chalmers (2010, p. 180) rejects the idea that these arguments genuinely parallel his argument.
See, for example, Antony and Levine (1997), Bishop (2006), Haug (2009), Hopkins (1978), Lowe (2000), Papineau (2002), Sturgeon (1998), and Witmer (2000). The argument goes by many names, including the “ovedetermination argument” (Sturgeon 1998), and “the argument from causal closure”. It is closely related to the exclusion argument regarding mental causation and reductive physicalism (Kim 1998).
Papineau (2002) points out that one can follow Davidson (1980), and identify the relata of causation as events, as I sometimes do, or as instantiations of properties, or as facts more generally. Papineau (2002) opts for the latter, on the grounds that a causal argument that employs a Davidsonian notion of events only leads to the conclusion that phenomenal and physical descriptions pick out the same event. However, if the relata are facts, then we can identify phenomenal and physical properties, which is a much stronger conclusion. In contrast, Sturgeon (1998) and Witmer (2000) claim that a Davidsonian notion of events is presupposed by the causal argument. For present purposes I remain non-committal on issues concerning the relata of causation.
As stated, the argument is not valid, since the final step is abductive. To make the argument deductive, the third premise can be replaced with the Exclusion Principle: if an event, F, sufficiently causes another event G, then there is no other event, F*, which causes G and does not metaphysically supervene on F (see Kim 1998). Alternatively, one can make Closure a stronger claim, which builds in exclusion: physical events only have physical events as causes (cf. Chalmers 1996, p. 157). So the argument can come in both abductive and deductive forms.
Briefly: it is not clear what account of causation is consistent with both Closure and No-Overdetermination but allows for phenomenal experiences to be causally influenced, but impotent (Walter 2009). I think this is even more plausible when it comes to physical properties, though I won’t pursue the issue here.
My argument here is to the conclusion that phenomenal states qua physical properties are causally efficacious. In contrast, one might think that Efficacy relates to efficacy qua phenomenal properties. One might worry that both forms of efficacy cannot hold without threat of overdetermination. This concern is closely related to the “exclusion problem” of Kim (1998): roughly, if physical properties can do all the causal work (i.e. provide a sufficient cause of a physical event), then mental properties are out of a job (their causal powers are superfluous). However, the brand of physicalism we are interested in is reductive (Chalmers and Jackson 2001), and so only supposes a commitment to the first form of causal efficacy.
In place of No-Supervenience Sturgeon uses the simple truth of dualism as the fourth principle: “Mental events are not physical events” (Sturgeon 1998, p. 414). His formulation, however, also defines dualism as entailing Efficacy, and I want the dualist principle to be more neutral, hence, I have used No-Supervenience as the fourth principle.
Alternatively, if the interactionist rejects No-Overdetermination, she can endorse Closure, holding that phenomenal events are efficacious but overdetermining causes of physical events (Mills 1996). But an epiphenomenalist will also likely endorse No-Overdetermination, hence creating a different source of disagreement with the (overdeterministic) interactionist.
Another way of summarizing the point is to say that for the physicalist the actual world is a minimal world with respect to PC, but not P (Chalmers and Jackson 2001, p. 317). In which case, any other world which satisfies PCTI is a minimal physical and causal duplicate of the actual world. But no such duplicate is a zombie world, and so zombie worlds are not (negatively) ideally conceivable.
Though an implication of my argument is that a physicalist cannot endorse the ideal conceivability of \(PTI \& \lnot Q\), on pain on contradiction with the truth of C (assuming C is not part of, or entailed by, P).
Interestingly, there is some similarity between my take on the zombie argument, and a recent interpretation of Leibniz’s “Mill Argument” by Duncan (2012). Roughly, Duncan claims that Leibniz uses the argument to both explain why materialism is false, and persuade us that it is false. For a reply to Duncan, see Lodge (2014).
References
Alter T, Nagasawa Y (2012) What is Russellian monism? J Conscious Stud 19(9–10):67–95
Antony LM, Levine J (1997) Reduction with autonomy. Noûs 31(s11):83–105
Bishop RC (2006) The hidden premiss in the causal argument for physicalism. Analysis 66(289):44–52
Brown R (2010) Deprioritizing the a priori arguments against physicalism. Journal of Consciousness Studies 17(3–4):47–69
Chalmers DJ (1995) Facing up to the problem of consciousness. J Conscious Stud 2(3):200–219
Chalmers DJ (1996) The conscious mind: in search of a fundamental theory. Oxford University Press, Oxford
Chalmers DJ (2002) Does conceivability entail possibility? In: Gender T, Hawthorne J (eds) Conceivability and possibility. Oxford University Press, Oxford
Chalmers DJ (2003) Consciousness and its place in nature. In: Stich S, Warfield F (eds) Blackwell guide to philosophy of mind. Blackwell, Oxford
Chalmers DJ (2004) Imagination, indexicality, and intensions. Philos Phenomenol Res 68(1):182–190
Chalmers DJ (2009) The two-dimensional argument against materialism. In: McLaughlin B, Beckermann AS (eds) The Oxford handbook of the philosophy of mind. Oxford University Press, Oxford
Chalmers DJ (2010) The character of consciousness. Oxford University Press, Oxford
Chalmers DJ (2012) Constructing the world. Oxford University Press, Oxford
Chalmers DJ, Jackson F (2001) Conceptual analysis and reductive explanation. Philos Rev 110:315–360
Davidson D (1980) Essays on actions and events. Clarendon Press, Oxford
Duncan S (2012) Leibniz’s mill arguments against materialism. Philos Q 62(247):250–272
Frankish K (2007) The anti-zombie argument. Philos Q 57(229):650–666
Funkhouser E (2002) Three varieties of causal overdetermination. Pac Philos Q 83(4):335–351
Gillett C, Witmer DG (2001) A physical need: physicalism and the via negativa. Analysis 61(272):302–309
Haug MC (2009) Two kinds of completeness and the uses (and abuses) of exclusion principles. South J Philos 47(4):379–401
Hopkins J (1978) Mental states, natural kinds and psychophysical laws. In: Proceedings of the Aristotelian Society, supplementary volumes, pp 221–236
Jackson F (1998) From metaphysics to ethics: a defense of conceptual analysis. Oxford University Press, Oxford
Judisch N (2008) Why non-mental wont work: on hempels dilemma and the characterization of the physical. Philos Stud 140(3):299–318
Kim J (1998) Mind in a physical world: an essay on the mind-body problem and mental causation. MIT Press, Cambridge
Kirk R (1974) Zombies vs materialists. Proc Aristot Soc 48:135–152
Kirk R (2005) Zombies and consciousness. Oxford University Press, Oxford
Lachs J (1963) Epiphenomalism and the notion of cause. J Philos 60:141–146
Lodge P (2014) Leibniz’s mill argument against mechanical materialism revisited. Ergo Open Access J Philos 1:79–99
Lowe EJ (2000) Causal closure principles and emergentism. Philosophy 75(04):571–585
Mills E (1996) Interactionism and overdetermination. Am Philos Q 33:105–117
Montero B, Papineau D (2005) A defence of the via negativa argument for physicalism. Analysis 65(287):233–237
Ney A (2008) Defining physicalism. Philos Compass 3(5):1033–1048
Norton J (2003) Causation as folk science. Philos Impr 3(4):1–22
Papineau D (2002) Thinking about consciousness. Oxford University Press, Oxford
Papineau D (2009) The causal closure of the physical and naturalism. In: McLaughlin B, Beckermann AS (eds) The Oxford handbook of the philosophy of mind. Oxford University Press, Oxford
Perry J (2001) Knowledge, possibility, and consciousness. Mit Press, Cambridge
Perry J (2004) Replies. Philos Phenomenol Res 68(1):207–229
Piccinini G (2015) Access denied to zombies. Topoi. doi:10.1007/s11245-015-9323-6
Schaffer J (2003) Overdetermining causes. Philos Stud 114(1):23–45
Spurrett D, Papineau D (1999) A note on the completeness of physics. Analysis 59(261):25–29
Stoljar D (2001) The conceivability argument and two conceptions of the physical. Philos Perspect 15:393–413
Sturgeon S (1998) Physicalism and overdetermination. Mind 107(426):411–432
Walter S (2009) Epiphenomenalism. In: McLaughlin B, Beckermann AS (eds) The Oxford handbook of the philosophy of mind. Oxford University Press, Oxford
Witmer DG (2000) Locating the overdetermination problem. Br J Philos Sci 51(2):273–286
Acknowledgments
This paper was initially conceived several years ago. Since then, it has benefited greatly from the input of a number of people. Thanks are due first off to Ben Caplan, Tim Schroeder, Chris Tillman, and Vlad Vloavic for helpful discussions early on. A previous incarnation of the paper, titled “Dualism, Function, and the Limits of Conceivability”, was presented in 2009 at the 101st Meeting of the Southern Society for Philosophy and Psychology, in Savannah, GA. Thanks to all who attended, and especially Bryce Huebner, Blake Myers, and Justin Sytsma. A number of people read the manuscript (in various forms) including: Peter Carruthers, Lizzie Schechter, Bénédict Veillet, Melissa Ebbers, Dave McElhoes, Vlad Vloavic, Gualtiero Piccinini, and Richard Brown. Thanks to all of them for their very helpful feedback. Finally, a special thanks to the two anonymous referees for this journal, whose critical feedback substantially improved the paper, and the editors of the special issue Glenn Carruthers and Liz Schier.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ritchie, J.B. The Zombie Attack, Perry’s Parry, and a Riposte: A Slight Softening of the “Hard Problem” of Consciousness. Topoi 36, 55–65 (2017). https://doi.org/10.1007/s11245-016-9369-0
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11245-016-9369-0