A Posteriori Physicalists Get Our Phenomenal Concepts Wrong

Abstract

Dualists say plausible things about our mental concepts: there is a way of thinking of pain, in terms of how it feels, which is independent of causal role. Physicalists make attractive ontological claims: the world is wholly physical. The attraction of a posteriori physicalism is that it has seemed to do both: to agree with the dualist about our mental concepts, whilst retaining a physicalist ontology. In this paper I argue that, in fact, a posteriori physicalism departs from the dualist's intuitive picture of our phenomenal concepts in just as radical a manner as more traditional forms of physicalism. Whereas the physicalism of David Lewis and David Armstrong is counterintuitive in holding that our only way of thinking about pain is in terms of its causal role, the physicalism of David Papineau and Brian Loar departs from common sense in holding that our phenomenal concept of pain is opaque: thinking of pain in terms of how it feels reveals nothing of what it is for something to feel pain. The arguments of David Chalmers and Frank Jackson against a posteriori physicalism involve general claims about all concepts. In contrast, my argument makes a claim only about phenomenal concepts: phenomenal concepts are not opaque.

Notes

¹See also Harman 1990, Dretske 1995, Rey 1995.

²For some examples of a posteriori physicalism, see Levine 1983, Loar 1990, 2003, Papineau 1993a; 2002, Tye 1995, Lycan 1996, Hill 1997, Hill and McLaughlin 1999, Block and Stalnaker 1999, and Perry 2001.

³I am assuming that when two human beings think about the (determinable property of the) feeling of pain in terms of how it feels, they employ the same kind of concept. Hence I can talk about ‘the phenomenal concept of pain’.

⁴Beyond essential properties which are trivial, e.g. being self-identical, or concern the very general ontological kind of the referent, e.g. being a property, being a countable object.

⁵We might alternatively define mildly external concepts as concepts possession of which involves implicit knowledge of how reference is fixed. This definition would avoid many of the tricky issues described in note 9, but departs from Chalmers's way of setting things up.

⁶Same qualification as with mildly opaque concepts, see note 4.

⁷Jackson 1998 has a very similar two-dimensional framework which also excludes radically opaque concepts, and which he uses to oppose a posteriori physicalism.

⁸We need to add ‘centres’ to the worlds considered as actual to evaluate the primary intension. Centres would also have to be built into a satisfactory definition of a mildly opaque concept, e.g. we would need centring to distinguish the watery stuff on Earth from the watery stuff on Twin Earth. I ignore this complication.

⁹There are extra complexities here. Could we not bring facts about reference into the worlds being considered for verification of <that stuff is XYZ>? For example, we could suggest that this proposition is true at the world considered as actual where a recognitional capacity picking out XYZ was activated in me at the time (we can pick out the relevant individual and time with reference to the centre of the world) I thought this thought (and no other referential capacity was activated, etc.). If this is fair game, then the physicalist can reply that the proposition Q <all the actual physical facts obtain but no badger has ever felt pain> is true at the world considered as actual where (i) all the actual physical facts obtain (ii) a Chalmers-style phenomenal concept referring to a non-physical property F is activated in me when I think about pain, (iii) badgers don't have F, but is false at the world considered as actual where (i) all the actual physical facts obtain, (ii) a Papineau-style phenomenal concept referring to c-fibres’ firing is activated in me when I think about pain. This would result in pain having distinct primary and secondary intensions (the secondary intension being dependent on the referent of the actual concept activated in me when I think about pain), which would render false another crucial premise in Chalmers's argument: that phenomenal concepts have identical primary and secondary intensions (which allows the move from there being a world considered as actual where there are zombie badgers to there being a world considered as counterfactual where there are zombie badgers).

But there is another problem for the physicalist. One might think that the physicalist ought to hold that complete knowledge of the actual physical facts would reveal that ‘pain’ refers to c-fibres’ firing, in which case we can rule out a priori that all the actual physical facts obtain in the absence of pain (because the actual physical facts entail that ‘pain’ refers to c-fibres’ firing). I think there is room for the physicalist to deny this. She could say that, if there is actually a non-physical property closely associated with c-fibres’ firing, then ‘pain’ refers to that non-physical property, but that if there is actually no such non-physical property closely associated with c-fibres’ firing, then ‘pain’ refers to c-fibres’ firing (this strategy would be similar to the ‘conditional analysis’ defence of physicalism: Hawthorne 2002, Stalnaker 2002, Braddon-Mitchell 2003). We could tell a similar story about the conceivability of all the actual physical facts obtaining in the absence of that stuff, so there is no reason to think that phenomenal concepts are unique in this regard.

Chalmers also suggests that the mere fact that there is a minimal physical duplicate of our world, call it W, which verifies the proposition Q, is enough to refute physicalism, as the actual world differs from W in that Q is actually false (actual badgers feel pain). I think the physicalist can plausibly deny that there is any minimal physical duplicate of the actual world which verifies Q—on the grounds that if there are in actuality only physical properties ‘pain’ refers to a physical property—whilst making sense of the conceivability of Q in the following way: under the hypothesis that dualism actually obtains, there is a world considered as counterfactual at which Q is true.

Alternatively, I think the physicalist could concede that strictly speaking zombies (including zombie badgers) are ruled out a priori, but only because the physical facts entail facts about the reference of phenomenal concepts, not because phenomenal concepts can be analysed into functional concepts. This would still avoid the difficulties with the standard a priori physicalist position: it would allow that we have a special way of thinking about experiences which is not conceptually connected to functional role, which is the new concept Mary learns when leaving her black and white room, etc. The physicalist may still be obliged to explain why we find it is difficult to accept that ‘pain’ refers to c-fibres’ firing, in a way that we don't find it difficult to accept that that stuff refers to H₂O, but physicalists have gone to some lengths to do this, e.g. Papineau 1993a.

¹⁰See Dretske 1994 and Millikan 1984 for theories that involve a commitment to radically opaque concepts. In the theories of phenomenal concepts offered by a posteriori physicalists, phenomenal concepts are generally conceived of as some kind of radically opaque concept, e.g. demonstratives [Papineau 1993b; Perry 2001, or grounded in recognitional capacities [Loar 1990 or facts about teleology [Papineau 2002, 2007 rather than a priori content. Chalmers and Jackson [e.g. Jackson 1998: 37–42] often claim that their two-dimensional framework is consistent with the causal theory of reference, and indeed it is in the sense that the primary intension might express certain causal/historical connections between the referent and employments of the concept. However, their framework is inconsistent with meta-semantic theories according to which those causal/historical relations, or whatever facts determine reference, are not a priori associated with the concept. This is still a highly contentious meta-semantic assumption, which takes away from the dialectical strength of Chalmers's anti-physicalist arguments.

¹¹Suppose I meet Bob at a party and form a recognitional capacity which allows me to refer to Bob. Two months later I wake up and think, ‘I wonder if I'll met that guy again’, where I employ my recognitional capacity in order to think about Bob. I can't remember Bob's name, or what he looks like. The only thing I remember about Bob is that he is a guy I met at a party, but this does not uniquely identify him, as I have met lots of guys at parties. This seems to me a plausible example of a radically opaque concept.

¹²My linguistic intuitions tell me that ‘to be in pain’ just is, and is nothing more than, to feel pain (to think this is not to beg the question against materialism; many materialists, e.g. David Lewis 1980: §VIII], and David Papineau 2002: 82] agree). But this terminological debate over whether ‘being in pain’ is semantically equivalent to ‘feeling pain’ is utterly unimportant, for the simple reason that we can choose to explicitly focus, as I have mostly done here, on the feeling of pain itself, and ask whether that is a physical property.

¹³See, for example, Lewis 1980: §VIII] and Papineau 2002: 82].

¹⁴Or suppose that to feel pain is to be in a certain a functional state. If the concept of the feeling of pain is translucent, then the concept will partly reveal the functional nature of the feeling of pain, which is again inconsistent with the claims of the a posteriori physicalist.

¹⁵Why would Loar be committed to TDI if he thought that phenomenal concepts were translucent and that physical concepts were transparent? Answer: if the phenomenal concept of pain is translucent, then it reveals an aspect, call it a, of what it is to feel pain. If the physical concept that denotes the feeling of pain reveals the complete nature of the feeling of pain, then it will reveal the nature of a (as an aspect of that complete nature). If the physical concept conceives of a in physical terms, and the phenomenal concept conceives of a in phenomenal terms, then the physical and the phenomenal concept reveal the nature of a under conceptually distinct modes of presentation (according to a posteriori physicalism).

¹⁶Both Loar 1990 and Papineau [2002] have put effort into explaining what is special about phenomenal concepts, but not specifically what is special about phenomenal concepts such that TDI is or might be true. Loar avoids the issue by not distinguishing between transparent/translucent concepts on the one hand and radically opaque concepts on the other. Papineau, as I explain below, has recently explicitly committed to phenomenal concepts' being opaque, and so does not need to accept TDI. As I also explain below, the primary aim of Papineau and Loar is to give an account of phenomenal concepts which enables them to make sense of psycho-physical identities' being exceptions to what Papineau calls ‘the transparency thesis’ and Loar calls ‘the semantic premise’, a principle which is not equivalent to TDI.

¹⁷I take it that it follows from atomic concepts' being ‘related to reality by facts external to our a priori grasp’ that atomic concepts are neither transparent nor translucent.

¹⁸As I will discuss below, it is plausible to think that, in having a phenomenal concept of pain whilst introspecting one's pain, one can know for certain that that concept is perfectly satisfied. If this is the case, and if the phenomenal concept of pain is transparent, then mere introspection can give us insight into the nature of reality. Merely by introspecting I can know the nature of a property, and know that that property is instantiated. But even if this is so, it is not the mere transparency of the phenomenal concept which allows us insight into the nature of reality; it is transparency in conjunction with the certainty that the concept is perfectly satisfied. There is nothing mysterious about the notion of transparency itself.

¹⁹More precisely: the physicalist cannot rely on the concept of c-fibres’ firing being mildly opaque unless she is a funny physicalist (see response to Objection 3 below).

²⁰‘Funny peculiar’ (in a non-pejorative sense) rather than ‘funny ha ha’. For some examples of funny physicalism, see Russell 1927, Eddington 1928, Feigl 1967, Maxwell 1979, Lockwood 1989, Strawson 1994, 2003, 2006, Chalmers 1996, Griffen 1998, and Stoljar 2001.

²¹Again, if we read this as merely a commitment to transparency, it need not imply a priori insight into extra conceptual reality. It is only the conjunction of (i) phenomenal concepts are transparent (ii) phenomenal concepts are perfectly satisfied, which implies that our phenomenal concepts can tell us something about reality.

²²See Stoljar 2001 for a detailed account of these two ways of defining what a ‘physical property’ is.

²³Most funny physicalists take views according to which there are only structural properties to be incoherent (Strawson 2003, Stoljar 2001), but other philosophers defend the coherence of such a metaphysical view (Ladyman and Ross 2007, van Fraassen 2006).

²⁴More precisely: standard physicalists are only committed to the kind of properties which physics reveals to us the nature of, and to properties which are a priori entailed by the kind of properties which physics reveals to us the nature of.

²⁵See Goff [forthcoming] for a decisive refutation of funny physicalism, and also of a priori physicalism. That paper also contains an argument against a posteriori physicalism, but one of the premises (that ghosts are possible if conceivable) relies on the arguments in this paper. Goff [forthcoming] and the paper you are now reading can be read in conjunction as an attack on all forms of physicalism.

²⁶See note 5 of Papineau [2002: 85] for an explicit rejection of this strategy for making sense of the a posteriori identity between physical states and conscious states.

²⁷As I said in notes 18 and 21, this does not contradict what I have claimed earlier about the transparency of a concept not implying a priori insight into the nature of reality. It is only the transparency of a phenomenal concept in conjunction with the certainty that that concept is satisfied which has implications for how the world is. An eliminativist about consciousness could consistently claim that our phenomenal concepts are transparent but not satisfied, and hence that those concepts afford us no insight into the nature of reality.

²⁸I am not here making the more controversial claim that I grasp all aspects of my pain. We can take it that the certainty I am talking about is with reference to some determinable concept of pain, rather than some highly specific determinate of it. I can be certain, in the moment of feeling pain, that the highly determinable concept of pain I am employing is perfectly satisfied.

²⁹Other kinds of physicalists have appeared to suggest that folk concepts of conscious states are imperfectly realized, e.g. Lewis 1995 and arguably Dennett 1991. However, a posteriori physicalists tend not to want to be revisionary about our phenomenal concepts. Perhaps there is room for a hybrid between the physicalism of Papineau/Loar and the physicalism of Lewis/Dennett: a form of a posteriori physicalism which takes our phenomenal concepts to be imperfectly satisfied. Until such a view is spelt out, I shall ignore it.

³⁰Strictly speaking, Nida-Rümelin's argument is against all forms of physicalism, rather than merely a posteriori physicalism. However, the premise which excludes a priori physicalism, the principle of ‘Cognitive Independence of Physical and Phenomenal Properties’, is only very briefly defended. If this premise were added to my argument, my argument would also be (at least as) effective against all forms of standard physicalism.

³¹It is clear I think from the context that Nida-Rümelin intends something like this story to generalize to all concepts.

³²I interpret David Lewis as claiming that we have a transparent flaccid concept of being a pain, and a mildly opaque rigid concept of being the actual state which is human pain, both of which conceive of pain in terms of its causal role [Lewis 1980.

³³I owe a huge debt of gratitude to David Papineau for invaluable assistance over the last five years in developing my arguments against him, and to Galen Strawson for giving me the confidence to pursue a wacky view just because it happens to be true. I am also grateful for the comments of the journal's anonymous reviewers, which resulted in a much improved paper. I revised this paper while I was a Post-Doctoral Research Fellow in the AHRC project Phenomenal Qualities, at the University of Hertfordshire.