Russellian Physicalism, Bare Structure, and Swapped Inscrutables Kevin Morris Published version in The Journal of Consciousness Studies 23, 9-10, 2016, pp. 180-198. (here) Abstract This paper discusses and evaluates a recent argument for the conclusion that an attractive variety of Russellian monism ought to be regarded as a form of physicalism. According to this line of thought, if the Russellian's "inscrutable" properties are held to ground not only experience, but also the physical structure of the world-and in this sense are not "experience-specific"-they thereby have an unproblematic place in physicalist metaphysics. I argue, in contrast, that there can be a sense in which the Russellian's inscrutables are experience-specific in a way that a physicalist probably ought to find objectionable, even if they play some role other than grounding experience. This will be the case, I argue, if certain worlds are taken to be possible, as they sometimes have: worlds of "bare structure" and worlds with what might be called "swapped inscrutables". In this way, I claim that accepting certain possibilities has consequences for how one should understand the nature of the Russellian's inscrutables and the place they have in physicalist metaphysics. 1. Introduction: From Russellian Monism to Russellian Physicalism Russellian monism has rightfully attracted considerable attention in recent metaphysics of mind. Often, the motivation has been the thought that a Russellian view can capture what is right about standard forms of physicalism and dualism, but without suffering the perceived shortcomings of either.1 While Russellian views can be spelled out in a variety of ways,2 the version here of interest involves several core ideas. First, it supposes that experience in humans and other organisms is somehow grounded in what David Chalmers (2015) calls "protophenomenal properties" or what Barbara Montero (2010) calls "inscrutables": intrinsic (or "categorical" or "qualitative") aspects of our basic constituents that, while not themselves phenomenal or experiential, ground experience in humans and other organisms. Second, it supposes that these very same properties also ground the dispositional and relational aspects 1 See Chalmers 2015 and Stoljar 2001. It is a matter of dispute to what extent the view here described is properly attributed to Russell; see Lockwood 1981, Ney 2015, and Wishon 2015. For discussions from Russell, see Russell 1927 and 1956. 2 See Chalmers 2015 and forthcoming; see also Alter and Nagasawa 2012. 2 of our basic constituents and, ultimately, all of reality as described by physics.3 In this sense, the Russellianism of interest aims to deny that the inscrutables are purely "protophenomenal". Thus Montero (2010, 77) writes that on Russellianism so understood, such properties are held to ground "the entire concrete world, only a very small portion of which is mental". As Chalmers emphasizes, this dual role for the inscrutables is a potentially significant theoretical benefit, as it promises to solve two apparent problems-the grounding of experience and the grounding of the dispositional and relational character of the world-with a single posit.4 Third and finally, it supposes that while physics is in the business of describing these dispositional and relational aspects-the "structure" of the world- physics fails to adequately capture the intrinsic ground for this structure, that is, the inscrutables. This, it has been claimed, explains the pull of well-known arguments against physicalism and the plausibility of the view that purely physical facts do not account for experience. According to the Russellian, the plausibility of these arguments can be explained by the fact that experience is grounded in the inscrutables, which are not captured by the conceptual and representational resources of physical theory.5 Now, Russellianism is often introduced as an alternative to physicalism in the metaphysics of mind. And in certain senses of "physicalism", this is certainly the case. For example, the Russellian denies that physical theory provides an exhaustive and complete description of reality. Russellianism is thus inconsistent with physicalism if "physicalism" is defined as the thesis that physics provides an 3 Much of the discussion of Russellianism has used "dispositional", "relational", "structural", and "extrinsic" more or less interchangeably; likewise for "intrinsic", "qualitative", and "categorical" (as noted in Alter and Nagasawa 2012, 72-73). These are not equivalent notions, however. For example, dispositions are not relations (see Heil 2003). Nonetheless, I do not believe that the success of my arguments turns on exactly how these notions are sorted out. Montero (2010, 74) refers to the Russellian's basic properties as "inscrutables" in part because of dissatisfaction with the aforementioned distinctions. 4 Chalmers (1996 and 2015) extracts this from Russell 1927. Even those critical of Russellianism have recognized this as an important potential benefit. Ney 2015, for example, goes so far as to compare it with Newton's unification of terrestrial and cosmic reality. While a thorough discussion of the merits of different ways of explicating Russellianism is beyond the scope of this paper, a concern about taking the inscrutables to only ground experience is that this threatens to leave obscure the relationship between the inscrutables on one hand and the relational and dispositional (and so, for the Russellian, physical) aspects of the world on the other. And it is because of this that a Russellian view so explicated may succumb to worries similar to those thought to beset explicitly dualistic views. See Chalmers 2015 and Howell 2014 for related discussion. 5 See Chalmers 2015 and Stoljar 2001. 3 exhaustive and complete description of reality.6 Nonetheless, there may be reasons to think that some varieties of Russellianism ought to be regarded as physicalist outlooks. This is comparable to how it has often been thought that a view may be properly regarded as physicalistic even if it denies that all properties that are instantiated are strictly identical with the properties described by physics, so long as it maintains that any such properties are in some way realized or determined by the properties described by physics. The result is "nonreductive physicalism" in its myriad forms. And Montero argues that when Russellianism articulated in the manner just sketched, there is no reason why it should not be regarded as a form of physicalism-that there is nothing in such an outlook that a physicalist ought to find objectionable. First, she claims (2010, 79) that whether a property should count as nonphysical is a matter of whether it suggests that the world was "created with us in mind" or (2010, 71) that "mentality received special consideration in the creation of the universe". That is, Why should certain properties, such as fundamental properties that are mental count as nonphysical? I think that certain properties have been deemed physically unacceptable because they hint at a world that was created with us in mind. If mental phenomena were fundamental, being, for example, part of the original brew that was set in motion in the big bang or as emerging as something extra along the way, mentality would have a place of prominence in the world.7 Metaphors aside, the idea appears to be that fundamental properties that are experience-specific have a dubious place in a robustly physicalist picture. Montero (2010, 77) notes, for example, that typical nonreductive physicalist views do not suppose that there are fundamental properties needed specifically to underlie experience. Rather, typical nonreductive views suppose that "the fundamental physical world is the dependence base for everything including consciousness" and thus that mentality did not receive "special consideration" in the creation of the universe. 6 This is essentially the thesis that Galen Strawson (2006) refers to as "physicSalism". 7 Montero 2010, 79. See Montero 2013 and 2015 for related discussion. 4 Given these considerations, if the sole role for the inscrutables in the actual world were to underlie experience, it would have to be concluded that such properties have no place in a genuinely physicalist outlook. At best, a view that posits such properties would be a "borderline case of physicalism" (2010, 77). However, when Russellianism is developed in the recommended way, it seems false that the inscrutables are "for the sole purpose of generating consciousness" (2010, 71), since in addition to grounding experience, they also ground physical structure. Therefore, Montero concludes that on the Russellianism of interest, while the inscrutables are not "accountable for by physics", they are nonetheless "physicalistically acceptable". She thus concludes that Russellianism so understood is "physicalistic through and through" (2010, 71), a "full-blooded form of physicalism" (2015). Hence, she maintains (2010, 2015) that insofar as familiar arguments against physicalism do not rule against this form of Russellianism, they fail to refute physicalism. There are, I believe, several merits to Montero's case. For one thing, I agree with her (2010, 77) that even if the Russellian's inscrutables are not themselves experiential, they have no place in a physicalist outlook if they are purely protophenomenal. Further, I agree that "physical" does not mean "being accountable for by physics". Following Montero and others,8 I believe that proposals along these lines make the metaphysical thesis of physicalism depend on issues that are ultimately epistemic and representational. Finally, I agree with her underlying assumption that it is worth getting clear on how Russellian views are related to more familiar approaches (in contemporary analytic philosophy, at least) for understanding the place of mind in nature, and in this way better articulating the conceptual landscape of the metaphysics of mind. I also believe, however, that there are reasons to think that the route from Russellian monism to physicalism is less straightforward than Montero supposes. Specifically, I believe that insofar as one 8 See Montero 2010, 79 and Howell 2013, Chapter 1. See also Strawson 2006. 5 aims to vindicate the physicalist credentials of Russellianism in the manner that Montero pursues,9 one probably ought to deny the possibility of "bare structure" (worlds with the same dispositional and relational character as the actual world, but with no inscrutables grounding that structure) as well as the possibility of what might be called "swapped inscrutables" (worlds with the same dispositional and relational character as the actual world, but with a different distribution of experience-including worlds without any experience-in virtue of instantiating different inscrutables). If these possibilities are countenanced, as they often have been, there is some reason to doubt that the Russellian's inscrutables have a clear and unambiguous place in physicalist metaphysics, even if they do more than just ground experience in organisms. In other words, if these possibilities are accepted, there is some reason to doubt that Russellianism in the sense of interest is "physicalistic through and through". I will argue for these claims in Section 2, and will briefly explore some related issues in Section 3. 2. Bare Structure and Swapped Inscrutables The line of thought that I would like to pursue can be introduced by way of the following passage due to Montero (2010, 78), though the ideas here are not uncommon in the literature: Russellian physicalism is consistent with the failure of upward determination of10 physics since it holds that duplicating just the fundamental physics of our world, which we are assuming is entirely structural, duplicates only more structure and not consciousness. If Russellian physicalism were true, a world that duplicates our fundamental physics yet lacks consciousness would either have inscrutables that 9 See Pereboom 2011 for an alternative strategy for moving from Russellianism to physicalism. While I will not be discussing Pereboom's approach, it may be contrasted with Montero's as follows. Pereboom and Montero agree that whether Russellianism is a form of physicalism turns on whether the inscrutables are "physicalistically acceptable". For Montero, this is a matter of what these properties do-whether they ground something other than experience. For Pereboom, in contrast, this is a matter of how these properties are in themselves-for example, whether they can be understood in terms of prime materiality or perfect solidity, or in some other way as nonmental and sufficiently similar to the paradigmatic properties of physics. 10 It would seem that "of" should read "from". The issue here, it seems, is whether physics "upwardly fixes" facts about experience and consciousness. Physics, the Russellian holds, is itself determined by the inscrutables; hence, the Russellian insists on the "upward determination of physics"-namely, the "upward determination" of physics from the inscrutables. 6 differ from those in our world and do not ground consciousness or, perhaps, no inscrutables at all. The idea here is something like this. First, duplicating the purely physical aspects of the world-the world as described by physics-amounts to merely duplicating its dispositional and relational character, its "structure". Mere structure, the line of thought goes, does not suffice for experience or consciousness; as noted in Section 1, this might be utilized to explain the intuitive pull of familiar arguments against physicalism. Second, however, it is held that for a world to duplicate the actual world physically yet differ experientially, it must have different inscrutables, or have no inscrutables. Such a world must either have inscrutables that might be said to be "swapped" with those of the actual world, or be a world of "bare structure". On the one hand, then, it is held that the inscrutables in the actual world fix or determine the relational and dispositional character of our world, at least in that duplicating the inscrutables that are instantiated in our world, and nothing else, suffices to duplicate the relational and dispositional character of our world and, indeed, the entire world as described by physics. On the other hand, however, on the present picture there is a kind of looseness between the inscrutables and the structure of the world. First, it is possible for there to be the same physical structure, but without any inscrutables ("bare structure"); second, it is possible for there to be the same structure, but grounded in different inscrutables ("swapped inscrutables"). What is not clear to me is whether countenancing these possibilities fits well with the idea that the inscrutables said to be instantiated in the actual world have a clear place in physicalist metaphysics. I will first attempt to bring out the way in which, if these possibilities are granted, there is a sense in which the inscrutables are experience-specific, even if they ground physical structure. I will then argue that given the sense in which the inscrutables are experience-specific, they probably do not have a place in physicalist metaphysics. That is, I will argue that a view that posits properties like these probably cannot be regarded as a "full-blooded form of physicalism". 7 Consider, first, the possibility of "bare structure"-a world in which the fundamental constituents have the very same relational and dispositional nature as the fundamental constituents of the actual word, but with nothing grounding this relational and dispositional character. Generally, such a world is claimed to be structurally just like the actual world, and thus for the Russellian just like the actual world as described by physics. It is just that there is nothing grounding this structure. Accepting this as a genuine possibility seems to have consequences for how one should think about the nature of the inscrutables that the Russellian claims are instantiated in the actual world. Specifically, accepting the possibility of bare structure raises the issue of why, exactly, these inscrutables should be needed at all. After all, if the possibility of bare structure is accepted, it would seem that the inscrutables said to be instantiated in the actual world are not needed to ground the physical structure of the world, since this structure could exist just as it is without any inscrutables. Rather, it would seem that if the structure of the world could exist as it is ungrounded, the inscrutables are needed specifically to ground experience in the actual world, and that it is in this capacity that they differentiate our world from the world of bare structure. This can be expressed in terms of a creation metaphor. If worlds of bare structure are possible, why should God have created the inscrutables that are instantiated in the actual world? If worlds of bare physical structure are possible, God did not need to create the inscrutables in order to create the entire dispositional and relational character of the world, which for the Russellian is the whole world as described by physics. Rather, the answer appears to be experience-relevance: God created a world with the inscrutables because without them the world would be devoid of experience. In this sense, if worlds of bare structure are possible, the inscrutables in the actual world are experience-specific, despite grounding the structure of the world: the "sole purpose" of these properties is not to ground experience, but it is in this capacity that such properties are needed. When 8 it comes to grounding the physical character of the word, such properties would seem dispensable, as the world could be physically just as it is without anything playing this role.11 Now, the possibility of bare physical structure may not be of much concern. For one thing, while Montero (2010, fn.5) notes that some have claimed that the actual world is a purely structural world, it is doubtful that a Russellian should be happy with this. After all, a Russellian will typically wish to deny that a world of pure structure could include experience. But there is experience in our world. Moreover, the possibility of bare structure threatens to undermine the force of the claim to provide a single ground for both physical and experiential reality-accepting such a possibility would amount to conceding that the world as described by physics does not need some further ground. Because of this, a Russellian who accepts the possibility of bare structure might be best served to hold that the inscrutables in the actual world are solely for the purpose of grounding experience. As noted above, it is doubtful that Russellianism so articulated can be regarded as a variety of physicalism. Finally, while some have argued for the coherence of a purely structural world,12 this is a highly contentious issue, independently of Russellianism.13 In any case, those attracted to Russellianism will be less likely to dismiss the possibility of "swapped inscrutables". Further, the manner in which the possibility of "swapped inscrutables" suggests that the Russellian's inscrutables may prove to be experience-specific is more transparent and 11 It might be held that even if the possibility of bare structure is accepted, there is nonetheless a sense in which the physical structure of the actual world requires the inscrutables that the Russellian claims are actually instantiated (this issue was raised by an anonymous referee at this journal).It is not easy to see, however, in what sense this could be both true and significant. On a straightforward reading of the claim that worlds of bare structure are possible, it follows that the structure of the world could exist as it is without any further ground, and thus that the structure of the world does not require grounding in the inscrutables that are actually instantiated. It may be possible to vary the strength of the modalities here so as to yield the result that (a) the possibility of bare structure and (b) the claim that the physical structure of the actual world could not exist without being grounded in the actual inscrutables are consistent. Perhaps this will be the case if the modality in (a) in logical or metaphysical while the modality in (b) is less than logical or metaphysical. However, the challenge would then be say exactly why this fact, if it is a fact, should bear on the force of the arguments that I advance. My assumption, in any case, is that the relevant modality is logical or metaphysical throughout. Related remarks apply to the possibility of "swapped inscrutables". 12 See Ladyman, Ross, et. al. 2007. 13 For criticisms of the very notion of a purely structural or relational world, see Heil 2012 and Unger 1998. Montero appears to be ambivalent here. She reports (2010, fn. 5) that she is not sure whether such a world is possible. However, in offering a Russellian response to familiar arguments against physicalism, she appears to suppose that worlds of bare structure are genuinely possible, and that this may be what is being conceived when one conceives of physical sameness as the actual world with experiential difference (see Montero 2015 and Montero 2010, 78). 9 more forceful than in the case of bare structure. Consider, then, a world with "swapped inscrutables". In particular, consider a world that has the same dispositional and relational character as the actual world, but with a different distribution of experience-indeed, completely lacking in experience-in virtue of instantiating different inscrutables. If this possibility is accepted, it should be asked: what, exactly, is the difference between the inscrutables in this world, and those that the Russellian claims are instantiated in the actual world? They both ground physical structure. The difference, rather, appears to be that the actual inscrutables also ground experience. This, it would seem, is the distinctive contribution that they make to the nature of the world, and it is in virtue of this experience-grounding role that our world has a very different character than the world with "swapped inscrutables". It is this role that distinguishes the inscrutables in the actual world from those in the world with grounded physical structure but lacking in experience. When it comes to the role that they play in grounding the world and its character, it is this experience-grounding role that is individuative, in that it is what distinguishes these properties from the inscrutables that ground physical structure but fail to ground experience. It will be helpful to compare the present line of thought with Robert Howell's (2009) recent discussion of emergentism and supervenience. Howell asks whether it is coherent to suppose, as some have, that truly novel and irreducible "emergent" properties metaphysically supervene on purely physical properties. He claims, not implausibly, that properties that are necessarily disposed to give rise to truly novel and irreducible "emergent" properties can hardly be said to be purely physical properties. On this basis, he concludes that an emergentist cannot, in fact, suppose that truly novel and irreducible "emergent" properties supervene with metaphysical necessity on purely physical properties. While I will not engage with the details of Howell's argument,14 he presents the following as an intuitive gloss (2009, 93-94): 14 I have done so elsewhere; see Morris 2014. 10 ... suppose we found out that our world had schmairs in it. Schmairs are just like chairs, except that when zombies sit in them they are suddenly conscious. This is just a brute disposition of schmairs. To my mind, the existence of schmairs in our world clearly suggests that the fundamental furniture of our world is not exhaustively describable as physical. Schmairs might not themselves be conscious, but a fundamental, irreducible part of what makes them what they are is the disposition to confer consciousness... Howell goes on to argue, much like I will below, that if the basic constituents of our world similarly have brute, necessary nonphysical dispositions, the right conclusion to draw is that "a sort of quasipanpsychism" is true. At this point, however, my more modest point is that if the possibility of "swapped inscrutables" is taken on board, the inscrutables that the Russellian claims are instantiated in the actual world appear to be much like Howell's schmairs. In particular, both schmairs and the inscrutables are individuated, in part, in terms of experience-relevance. This is what distinguishes schmairs from chairs, and it is what distinguishes the inscrutables in our world from the inscrutables in worlds with grounded physical structure but lacking in experience. In both cases, moreover, crossworld comparisons are brought to bear on understanding the nature of the items in question. The possibility of chairs, as distinct from schmairs, mandates recognizing that part of what makes schmairs what they are is experience-relevance. Likewise, the possibility of inscrutables that ground physical structure, but not experience, appears to mandate recognizing that part of what makes the inscrutables in our world the properties that they are is experience-relevance. In this sense, if the possibility of "swapped inscrutables" is accepted, the Russellian's inscrutables appear, like schmairs, to be experience-specific, even if they do more than just ground experience. Below I will consider whether properties that are experience-specific in this sense have a place in physicalist metaphysics. As with the possibility of bare structure, a creation metaphor may be helpful. If worlds with "swapped inscrutables" are possible, God could have created other inscrutables to ground the structure of the world. So, why should God have used the inscrutables of interest, rather than some others, in 11 creating our world? Again, the answer appears to be experience-relevance: the actual inscrutables are needed to ground experience in humans and other organisms. This is comparable to how, if chairs are just like schmairs except when it comes to experience-relevance, it would be wise for God to create the world using schmairs rather than chairs if God's aim is to create a world that contains the dispositional features associated with chairs but moreover has select pockets of additional experience. In this way, if worlds with "swapped inscrutables" are possible, it seems that there is a sense in which "mentality received special consideration in the creation of the universe", even if the inscrutables in the actual world do more than just ground experience. If these remarks are on track, even if the Russellian's inscrutables are not purely protophenomenal, it may be that what is distinctive and perhaps individuative of them is that they are protophenomenal, and that it is in this capacity that they are needed to make our world the kind of world that it is. Do properties like this have a place in physicalist metaphysics? Are they "physicalistically acceptable"? Can a view that includes such properties be properly regarded as "physicalistic through and though"? This question is difficult to answer, and to some extent may be a matter of stipulation. But what can be said is that such properties appear, in certain relevant respects, to be akin to purely protophenomenal properties and unlike the properties in standard forms of physicalism. In certain relevant respects, they are more like schmairs than chairs. Because of this, a view that posits such properties is probably at best regarded as a "borderline case of physicalism". There are at least three related reasons for thinking that this is the case. First, when it comes to making our world the kind of world that it is, both purely protophenomenal properties and the inscrutables of interest are needed in virtue of the role that they play vis-à-vis experience. This can be brought out by noting that insofar as such properties are posited on the grounds that they are needed to explain the character of the world, both purely protophenomenal properties and the Russellian's inscrutables are needed as posits to ground experience but need not be posited to ground structure. This is because, if the possibilities in question are granted, structure could 12 be explained, if it needs to be explained at all, by positing inscrutables other than the ones claimed to be instantiated in the actual world. Schmairs, which would seem to have a rather dubious place in physicalist metaphysics, are likewise similar to purely protophenomenal properties in this respect. Consider a world in which otherwise nonconscious beings become conscious whenever sitting on something with the dispositional and relational characteristics associated with chairs. Other things being equal, it would be appropriate to posit the existence of schmairs, rather than chairs, to explain this very curious fact. Schmairs, like purely protophenomenal properties, would be introduced to explain facts about experience. If the possibilities in question are accepted, the Russellian's inscrutables likewise appear to be similar to purely protophenomenal properties in this respect.15 Second, while the inscrutables of interest are claimed to ground both experience and structure, if the possibilities in question are countenanced, these roles appear very much like distinct and unrelated aspects within them. If these possibilities are accepted, the result is a somewhat radical separation of physical structure from experience; after all, these possibilities involve sameness of structure with radical variation in the distribution of experience. Give this, however, it is very difficult to see how the experience-grounding role and the structure-grounding role of the inscrutables could be thought to flow from some single underlying nature. In this way, if possibilities in question are granted, while it may be true that the Russellian's inscrutables ground both structure and experience, they nonetheless seem to have a distinctive and irreducible protophenomenal aspect. While one might question the very coherence of this-whether it makes sense to suppose that a single property can play what appear, given the possibilities in question, to be rather disparate and unrelated roles-this is not a line of thought that I will pursue. Rather, my more modest point is simply that if purely 15 Note that the claim here and elsewhere is not that the Russellian's inscrutables do not ground the physical structure of the actual world if the possibilities in question are granted. For example, I have not claimed that if these possibilities are granted, it is false that duplicating the inscrutables that are instantiated in our world, and nothing else, suffices to duplicate the relational and dispositional character of our world and, ultimately, the entire world as described by physics. The general proposal is rather that if the possibilities are granted, in this role they are in a sense dispensable. The present claim is that this is one respect in which they are similar to purely protophenomenal properties. 13 protophenomenal properties are not admissible into a physicalist picture, it is not clear why properties with a distinctive and irreducible protophenomenal aspect within them should be any more admissible. This, in part, is probably why schmairs have no place in a serious physicalist worldview-they have an experience-relevant disposition that, given the possibility of chairs, essentially has nothing to do with the more physicalistically-respectable roles they play in the world, such as the role that they play in permitting featherless bipeds to sit upright. Moreover, it is the protophenomenal aspect within the inscrutables of interest that is salient when it comes to saying why these properties should be needed to ground the nature and character of the world; and it is in this role, and not in the structure-grounding role, that they are needed as posits. Third and finally, both purely protophenomenal properties and the inscrutables of interest appear to be unlike the properties in standard forms of physicalism. While standard forms of physicalism assume that some properties are experience-relevant, they do not suppose that this is distinctive or in any way individuative of them. Consider, for example, causal-functionalist ways of understanding nonreductive physicalism. On these views, it is claimed that the realization of a mental property is a matter of some physical property playing a certain causal-functional role in an organism, where the property's playing this role follows from physical laws and the other physical properties instantiated in the organism and the surrounding environment. In this way, that the "physical realizer" is experience-relevant is no way taken to be individuative of it or to make it the property that it is. In contrast, it is experience-relevance that is distinctive of both purely protophenomenal properties as well as the inscrutables in question. In the case of purely protophenomenal properties, the role that they play with respect to grounding experience is distinctive simply because they do not play any other role in grounding the character of the world. In the case of the Russellian's inscrutables, this is because while they ground physical structure, if the possibilities in question are granted, this role appears to be unrelated to the role they play with respect to experience. Likewise, it is experience-relevance that distinguishes them from inscrutables that ground structure but fail to ground experience. Given this, 14 while it may be true that both nonreductive physicalism and Russellianism posit a "dependence base for everything including consciousness", there is some reason to think that the respective dependence bases are not on a par when it comes to having a clear and unambiguous place in physicalist metaphysics.16 Putting this together, if the possibilities in question are taken as genuine, a physicalist probably ought to find the Russellian's inscrutables objectionable, as they prove to be more like purely protophenomenal properties than the properties posited in standard forms of physicalism.17 While I have sometimes followed Montero in putting the issue in terms of whether the inscrutables were "created with us in mind", and used a creation metaphor to help develop my line of thought, my case in no way requires taking this in anything but a metaphorical sense. My argument, for example, is not that if the Russellian countenances the possibility of worlds that are structurally just like the actual world but without experience, there must be some explanation for why the actual world has experience; but the explanation is that the presence of experience in the world was literally "intended" and the very idea that the world was "intended" to have experience is antithetical to physicalism. A Russellian who accepts the possibility of worlds structurally just like the actual world but without experience should offer an explanation of the difference between these worlds and our world. But the answer that the Russellian proposes is that our world has the inscrutables that it does, and I do not think that in saying this, the Russellian is committed to saying that the world was literally "intended" to have experience. My claim is rather about the nature of these inscrutables, and the sense in which they may be experience-specific even if they also ground physical reality. Related to this, my 16 In arguing that the Russellian's inscrutables probably do not have a place in a physicalist picture, I have appealed to "cross world" comparisons-how the possibilities of bare structure and "swapped inscrutables" works into how one should think about the nature of the Russellian's inscrutables. It might be claimed that some of my arguments here do not require appealing to these possibilities. For example, it might be claimed that the charge that the inscrutables seem to have within them an distinctive and irreducible protophenomenal component could be made without appealing to the possibility of "swapped inscrutables". I am not sure that this is correct, as it seems that it is the possibility of "swapped inscrutables" that mandates treating the experiencerelevance of the Russellian's inscrutables to be something like an irreducible protophenomenal aspect within them. In any case, however, it is no objection to my reasoning if the same conclusion about the place of the Russellian's inscrutables in physicalist metaphysics could be drawn using different premises and assumptions. 17 The discussion in the remainder of this section was motivated by comments from two anonymous referees at this journal. 15 claim is not that Russellianism, by countenancing the possibilities in question, entails some kind of religious, antiphysicalist worldview. Again, my claim rather concerns the nature of the inscrutables and the role that they play in determining the character of the world and how accepting certain possibilities works into this issue. One might think that my challenge to the physicalist credentials of the Russellian's inscrutables has the implausible consequence that multiple realization as such is inconsistent with physicalism. In particular, it might be pointed out that the possibilities in question are basically multiple realizabilitytype scenarios-scenarios in which physical structure is either realized differently than in the actual world ("swapped inscrutables") or is somehow "self-realized" ("bare structure"). But it might then be noted that multiple realization is consistent with physicalism, and that there are various ways of developing physicalistic views that accept multiple realization. It might seem, however, that my line of thought supposes otherwise, given that it draws an antiphysicalist conclusion from a kind of multiple realizability, namely the sort that results from supposing that the worlds in question are genuinely possible. While I am not sure that this would amount to a reductio, it is nonetheless worth considering why my case does not entail that, in general, physicalism is inconsistent with multiple realization. Considering this will also help to further articulate the difference between Russellianism and standard varieties of physicalism. For one thing, I have not claimed that the multiple realizability of physical structure as such threatens the status of the inscrutables as physicalistically acceptable. Rather, it is only when combined with a further thesis-that the inscrutables also ground experience-that worries about the physicalistic acceptability of the inscrutables arise. To see this, suppose that in our world, the ground for experience differed from the ground for structure-that in the actual world, there are two kinds of inscrutables, those that underlie experience and those that underlie structure. Such a view would have dubious physicalist credentials, but this would simply be in virtue of positing purely protophenomenal properties. In contrast, in this scenario the status of those inscrutables that ground 16 structure as physicalistically acceptable would in no way be threatened by the claim that this structure is multiply realizable. After all, on the scenario in question these inscrutables not experience-relevant at all. My claim is that when one set of properties is taken to ground structure and experience, and when the possibilities in question are accepted, there is a sense in which these properties are not just experience-relevant but also experience-specific. My further claim is that properties with such a distinctive protophenomenal character may not have much more of a place in physicalist metaphysics than properties that are purely protophenomenal. As indicated by some of the remarks above, in discussions of multiple realizability and physicalism, the standard physicalist assumption is that what is distinctive of a physical realizer property is precisely not that it grounds instances of a mental property. This is arguably part of the very idea that mental properties are realizable by distinct physical properties-a mental property, the idea goes, may have physical realizers that, while distinct, nonetheless play an identical or similar causal-functional role. The assumption is that playing the role definitive of the mental property is not what makes the realizers the properties that they are and is not individuative of them-after all, they are distinct, despite realizing the same mental property. With Russellianism, in contrast, it appears that if the possibilities in question are granted, what is distinctive about the inscrutables is the role that they play in grounding experience. Further, this experience-grounding role does not appear to follow from, or even be closely related to, the role that they play in grounding physical structure. As argued above, the inscrutables are thus unlike the fundamental properties in well-known forms of physicalism. The present claim is that standard ways of understanding multiple realizability, and the fact that the possibilities in question involve a kind of multiple realizability, does not require this verdict to be revised. 3. Conclusion 17 The line of thought I have advanced is not intended to show that a view that posits inscrutables cannot possibly be regarded as a form of physicalism. For one thing, I have only considered one strategy for moving from Russellian monism to physicalism.18 Moreover, I have not claimed that the worlds in question are genuinely possible. I have more modestly attempted to draw out the consequences of accepting such possibilities for thinking about the nature of the Russellian's inscrutables. Likewise, I have not claimed that if the possibilities in question are accepted, and thus that Russellianism cannot easily be understood as a physicalism, it follows that Russellianism should be rejected. This would require supposing, implausibly, that the nonphysicalist character of a view is itself a reason for rejection. Finally, while I have argued that accepting a kind of looseness between the inscrutables and physical structure fits uneasily with the idea that such properties are physicalistically acceptable, there may be various of ways of tightening up this relationship so as to secure the result that the Russellian's inscrutables are not experience-specific in a way that a physicalist ought to find objectionable. For example, if it were held that the relational and dispositional character of the basic constituents of the world requires the inscrutables that are actually instantiated, it could not be said that the distinctive contribution of the inscrutables consists in grounding experience in the way that they do. Rather, they would likewise play an indispensable role in supporting structure.19 While my aims in this paper are modest, the line of thought that I have pursued suggests that how the Russellian spells out the relationship between the "intrinsic", "categorical", or "qualitative" properties of the basic constituents of the world on the one hand and the "extrinsic", "relational", 18 See fn. 9. 19 It will be recalled that the possibilities in question were advanced in response to arguments against physicalism. If these possibilities are rejected, the Russellian might not be able to accept the genuine possibility of worlds physically just like the actual world but without experience, since a world that is physically just like the actual world will have the same experience-grounding inscrutables as our world. While the issue of how to best address and understand the arguments against physicalism requires considerable discussion, a Russellian who ties structure more closely to the inscrutables might claim that despite this close tie, it remains the case that a description of the world in terms of the language of physics fails to capture everything about the world and, especially, that about the world in virtue of which experience is distributed as it is. While a thorough discussion of such proposals is beyond the scope of this paper, I do not believe that they involve an objectionable sort of "brute necessity". Rather, they aim to explain our apparent ability to conceive of physical sameness with experiential difference in terms of the conceptual and representational apparatus of physics. For related discussion, see Alter and Nagasawa 2012, 83-86. 18 "dispositional" properties of these constituents, and indeed the entire world as described by physics, on the other is of some importance. Those sympathetic towards Russellianism have often seemed content with the minimal thesis that the items in the latter category are in some manner determined by or grounded in the items in the former. I doubt that this is a wise strategy. First, the metaphysics of the latter items is itself an area of considerable debate. For example, the metaphysics of dispositions is itself contested, and those serious about defending Russellianism should not assume that "dispositional" even names a distinctive type of property, rather than merely serving as a way of describing some property.20 For my part, I believe that an "identity theory" of the qualitative and the dispositional should be taken seriously, and that if this proves to be the best overall account of dispositions, Russellianism should be explicated with this in mind.21 Similar remarks apply to relations.22 Second, different views about the relationship between the items in these categories have different consequences for Russellianism and its connections with alternative views in the metaphysics of mind. For example, it is difficult to evaluate the extent to which Russellianism is in a better position than explicitly dualistic views when it comes to making sense of mental causation without a detailed account of how the items in these categories are related.23 And as I have argued here, it may be that for Russellianism to qualify as a form of physicalism, the relationship between the Russellian's inscrutables and the physical structure of the world must be closer than recent discussions have supposed. References Alter, T. and Nagasawa, Y. 2012. What is Russellian Monism? Journal of Consciousness Studies 19: 67-95. 20 See Heil 2003. This issue is briefly discussed in Alter and Nagasawa 2012. 21 A Russellianism couched in terms of a qualitative-dispositional identity theory may not look much like standard varieties of Russellianism, precisely because it has been assumed that "dispositional" and "qualitative" name distinct types of properties. Chalmers (forthcoming) briefly considers a variety of Russellianism so understood, but suggests that it will involve an objectionable kind of "brute necessity". While an adequate discussion is beyond the scope of this paper, I will note that while a Russellianism couched in terms of an identity theory may face a variety of issues, I do not think that positing an objectionable sort of "brute necessity" is among them. 22 See Heil 2012. 23 See Chalmers 2015 and Stoljar 2001. For discussion, see Howell 2014. 19 Alter, T. and Nagasawa, Y. (eds). 2015. Consciousness in the Physical World: Perspectives on Russellian Monism. Oxford: Oxford University Press. Chalmers, D. 1996. The Conscious Mind. Oxford: Oxford University Press. Chalmers, D. 2015. Panpsychism and Panprotopsychism. In T. Alter and Y. Nagasawa 2015. Chalmers, D. Forthcoming. The Combination Problem for Panpsychism. In Panpsychism, G. Jaskolla and L. Burntrup (eds). Oxford: Oxford University Press. Heil, J. 2003. From an Ontological Point of View. Oxford: Oxford University Press. Heil, J. 2012. The Universe as We Find It. Oxford: Oxford University Press. Howell, R. 2013. Consciousness and the Limits of Objectivity. Oxford: Oxford University Press. Howell, R. 2014. The Russellian Monist's Problems with Mental Causation. The Philosophical Quarterly 65: 22-39. Ladyman, J. and Ross, D. (with D. Spurrett and J. Collier). 2007. Every Thing Must Go: Metaphysics Naturalized. Oxford: Oxford University Press. Lockwood, M. 1981. What Was Russell's Neutral Monism? Midwest Studies in Philosophy 6: 143-58. Montero, B. 2010. A Russellian Response to the Structural Argument Against Physicalism. Journal of Consciousness Studies 17: 70-83. Montero, B. 2013. Must Physicalism Imply the Supervenience of the Mental on the Physical? Journal of Philosophy 110: 93-110. Montero, B. 2015. Russellian Physicalism. In T. Alter and Y. Nagasawa 2015. Morris, K. 2014. Supervenience Physicalism, Emergentism, and the Polluted Supervenience Base. Erkenntnis 79: 351-365 Ney, A. 2015. A Physicalist Critique of Russellian Monism. In T. Alter and Y. Nagasawa 2015. Pereboom, D. 2011. Consciousness and the Prospects of Physicalism. Oxford: Oxford University Press. Russell, B. 1927/2001. The Analysis of Matter. New York: Routledge. Russell, B. 1956. Mind and Matter. In Portraits From Memory. New York: Simon and Schuster. Stoljar, D. 2001. Two Conceptions of the Physical. Philosophy and Phenomenological Research 62: 253-81. 20 Strawson, G. 2006. Realistic Monism: Why Physicalism entails Panpsychism. Journal of Consciousness Studies 13: 3-31. Unger, P. 1998. The Mystery of the Physical and the Matter of Qualities: a Paper for Professor Shaffer. Midwest Studies in Philosophy 22: 75-99. Wishon, D. 2015. Russell on Russellian Monism. In T. Alter and Y. Nagasawa 2015.