Philosophy Compass 6 (4), 2011, 267-281 Phenomenal concepts Pär Sundström, Umeå University Abstract: It's a common idea in philosophy that we possess a peculiar kind of "phenomenal concepts" by which we can think about our conscious states in "inner" and "direct" ways, as for example, when I attend to the way a current pain feels and think about this feeling as such. Such phenomenal ways of thinking figure in a variety of theoretical contexts. The bulk of this article discusses their use in a certain strategy – the phenomenal concept strategy – for defending the physicalist view that conscious states are reducible to brain states. It also considers, more briefly, how phenomenal concepts have been used to defend dualism about consciousness, and how they have been used to explain our special access to our consciousness. It concludes with a discussion about whether, and in what more precise sense of the term, we at all possess "phenomenal concepts" of our conscious states. 1 Introduction 'Phenomenal concept' is a technical term that is specified in different ways in the literature, but the following general idea can serve as our initial focus. We can think about conscious states – the idea is – under both phenomenal and nonphenomenal concepts. The former are concepts we employ to think about conscious states in "inner" and "direct" ways; the latter concepts we employ to think about them in "outer" and "indirect" ways. For example, I employ a phenomenal concept of pain when I inwardly attend to the way a current pain feels and think about this feeling as such. For an example of a nonphenomenal concept, consider a case where I think "what bothers Sarah must be unpleasant", not knowing whether Sarah is bothered by a pain or something else. If she is in fact bothered by a pain, then my thought concerns that pain, but my concept "gets to" the pain through an outer and indirect route and is therefore "nonphenomenal". 2 Phenomenal ways of thinking about consciousness figure in different contexts in philosophy. At present, they are most strongly associated with a certain strategy – the phenomenal concept strategy – for defending the physicalist view that conscious states are reducible to brain states. To think about consciousness in inner and direct phenomenal ways is very different from thinking about the brain in terms of its biological properties. According to the phenomenal concept strategy, this difference in ways of thinking can deceive us into supposing that the thinkings must concern different and dissociable things. But there is no reason to so suppose, because, familiarly, different ways of thinking might concern the same thing; as when I think about myself in an inner way, as I, and also think about (what turns out to be) myself as the shopper who set off the alarm. However, phenomenal ways of thinking about consciousness have been invoked for purposes other than defending physicalism as well. In direct opposition to the phenomenal concept strategy, they have been invoked to defend dualism about consciousness. They have also been invoked to explain our special access to our own consciousness. The bulk of this article concerns the (physicalist) phenomenal concept strategy. Section 2 explains what the strategy is, and section 3 discusses some challenges to it. Section 3 also illustrates, in passing, the use of phenomenal concepts in arguments for dualism. Section 4 briefly considers how phenomenal concepts have been invoked to explain our special access to our own consciousness. Section 5 summarises and extends a bit through a discussion about whether, and in what more precise sense of the term, we at all possess "phenomenal concepts" of our conscious states. A terminological note: Phenomenal concepts are variously said to be concepts of "conscious states", "phenomenal properties", or of ways that things are subjectively "like" for a subject. For present purposes, we may take these to be equivalent: a phenomenal property may be understood as a type of conscious state, or, equivalently, as a way that things might be subjectively like for a subject. 3 2 The phenomenal concept strategy 2.1 Physicalism and its challenges According to physicalism, conscious states are reducible to brain states, or other physical states. 1 Reduction is sometimes understood in terms of identity between conscious states and brain states; sometimes in terms of necessary connections between the two. But on either understanding, the view is that conscious states are as intimately tied to brain states as water is to H2O, liquidity to loose molecular bonding, or the global pattern of a pixel grid to the activation of its individual pixels (cf. Lewis 1994). It's not just that consciousness is connected to the brain in some regular or law-like way; rather, it is in some sense "nothing over and above" what goes on in the brain. It might seem counter-intuitive that our rich inner world of consciousness should be thus reducible to brain states. This (counter-)intuition has also been developed in various arguments against or challenges for physicalism, prominent among which are the following three. The explanatory gap (Levine 1983; 2001). Theoretical reductions seem typically to be somehow explanatory. For example, the "plasma-like" cohesiveness and malleability characteristic of liquidity seems to be explained by the loose molecular bonding that underlies or is identical with it. By contrast, it seems that no account of what goes on in the brain while I experience red could explain what this is like subjectively. The "appearance of contingency" (see Kripke 1972/1980, 144-155; Chalmers 1996; 2010). On the face of it, it seems that the brain state I'm in right now could obtain without the conscious state I'm in right now. If physicalism is true, this is an illusion: 1 Henceforth, 'brain state' will abbreviate 'brain state or other physical state'. Physical states that are not confined to the brain but that might be part of what consciousness reduces to include states of the body (O'Regan and Noë 2001; Noë 2004), and relations to the environment (Dretske 1995, chap. 5; Tye 1995, chap. 5; 2000, chap. 3; Lycan 2001). Physical states should here be understood in a broad sense that includes for example biological and functional states. 4 the two are in fact inseparable. But if this is so, how might the illusion of a merely contingent connection between the two arise? What could explain that reality presents itself to us in this distorted way? The challenge for physicalism here is that a standard way of explaining this kind of illusion seems not to be available in the present case. Consider the fact that it seems possible for rapid molecular motion to obtain without heat, even though (as it is commonly held) this is impossible since heat is molecular motion, and something can't fail to obtain without itself. In this case we can explain the illusory possibility by appealing to the idea that we are prone to confusing heat itself, the physical phenomenon, with the sensation of heat, which is the way heat appears to us. It is really possible that there could be rapid molecular motion without the sensation of heat. This real possibility together with our tendency to confuse heat itself with the way it appears to us can explain our illusory impression that there could be rapid molecular motion without heat. However, in the case of consciousness, we can't distinguish the way it really is from the way it subjectively appears; consciousness just is what it's like for a subject. Thus, when I'm under the impression that my current brain state could obtain without my current conscious state, there seems to be no other scenario (such as, the brain state without the subjective appearance of consciousness) that I plausibly confuse with this one. Therefore, if it is an illusion that consciousness and the brain are merely contingently connected, we need a different account of how this illusion arises. The knowledge argument (Jackson 1982; 1986). As illustrated by Frank Jackson's Mary, it seems in principle possible for someone to (a) know all the physical facts about colour vision, and be able to derive all that follows from these facts, while (b) not being able to figure out what it's like to see red. This might seem to show that what it's like to see red isn't reducible to physical facts – because if it were, Mary should be able to figure out what it's like to see red in virtue of knowing all the physical facts and being able to derive all that follows from them. 5 2.2 The phenomenal concept strategy: The general idea The phenomenal concept strategy is a strategy for responding to such challenges for physicalism. It is a strictly defensive strategy: it operates on the assumption that there are good reasons to accept physicalism and aims to fend off apparent reasons for rejecting it. 2 What is it to apply the phenomenal concept strategy to a given challenge to physicalism? As I understand the strategy here, it is to make the following Acknowledgment, and develop the following kind of Account of Acknowledgment: Acknowledgment: The relevant challenge brings out a way in which the reduction of conscious states to brain states is exceptional among theoretical reductions. Account: However, the exceptional character of the case can be exhaustively explained in terms of our phenomenal concepts of consciousness. What's importantly exceptional about the case are the concepts involved; not the phenomena. (Which is not to say that these concepts are in any way deficient; they are just special.) For example, the phenomenal concept strategy vis-à-vis the explanatory gap is to concede that a peculiar gap pertains to the reduction of consciousness to the brain, but offer an explanation of this in terms of our phenomenal conceptions. By the physicalist hypothesis, conscious states are physical states, and as physically conceived, they can be explained in the way typical of theoretical reductions. It is only as phenomenally conceived that they can't be so explained, but the reason for this lies entirely in the phenomenal conceptions. The approach to the appearance of contingency is similarly to acknowledge that there is a peculiar, illusory appearance of contingency about the brain-consciousness 2 Phenomenal concept theorists typically accept physicalism on the grounds that (a) some conscious states have physical effects and (b) all physical effects have complete physical causes. See for example Papineau (2002, chap. 1 and appendix), and Levine (2001, chap. 1) 6 connection – an appearance that can't be explained in terms of some real contingent connection between how the brain or consciousness really are and how they present themselves to us – but urge that this appearance arises about conscious states only as phenomenally conceived, and that it can be exhaustively explained by the character of the phenomenal conceptions. In the case of the knowledge argument, the phenomenal concept strategy is to accept that the case of consciousness allows, in a way that's exceptional among theoretical reductions, the Mary-style possibility of knowing all the physical facts without being able to figure out that it is, subjectively, the way it is to experience red. The explanation offered for this is that someone in Mary's situation would lack the phenomenal concept required to know – or even think – the relevant proposition concerning what it's like to experience red. And this is compatible with her knowing other propositions, expressible in physical terms, that concern this same fact. The resulting suggestion is that Mary's situation is like that of someone who knows that there are two things in front of her but doesn't know – for lack of the relevant concept – that the number of things in front of her is the square root of four. 2.3 Other physicalist views The phenomenal concept strategy should be distinguished from two other types of physicalist view. In the first place, Acknowledgment distinguishes the phenomenal concept strategy from what we may call nonexceptionalist physicalism. According to this view, consciousness is reducible in a way that is not in any significant way exceptional among theoretical reductions. One example of this view is a broadly applied "analytical functionalism" (Lewis 1966; 1972; 1980; Armstrong 1968). This view says that a theoretical reduction is typically accomplished by a "causal-role analysis" of some ordinary concept (for example, of liquidity as whatever it is that has suchand-such typical causes and effects), followed by an empirical discovery of which physical phenomenon in fact has those causes and effects (in this case: loose molecular bonding). Broadly applied, the view says that conscious states can be 7 similarly reduced with the help of causal-role analyses of our ordinary concepts of them. Second, the phenomenal concept strategy is distinct from what we may call lack-ofunderstanding physicalism. This view agrees that there is something exceptional about the reduction of consciousness, and that this can be accounted for in terms of our concepts or theories, but its explanation is that there is something radically missing in our current concepts or theories. The reason that the physical basis of consciousness is not perspicuous to us is, according to this view, that our concepts or theories fail to adequately capture the relevant phenomena. Varieties of this view have been proposed by Thomas Nagel (1974; 1998; 2000), Colin McGinn (1989; 2001), and Daniel Stoljar (2005; 2006). It's worth noting that, while the phenomenal concept strategy and lack-ofunderstanding physicalism agree on Acknowledgment as formulated above, there is an important underlying disagreement here. According to lack-of-understanding physicalism, there is a theory from the point of view of which the connection between the brain and consciousness is explanatory and transparently necessary in the way that the connection between, say, liquidity and loose molecular bonding is. 3 The reduction of consciousness is thus in principle "alignable" with the other theoretical reductions, whether or not we are now or ever in a position to fully grasp this. The phenomenal concept strategy, by contrast, denies that there is a theory that unifies the brain and consciousness in the way familiar from other reductions. It promises instead an explanation of why this is so. The contrasts with other views bring out some appealing characteristics of the phenomenal concept strategy. By acknowledging that the case of consciousness is exceptional among theoretical reductions the strategy pledges to take consciousness and the frequently felt puzzlement about it as seriously as anyone can ask; it thus avoids a common complaint about nonexceptionalist physicalism. In suggesting that the exceptional features of the case can be explained in terms of a difference among (non-deficient) concepts, it simultaneously promises a theoretically conservative 3 This is emphasised by Nagel (1998, sect. 7; 2000, sect. 6) and McGinn (1989, 353, 361-2; 2001, 299301 and passim). 8 account of the case; it thus avoids a common complaint about lack-of-understanding physicalism. 4 2.4 Phenomenal concepts: Varieties and commonalities What might phenomenal concepts be, that they can support the explanatory aims of the phenomenal concept strategy? The literature presents a rich flora of proposals, among them that phenomenal concepts are: (i) recognitional concept that one possesses (partly) in virtue of being able to recognise particular instances as being of the same kind (Loar 1990/1997; 2003; Tye 2000, chap. 2; 2003; Carruthers 2000; 2004; Perry 2001; Levin 2007a; 2007b); (ii) "quotational" concepts that one employs by using the very conscious state that one is thinking about (Papineau 1993, chap. 4; 2002, chap. 4; 2007; Balog 1999; forthcoming a and b; Melnyk 2002; Block 2007 draws on a similar idea); (iv) concepts that are distinguished by the special conditions under which one is justified in applying them (Sturgeon 1994; 2000, chap. 2; Hill 1997; Hill and McLaughlin 1999); (iii) indexical concepts, similar to I and now (Tye 1995, chap. 6; Lycan 1996, sect. 3.3); (v) concepts that don't just label "we know not what" but that present conscious states in a peculiarly "substantive and determinate way" (Levine 2001, 84); (vi) "conditional" concepts that refer to nonphysical states if we have appropriate states of this kind, and otherwise refer to physical states (Hawthorne 2002; Braddon-Mitchell 2003); 5 4 Of course, the phenomenal concept strategy is theoretically conservative only to the extent that its account of phenomenal concepts is. Phenomenal concept theorists typically suppose that phenomenal concepts can be accounted for in relatively familiar terms. However, Levine (2001) is a salient exception. As I read him, Levine combines (a) a phenomenal concept strategy to the problem of consciousness with (b) a lack-of-understanding physicalism about phenomenal concepts, urging that our current theoretical resources are inadequate to understanding the latter in physical terms. On the grounds for doubting that phenomenal concepts can be physically explained, see section 3.3 below. 9 (vii) concepts that utilise cognitive structures that underlie "sensory concepts", inheriting a kind of representational simplicity of the latter (Aydede and Güzeldere 2005) 7 I can't do justice, here, to the variety of ways in which phenomenal concept theorists have addressed challenges to physicalism on the basis of these proposals. I shall instead identify two ideas that are common to most or all varieties of the strategy. First, phenomenal concept theorists generally agree that phenomenal concepts – however they should exactly be understood – are inferentially isolated from physical concepts in the sense that one can't infer a phenomenal characterisation of consciousness from a purely physical characterisation, however extensive. This is to reject, among other things, the analytical functionalist view that these concepts can be analysed in terms of the typical causes and effects of their referents. This claim is a fundamental component of all phenomenal concept treatments of the explanatory gap and the appearance of contingency. It is commonly agreed that, if one could infer phenomenal characterisations of consciousness from physical characterisations of the brain, then there would be no explanatory gap or appearance of contingency between the two. To that extent, at least, the inferential isolation between the two kinds of concept explains the gap and the appearance of contingency. 8 5 Stalnaker (2002) develops a similar suggestion, but unlike Hawthorne and Braddon-Mitchell, Stalnaker suggests (251-2) that the conditional character is not distinctive of our concepts of consciousness, but pertains to concepts that we employ in other theoretical reductions as well; for example water. Since the case of consciousness is thus not claimed to be exceptional, Stalnaker's suggestion is not an instance of the phenomenal concept strategy as understood here (cf. section. 2.22.3). 7 These are proposals about what a phenomenal concept might be. But what is a concept to begin with? It is useful to distinguish at least three different uses of this term. (i) On one use, 'concept' denotes inner mental symbols that we, according to one view, use to think with (Fodor 1975; 1998). (ii) On another use, 'concept' stands for certain abstract entities, Fregean Sinne, that compose into propositions and make up what we think (for this use of the term, see Peacocke 1992; for more on Sinne, see Frege 1918/1997). (iii) On a less committal use of the term, to say that someone "employs a concept" is just to say that the person thinks something. And to say that someone possesses a concept is to say that she is able to think something. This use involves no commitment either about what we think when we think, or about what is involved in thinking (cf. Byrne 2005, sect. 1.1; Sundström forthcoming, sect. 2.4). For present purposes, we can live with this ambiguity, since one can make sense of the relevant issues on each of the three uses. 8 The phenomenal concept strategy can at this point be developed in two different ways. (1) One might claim that the inferential isolation of phenomenal concepts by itself suffices to account for the gap and appearance of contingency. This may be the view of Tye (2000; 2003); he at any rate does not appeal 10 Second, phenomenal concept theorists typically claim that phenomenal concepts are experience-dependent in the sense that, in order to possess a phenomenal concept of some conscious state S one needs to oneself have experienced S. This claim is a fundamental component of phenomenal concept treatments of the knowledge argument. If phenomenal concepts are experience-dependent, that can explain how an experience-deprived subject could know all the physical facts (physically conceived) while not knowing – for lack of the relevant concept – what it's like to see red (phenomenally conceived). 3 Worries about the strategy 3.1 Overgeneration One kind of worry – which one may have either about the strategy in general, or about some particular version of it – is that it may seem to overgenerate, in the sense of entailing false predictions about what identity or necessity claims we find troublesome. A version of this concern can be extracted from Stoljar (2005; 2006, sect. 9.6.2). Stoljar remarks (in effect) that when some peculiar feature F pertains to some concept C, F is often inherited by complex concepts that C partly constitutes. For example, if C is inferentially isolated from all concepts of a certain kind, it's plausible that the to any feature of phenomenal concepts other than inferential isolation in accounting for the gap (2000, 32-5; 2003, § 7) or for concerns around the appearance of contingency (2000, 29-32; 2003, § 5). It may also be the view of Diaz-Leon (forthcoming, sect. 3.2 and 3.4). Alternatively, (2) one might claim that the inferential isolation partly accounts for the gap and the appearance of contingency, but that something further must be identified to provide the full account. This is held by Loar (1990/1997), Levine (2001), and Papineau (2002). The motivation for this view is that there seem to be cases where (a) an identity or necessary connection is established between phenomena, and (b) our characterisations of these are inferentially isolated from one another, but where (c) we don't find any explanatory gap or appearance of contingency; at any rate, no gap or appearance of contingency that we find bothersome. This seems to be so, for example, in cases involving demonstrative reference, like "this stuff is CH3CH2OH" (cf. Loar 1990/1997, 608). 11 concept not-C is inferentially isolated from these concepts as well. Now consider the following statement: NumberNoRed: If something is a number then it's not an experience of red. We can stipulate that (i) experience of red should here be conceived phenomenally. Moreover, it seems plausible that (ii) whatever "disparity" there is between phenomenal concepts and physical concepts, there is also between phenomenal concepts and mathematical concepts. Given (i) and (ii), it would seem that: if, as the phenomenal concept strategy says, it is some disparity between phenomenal concepts and physical concepts that makes the brain-consciousness connection appear to us contingent, then NumberNoRed should also appear to us contingent. However, NumberNoRed doesn't appear to us contingent. It is, and appears necessary. Therefore, the phenomenal concept strategy seems to entail an incorrect prediction. 9 Sundström (2008) raises the same type of objection against Papineau's "quotational" phenomenal concept account of the intuition of brain-consciousness distinctness. 3.2 Conceiving consciousness as it is in itself and the threat of "deconstruction" As noted above, it seems that in the case of consciousness there is no distinction between how it subjectively appears and how it really is. Phenomenal concept theorists tend to accept this; it is part of what they typically concede to the challenge from the appearance of contingency, for example (cf. sections 2.1 and 2.2 above). Terence Horgan and John Tienson (2001) argue that the phenomenal concept strategy – or what they call "new wave materialism" – "deconstructs" under this concession. Their argument runs as follows: 9 See Diaz-Leon (2008, sect. 3) for a response to this worry. 12 1 When a phenomenal property is conceived under a phenomenal concept, this property is conceived otherwise than as a physical-functional property. 2 When a phenomenal property is conceived under a phenomenal concept, this property is conceived directly, as it is in itself. 3 If (i) a property P is conceived, under a concept C, otherwise than as a physical-functional property, and (ii) P is conceived, under C, as it is in itself, then P is not a physical-functional property. Hence, 4 Phenomenal properties are not physical-functional properties (2001, sect. 3). The argument is valid, and its conclusion contradicts physicalism. According to Horgan and Tienson, "new wave materialists are committed to premises 1 and 2". They can therefore contest only premise 3. Their problem, however, is that 3 "seems virtually tautologous" (2001, sect. 3). 11 I suspect that Horgan and Tienson are only partly right about where new wave materialists or phenomenal concept theorists may contest the deconstructive argument. 12 I believe there is a crucial disagreement about the interpretation under which premise 2 is correct, and that this disagreement underlies any disagreement about 3. It is true that phenomenal concept theorists tend to accept wordings like that of premise 2. For example, Brian Loar says that a phenomenal concept picks out its referent "directly and essentially" (1990/1997, 600). Katalin Balog says that phenomenal concepts "provide a grasp of the phenomenal properties in a way that reveals their essence" (forthcoming b, sect. 2). And Brian McLaughlin, in a response 11 Goff (forthcoming) develops a similar objection to the phenomenal concept strategy. 12 There is room for discussion about whether "new wave materialism", as Horgan and Tienson understand it, is exactly the same as or slightly different from the "phenomenal concept strategy" as understood here. For present purposes we can disregard most of the (potential) differences between the views. But one should note that Horgan and Tienson's argument targets strategies for defending identity physicalism specifically. Due to limitations in space, I can't here discuss how the argument might be extended to challenge the view that brain states and conscious states are (merely) necessarily connected. 13 to Horgan and Tienson's argument, concedes that: "New wave materialists ... embrace premise 2: it is one of the central tenets of their view" (2001, 324). However, it turns out that Loar, Balog, and McLaughlin all have serious reservations about the sense in which our phenomenal conceptions "reveal the essences" of phenomenal properties. McLaughlin urges that phenomenal concepts "do not conceptually reveal anything about the essential nature of phenomenal properties: they simply name or demonstrate them" (2001, 324), and that phenomenal concepts "present phenomenal properties only in the sense that they directly refer to phenomenal properties (2001, 328). Loar distinguishes two different uses of 'capture the essence of': On one use, it expresses a referential notion that comes to no more than 'directly rigidly designate'. On the other, it means something like 'be conceptually interderivable with some theoretical predicate that reveal the internal structure of the designated property'" (1990/1997, 603). Loar only ever acknowledges that phenomenal concepts "capture the essence" of phenomenal qualities in the former sense (see, e.g., 608-9). And Balog states that phenomenal concepts "will not afford any clue as to the fundamental nature of the referent". While they "afford an insight into the essence of the referent", the sense in which they do so is "by exemplification"; i.e., in the sense that phenomenal concepts use phenomenal properties to think about phenomenal properties (forthcoming b, sect. 2). Given these reservations, it is not clear that Loar, McLaughlin and Balog accept that we conceive phenomenal properties "as they are in themselves" in the sense that Horgan and Tienson intend in premise 2. Horgan and Tienson have in mind, I believe, something like an insight into, or understanding of the essential nature of phenomenal properties. But to say that we refer to phenomenal properties "directly" or "rigidly" or "by exemplification" is not to accept any such thing. We can plausibly (a) refer to something directly or rigidly or by exemplification while (b) lacking insight into the essential nature of what we refer to. Consider for example a set of differently shaped cardboards attached to sticks. I may lift one of the cardboards by 14 its stick without looking at it and say, "now look at this (type of) shape". It is plausible, I think, that I can in this case refer directly, and rigidly, and by exemplification to a type of shape while having little insight into its essential nature. It seems natural to interpret Loar's, McLaughlin's and Balog's reservations about the "essence revealing" character of phenomenal concepts, and their emphases instead on "directness", "rigidity" and "exemplification", as nods towards some such model for understanding how we grasp conscious states under phenomenal concepts. 13 This dispute concerning premise 2 underlies, I think, any disagreement concerning premise 3, which says, to repeat: 3. If (i) a property P is conceived, under a concept C, otherwise than as a physical-functional property, and (ii) P is conceived, under C, as it is in itself, then P is not a physical-functional property. If our phenomenal conceptions should display phenomenal properties "as they are in themselves" in the sense that Horgan and Tienson are after, this might well be "virtually tautologous". But if phenomenal conceptions display phenomenal properties "as they are in themselves" only in the sense that Loar, McLaughlin and Balog grant, there may be little reason to accept 3. At any rate, to the extent that phenomenal concept reference should be modelled on the kind of "directness", "rigidity" or "exemplification" illustrated by the cardboard case, there seems to be little reason to accept it. It seems that I can in this case refer to a certain shape directly, rigidly and by exemplification, and conceive it "otherwise than as" three- 13 The model may be imperfect. In the cardboard case, the direct, rigid, and exemplificatory reference is to a high degree "cognitively blind"; I just refer to whatever shape it is that I in fact display. Meanwhile, Loar, McLaughlin, and Balog emphasise that phenomenal concept reference involves a "substantive", or "non-blind", or "non-naked" mode of presentation of conscious states (Loar 1990/1997, sect. 4-5; McLaughlin 2001, 326; Balog forthcoming b, sect. 2). But if that's the idea, there may be no close analogies from other cases to appeal to. It is not easy (for me) to think of a case such that: (a) I have a "non-blind" grasp of some property, and (b) this property is grasped as it is in itself (rather than in terms of some contingent, superficial appearance), while (c) I nonetheless lack the kind of insight into the essential nature of the property that Horgan and Tienson appear to be after in premise 2. Loar, McLaughlin and Balog may well suppose – or be committed to supposing – that phenomenal concept reference uniquely exemplifies (a)-(c). For an argument that phenomenal concept theorists should construe phenomenal concept reference as "cognitively blind", see Levin (2008). Hawthorne (2002, 44-5) may perhaps be read as suggesting this as well. 15 sided, in the argument's intended sense; 14 but for all that, three-sidedness may be part of the essence of the shape referred to. We may note in passing that Horgan and Tienson's argument in effect illustrates the above mentioned idea of invoking phenomenal concepts to defend dualism. While presented as an ad hominem argument against "new wave materialists", whom Horgan and Tienson portray as wedded to premises 1 and 2, one might promote the argument and its anti-physicalist conclusion as plausible independently of new wave materialist commitments. A dualist argument in this spirit is developed by Nida-Rümelin (2007). As both Horgan and Tienson, and Nida-Rümelin note, their arguments are similar to other influential arguments for dualism, such as Kripke's (1972/1980) "modal argument", Chalmers' (1996; 2010) "two-dimensional argument", and the "property dualism argument" (White 1986; 2007; see also Smart 1959, 148-50). 3.3 Are phenomenal concepts themselves physically explicable? The phenomenal concept strategy aims to show that concerns about the physical nature of consciousness can be explained in terms of phenomenal concepts. But what about the phenomenal concepts themselves: can we give a satisfactory account of their nature in physical terms? Joseph Levine (2001; 2007) argues that phenomenal concepts provide us with a peculiarly thick and substantive mode of presentation of conscious experiences, and that we presently lack the resources to understand how this kind of representation could be physically realised. A physicalist is according to Levine confined to explain representation in terms of causal and nomological notions. And it seems hopeless to explain the kind of access that we have to our conscious experiences in these terms. David Chalmers (2007) provides a related "master argument" against all varieties of the phenomenal concept strategy. The conclusion aimed for is: 14 Of course, I don't in this case conceive the shape as not three-sided. But I conceive it and I don't conceive it as three-sided. And that suffices, it seems, for conceiving it "otherwise than as three sided" 16 Chalmers' Conclusion: Phenomenal concepts are bound to be characterised either (i) so "thinly" that they fail to account for our "epistemic situation" with regard to consciousness, or (ii) so "thickly" that they can't be explained in physical terms. The argument is developed around the question whether it is coherently conceivable that there be physical duplicates of us that lack our phenomenal concepts. If this is coherently conceivable, then, Chalmers argues, phenomenal concepts are not physically explicable; they themselves generate the kind of explanatory gap they were supposed to explain (sect. 3.1). Suppose on the other hand that it is not coherently conceivable that physical duplicates of us lack phenomenal concepts. That would be to say that zombies (physical duplicates of us without consciousness) are guaranteed to have whatever phenomenal concepts we have. But, Chalmers argues, zombies are not in the kind of epistemic situation that we are in with regard to consciousness. For example, when zombie-Mary leaves her black-and-white room, she does not gain knowledge that is as "cognitively significant" as the knowledge that conscious Mary acquires in the corresponding situation. Therefore, on this supposition, phenomenal concepts don't explain our epistemic situation with regard to consciousness (sect. 3.2). Responses to Chalmers' argument have typically in one way or other developed the following idea. By the physicalist hypothesis, conscious states as well as our phenomenal conceivings of conscious states are physical phenomena. And, just as we can conceive of our conscious states in both phenomenal and nonphenomenal ways, so we can conceive of our phenomenal conceivings in these two ways. As an instance of this, Chalmers' Conclusion can be read in two ways, depending on whether it employs a phenomenal or a nonphenomenal concept of phenomenal concepts. One way to develop this idea is to urge that Chalmer's Conclusion is false if phenomenal concepts are physically conceived. Physically conceived, phenomenal concepts can be physically explained. But they can also explain our epistemic situation, according to this suggestion. Although zombie-Mary has no conscious in Horgan and Tienson's sense. They stress that conceiving of a property "otherwise than as" so-and-so is "different from, and weaker than" conceiving it "as otherwise than" so-and-so (note 4). 17 experience, she acquires on release from her confinement concepts that are novel to her to a degree that parallels Jackson's Mary (see Carruthers and Veillet 2007; Papineau 2007, sect. 5.4; Levin 2008, sect. 2). Another response, developed by Balog (forthcoming b), urges that Chalmers' Conclusion is true but harmless for the phenomenal concept strategy on both the phenomenal and the nonphenomenal reading. Chalmers' Conclusion is true if phenomenal concepts are physically conceived because, while phenomenal concepts thus conceived can be physically explained, they don't explain our epistemic situation. But this is something that a phenomenal concept theorist "should insist" on (sect. 3). Chalmers' Conclusion is true if phenomenal concepts are phenomenally conceived because, while phenomenal concepts thus conceived explain our epistemic situation, they can't be physically explained. But this new explanatory gap – between physical facts (physically conceived) and phenomenal concepts (phenomenally conceived) – "doesn't pose a challenge to the physicalist over and above the original explanatory gap" (ibid.). Diaz-Leon (forthcoming) also suggests that Chalmers' Conclusion is, even if true, harmless for the phenomenal concept strategy. A phenomenal concept theorist need not, she argues, account for our "whole epistemic situation" with regard to consciousness, but only for the "inferential disconnection" between physical and phenomenal concepts (sect. 3.2). 4 First-person psychology and epistemology Besides being invoked to defend physicalism or dualism, phenomenal concepts have been invoked, by both physicalists and dualists, to explain psychological and epistemic phenomena such as: (a) our peculiar direct acquaintance with our own consciousness; (b) the fact that we seem to gain knowledge about our own consciousness in ways not accessible from a third-person perspective; 18 (c) the fact that we seem to be infallible or incorrigible about some judgments about our own consciousness; for example, judgments that one would naturally express in terms like, "I have this kind of experience right now". Balog (forthcoming a, sects. 3-4) offers an explanation of such phenomena based on the "constitutional account" according to which phenomenal concepts use phenomenal properties to refer to phenomenal properties. Chalmers (2003, sect. 4.1) draws on a similar account to justify an incorrigibility thesis according to which a certain class of phenomenal beliefs can't be false. 15 The merits of these accounts can't be discussed here. However, it is worth noting that, contrary to what is sometimes suggested, 16 it is not apparent that phenomena like (a)- (c) should be explained in terms of phenomenal concepts, or in terms of concepts at all. Another possibility is that they should be explained by some non-concept involving access, like an inner experience, on the basis of which we apply concepts to our conscious states. 17 5 So, do we possess phenomenal concepts of our conscious states? So, do we possess phenomenal concepts of our conscious states? Whether we should say so depends, of course, on what we mean by 'phenomenal concept'. On a broad understanding, a concept is phenomenal if and only if it concerns a conscious state. It is relatively uncontroversial that we possess phenomenal concepts in this sense. 18 15 See also Papineau (2002, sect. 4.12) for a similar suggestion. 16 See, e.g., Balog (2009, 299). 17 This is analogous to the proposal that our access to our outer environment is established by nonconcept involving perceptions, on the basis of which we apply concepts. For general overviews of such "conceptualist" versus "nonconceptualist" debates, see Toribio (2007) and Bermúdez and Cahen (2008). Gunther (2003) is an important collection of texts. 18 Exactly how controversial it is depends on what one means by 'concept'; cf. note 7 above. 19 But as we have seen, philosophers typically mean something more specific than this by 'phenomenal concept': the term is strongly associated with the idea that we possess concepts of our conscious states that are in one way or other very special, or even unique. We have encountered several proposals about what this specialness might consist in. Three important suggestions are that these concepts: (i) are inferentially isolated from physical concepts; (ii) are experience-dependent, in the sense that, to have a concept of a type of conscious state S, one needs oneself to have experienced S; (iii) provide us with a grasp of what conscious states are in themselves. It should be recognised, I believe, both that (i)-(iii) are all controversial, and that it's controversial whether either one entails that the relevant concepts are unique. I will conclude by summarising and discussing the suggestions, in a somewhat reshuffled order. Regarding the suggestion (i) that we possess concepts of consciousness that are inferentially isolated from physical concepts, this is disputed by at least some "analytical functionalists" (cf. section 2.3). But even supposing it is true, it is hard to see that this would make the relevant concepts unique. As several phenomenal concept theorists have pointed out, indexical and demonstrative concepts are plausibly inferentially isolated from physical concepts as well, and the same may be true of, say, natural kind concepts like water and heat (Loar 1990/1997, 608; Levine 2001, 823, and sect. 2.4-2.5). Regarding the suggestion (iii) that the relevant concepts provide us with a grasp of what consciousness is in itself, I have suggested that verbal agreements over such phrases often hide substantive disagreements. Some take this to mean that phenomenal concepts provide us with something like an insight into the essence of consciousness. Others, it seems, take it to mean only that phenomenal concepts refer to conscious states directly or rigidly, or that their uses exemplify consciousness. On either of these interpretations of (iii), it is again doubtful that, if true, it would make phenomenal concepts unique. We plausibly refer directly and rigidly by means 20 of proper names and demonstratives, 19 and by exemplification when we use quoted words to refer to words. It may also be plausible that we have theoretical concepts – like an educated person's concept of electron – that amount to insights into the essences of what we conceive. The same might be true of many mundane concepts, like sofa or friend. The experience-dependence claim, (ii), is also controversial. A long-standing objection to this kind of claim draws on the possibility of certain "duplication" scenarios. Take the physical state that I was in last night as I fell asleep in the dark. It is in principle possible that a molecule-for-molecule copy of me in that state should be created, by design or accident, out of "nothing". The result would be a creature that had never experienced any colour. But it seems plausible that the creature would possess any concepts that I possess of what it's like to experience colours (Unger 1966; Dennett 2005, chap. 5). This objection targets theses to the effect that it is absolutely impossible to have to relevant kind of concept without the relevant kind of experience. It doesn't threaten nomological theses, like the claim that this kind of concept-acquisition is ruled out by the psychological laws of normal human development. 20 But we should recognise this "anthropological" experience-dependence thesis to be controversial as well. Analytical functionalists can contest it on the grounds that causal role concepts can plausibly in general be acquired in ways other than by experience. Another recent challenge comes from (overlapping) arguments by Michael Tye (2009, sect. 3.6) and Derek Ball (2009). 21 Tye and Ball argue that our concepts of consciousness can be possessed even if one only "partially understands" them, and that one can therefore acquire them from others even if one has not been in the states they concern. 22 19 Cf. Kripke (1972/1980), and Kaplan (1989). 20 Compare: Duplication possibilities may show that it is in principle possible to become a passable speaker of Japanese without being exposed to Japanese. But it still seems to be a reliable, law-like, psychological generalisation that all speakers of Japanese have been exposed to Japanese. 21 Tye is of course a former phenomenal concept theorist, but has turned into a critic in his 2009 book. 21 A further challenge to the anthropological experience-dependence view comes from Hume's missing shade of blue. If you experience a wide enough range of colours, that plausibly suffices to acquire any concept of light blue that I possess, even if you haven't experienced light blue in particular. Indeed, this may be how we typically, in fact acquire our concepts of sensory states: given a varied enough sample we "fill in" the rest. If so, it is not the case, even as an anthropological matter, that you must have been in conscious state S to have a phenomenal concept of S. 23 Finally, even if (ii) should be true – either as an absolute or an anthropological matter – there is again room for doubt that this would make phenomenal concepts of consciousness unique. Insofar as it's plausible that we have concepts of conscious states that require having experienced these states, something analogous may well be plausible for certain (demonstrative, or "perceptual") concepts of features of our environment. 24 So, as often in philosophy, there is little uncontroversial ground to occupy in the territory around "phenomenal concepts". 25 References Armstrong, David. 1968. A Materialist Theory of the Mind. London: Routledge. Aydede, Murat, and Güven Güzeldere. 2005. Cognitive architecture, concepts, and introspection: An information-theoretic solution to the problem of phenomenal consciousness. Noûs 39, no. 2: 197-255. 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