This is the penultimate draft of a paper that will appear in Consciousness in the Physical World: Essays on Russellian Monism, edited by Torin Alter and Yujin Nagasawa, Oxford University Press Pessimism about Russellian Monism Amy Kind akind@cmc.edu According to traditional versions of idealism, everything that exists is mental; according to traditional versions of physicalism, everything that exists is physical. In postulating the existence of only one kind of thing, both idealism and physicalism are versions of monism. However, there has recently been a resurgence of interest in a monism of a different sort, one that does not seem appropriately characterized as either idealism or physicalism, at least not as these views are usually understood. This resurgence began largely with the publication of David Chalmers' The Conscious Mind in 1996.1 In arguing there for the fundamentality of consciousness, Chalmers cast himself as arguing for a version of property dualism but left open the possibility that the fundamentality of consciousness would be best captured by a version of monism: "Perhaps the physical and the phenomenal will turn out to be two different aspects of a single encompassing kind, in something like the way that matter and energy turn out to be two aspects of a single kind." (Chalmers 1996, 129) From the perspective of many philosophers of mind in these early years of the 21st Century, the debate between dualism and physicalism has seemed to have stalled, if not to have come to a complete standstill. There seems no way to settle the basic clash of intuitions that underlies it. But now enters – or perhaps, re-enters – Russellian monism, which promises to show us a new way forward. As Torin Alter and Yujin Nagasawa have recently argued, this view retains the strengths of traditional versions of dualism and materialism while avoiding their weaknesses: Russellian monism is appealing largely because it provides an elegant way of integrating phenomenal consciousness into the natural order without disregarding or distorting the phenomenon's distinctive features. Many philosophers would agree that that result is both desirable and not delivered by traditional theories in the philosophy of mind. (Alter and Nagasawa 2011, 92; see also 88-9)2 1 Maxwell (1978), Nagel (1979), Foster (1982), and Lockwood (1989) offer contemporary explorations of issues relating to Russellian monism that pre-date The Conscious Mind. 2 See also Holman (2008, 49): "The advertising for [Russellian monism] is that it constitutes just the insight needed to break (what many see as) the current impasse on the mind-body problem." Insofar as Russellian monism might allow us to break out of the current gridlock, it's no wonder that it's become "hot stuff."3 To my mind, however, the excitement about Russellian monism is misplaced. That's not to say that I'm pessimistic about the truth of the view. For all that I will say here, some version of Russellian monism might well be true. Rather, what I'm pessimistic about is the claim that Russellian monism enables us to break free of the dualism/physicalism divide. As I will argue, once we properly understand what's required to flesh out an adequate monistic story, we will see that we are in an important way right back where we started. In the first section of the paper, I look closely at Russellian monism in an effort to outline its basic commitments. The second section differentiates and discusses four versions of Russellian monism that have been put forward in the recent literature. Having laid this groundwork, I turn my attention in the rest of the paper to my pessimistic argument. Section 3 argues that the four positions differentiated in section 2 are really best understood as only two different positions. This is a claim I call the collapse thesis. Section 4 addresses an important objection to the collapse thesis, namely, that it relies upon a faulty notion of the physical. Finally, in Section 5, I use the collapse thesis to show that Russellian monism does not really transcend the traditional dualist/physicalist divide as it is usually thought. The same basic issues that arise in the debate between dualism/physicalism re-arise when we attempt to adjudicate between the two versions of Russellian monism. Section 1: What is Russellian Monism? Chalmers' own development of monism owes explicitly to Bertrand Russell, and other contemporary proponents of this sort of monism also cite Russell as a guiding inspiration for their view. In doing so, however, they typically refrain from attributing the view they espouse to Russell. In fact, as we will see in this section, there are some important respects in which many of the contemporary proponents of this sort of monism seem to depart from Russell's own version of the view – though this is hard to determine exactly, since the question of how best to understand Russell's own view is a vexed one.4 In what follows, and in line with current terminological usage, I refer to the emerging constellation of contemporary monist views as versions of "Russellian monism," but it should be understood that, as I use this label, Russell's own view is but one of these versions of Russellian monism. As I will understand things, there are two core claims that a view must be committed to in order for it to count as a version of Russellian monism. First, any such view must be committed to the claim that there exists only a single kind of property at the most fundamental level of reality. That's what makes the view monistic. Second, any such view must also be committed to the claim that these fundamental properties serve as the intrinsic or categorical grounds for physical properties, all of which 3 This phrase was recently used by Sam Coleman (2013) to describe panpsychism, the phenomenal version of Russellian monism. See the discussion of phenomenal monism in Section 2, below. 4 For discussion of how we should understand Russell's own version of Russellian monism, see Stubenberg (2010) and Lockwood (1981). are themselves purely structural or relational. That's what makes the view Russellian. As Russell noted in a key passage from The Analysis of Matter: Physics, in itself, is exceedingly abstract, and reveals only certain mathematical characteristics of the material with which it deals. It does not tell us anything as to the intrinsic character of this material. (Russell 1927/1954, p. 10) Of course, even outside the context of discussions of Russellian monism there is considerable debate about what exactly it means for a property to be categorical in nature and, correspondingly, how the distinction between categorical and dispositional properties should be drawn. Likewise, there is considerable debate about what exactly it means for property to be intrinsic in nature and, correspondingly, how the distinction between intrinsic and extrinsic properties should be drawn. A plausible articulation of at least one of these distinctions – and a defense of its coherence – will be critical for the development of Russellian monism. But that said, I will here sidestep these debates and simply assume that at least one of these distinctions can be intelligibly articulated. Moreover, however intrinsicality and categoricity are to be understood, the Russellian monist is guided by the fact that these fundamental properties, which are not themselves structural or relational, thereby seem in principle to escape the net of physical theorizing: From the perspective of physics, they are incapable of analysis or even scrutiny. Following Montero (2011), I will simply refer to the fundamental properties posited by Russellian monists as inscrutable properties, or more simply, as inscrutables.5 By combining these two core commitments of Russellian monism, we can now define the view as follows: Russellian monism: At the fundamental level of reality there exist inscrutable properties of a single kind. Thus, on my way of categorizing things, someone who is committed to the existence of inscrutable properties but who denies that they are of a single kind would not count as a Russellian monist. Consider a view that is committed to the existence of inscrutables but divides them into many distinct kinds. By my way of categorizing things, such a view is best counted as a version of Russellian pluralism. A view that differentiated them into two distinct kinds would count as a version of Russellian dualism. Depending on how the inscrutables are characterized, such a view is not too dissimilar from traditional versions of property dualism. Though all Russellian monists share a commitment to the existence of a unified class of inscrutable properties at the fundamental level of reality, they disagree about the nature of such properties. The current literature suggests that Russellian monism comes in four different versions: 5 Though he did not use the noun "inscrutables," John Foster had previously invoked the notion of inscrutability in this context: "Scientific analysis uncovers the internal structure of material objects, but terminates in fundamental particles whose intrinsic nature, apart from shape and size, it identifies only opaquely – as that which sustains certain causal powers and sensitivities. In short, the most that empirical investigation (whether ordinary or scientific) can reveal are the number of different fundamental forms of matter, their spatiotemporal distribution and their nomological organization. Beyond this, matter is empirically inscrutable." (1982, 66) a) phenomenal Russellian monism: The inscrutables are phenomenal properties. b) protophenomenal Russellian monism: The inscrutables are protophenomenal properties. c) neutral Russellian monism: The inscrutables are neutral properties, neither phenomenal nor physical. d) physical Russellian monism: The inscrutables are physical properties of a special sort. My discussion here is indebted to Alter and Nagasawa (2012), who helpfully distinguish these same four versions of Russellian monism. However, their understanding of Russellian monism is slightly different from mine. In attempting to specify a general formulation of the view that captures the main components "common to all versions," Alter and Nagasawa build in a claim they call (proto)phenomenal foundationalism: "at least some inscrutables are either phenomenal or protophenomenal properties." (71) In my view, it is a mistake to build this claim into a characterization of Russelliam monism. Either the claim is empty, because anything non-phenomenal ends up counting as proto-phenomenal, or the claim preemptively rules out the possibility of neutral monism and physical versions of Russellian monism.6 Thus, my own categorization of Russellian monism departs from Alter and Nagasawa's in omitting a commitment to (proto)phenomenal foundationalism as a component of the view. My characterization also departs in an important respect from the one offered by Derk Pereboom, who defines Russellian monism as any view that combines (1) categorical ignorance, the claim that physics, or at least current physics, leaves us ignorant of certain categorical bases of physical dispositional properties, with (2) consciousnessor experience-relevance, the proposal that these categorical properties have a significant role in explaining consciousness of experience. (Pereboom 2011, 89) Notice that Pereboom's characterization seems to omit the monistic character of such views, which I take to be central to their aim of offering a position that is importantly different from – and importantly better than – both dualism and physicalism. Pereboom's construal is consistent with there being several kinds of properties that are the categorical basis of dispositional properties. For this reason, I believe that my characterization is to be preferred.7 Section 2: Four Versions of Russellian Monism 6 At the very least, if we build a commitment to (proto)phenomenal foundationalism into Russelian monism, the neutral version and the physical version become significantly constrained: Neutral Russellian monists would have to identify the neutral inscrutables (which by definition are not phenomenal) with protophenomenal inscrutables, and physical Russellian monists would have to identify the physical inscrutables with either phenomenal or protophenomenal inscrutables. The four versions of Russellian monism thus immediately collapse into two. Later, in Section 3, I will argue that a collapse of this sort is inevitable, but I do not want it to turn on a matter of definition. 7 In addition to the point made in the text, it's worth noting that Pereboom's characterization of Russellian monism has an epistemic orientation that I'd prefer to avoid. Alter and Nagasawa (2011, 71) make a similar point. In Section 1, I distinguished four versions of Russellian monism that appear to be in play in the literature. To allow us to better understand what is supposed to differentiate them from one another, this section briefly explores each of the four views. In doing so, I will drop the qualifier "Russellian" and simply refer to these views as phenomenal monism, protophenomenal monism, and so on. Versions of phenomenal monism have been developed by Foster (1982), Rosenberg (2004), and Chalmers (2013a, 2002, 1996), among others. By claiming that the fundamental properties underlying all of physical reality are phenomenal properties, proponents of phenomenal monism seem to be endorsing a version of panpsychism – roughly speaking, the view that everything that exists has a mind.8 Such a view seems, if not outright crazy, at least highly counterintuitive. We're strongly disinclined to attribute mentality even to simplistic organisms like bacteria and protozoa, let alone to non-organisms like quarks and atoms. Of course, in claiming that even quarks and atoms have mentality, phenomenal monists need not claim that these things have mentality in exactly the same way that we humans have mentality. Independent of any commitment to panpsychism, we typically accept the existence of a spectrum of simplicity when it comes to conscious experience. Compare my experience while on a crowded train, where I'm bombarded with sights and sounds and smells, with my experience in an empty, quiet room staring at a white wall before me. The latter experience is considerably simpler than the former, and the phenomenal monist suggests that the experiences of a quark or an atom will be yet simpler still.9 Importantly, such simple experiences need not be imaginable from our point of view. The fact that we cannot imagine what it is like to be a bat does not itself incline us to deny that there is something that it is like to be a bat, and likewise the fact that we cannot imagine what it is like to be an atom should not itself incline us to deny that there is something that it is like to be an atom.10 Ultimately, however, there's no getting around the fact that the phenomenal monist is committed to the idea that there is something it is like – perhaps not much, but something nonetheless – to be a quark or an atom. And even in light of the points made in the previous paragraph, this idea will still strike many as deeply counterintuitive. Much of the recent work on panpsychism has been devoted to alleviating this sense of counterintuitiveness. Relatedly, much recent work in this area has been devoted to the developing potential solutions to the infamous combination problem. Once we assume that there are little bits of consciousness everywhere, we need some explanation as to how they combine to produce the sort of unified consciousness that we experience.11 As it is not my aim in this paper to evaluate the plausibility of the different versions of Russellian monism, I will not here survey this literature. 8 For a helpful discussion about how best to define the panpsychist view, see Skrbina 2005, 15-19. 9 See, e.g., Chalmers' claim that "In the way that an experience of redness is much simpler than a stream of conscious though, we can expect a quark's experience to be much simpler than an experience of redness." (2013, 7) or Rosenberg's claim that the interactions between atoms might simply produce "flashes of extraordinary simple and brief feeling, like fireflies quietly flickering in the night." (2004, 96) I assess the plausibility of Rosenberg's view in Kind 2006. 10 See Rosenberg 2004, 95. 11 See, e.g., Coleman 2012, Chalmers 2013b. In light of the perceived problems facing phenomenal monism, a Russellian monist might be tempted to endorse protophenomenal monism instead. Protophenomenal monism – at least so-called – owes almost entirely to the work of Chalmers (2013a, 2002, 1996), though he does not commit himself to the view.12 According to Chalmers, protophenomenal properties are not themselves phenomenal properties, though in certain cases – when, for example, a sufficiently high degree of structural complexity has been achieved – they give rise to phenomenality.13 Assuming, as seems plausible, that atoms and quarks don't have the requisite degree of structural complexity, the protophenomenal monist need not attribute consciousness to them. Thus, the protophenomenal monist can avoid a commitment to panpsychism. Unfortunately, however, the protophenomenal monist faces a different problem, namely, that of providing a substantive specification of what a protophenomenal property is. Obviously, it is not enough for us simply to be told that they are not phenomenal properties.14 According to Chalmers' characterization of these protophenomenal properties, they are "special properties with an especially close connection to phenomenal properties." (2013a, 13-14) As he understands the notion of specialness, it has two components: (i) protophenomenal properties are distinct from structural properties; and (ii) there will be an a priori entailment between protophenomenal properties and the phenomenal properties to which they give rise. Note that (i) applies to any inscrutable property, at least given how I am understanding the notion of inscrutability. So only (ii) can serve as a potential means for distinguishing protophenomenal properties from other candidates for the inscrutable properties. On first thought, however, there seems to be no reason that (ii) can't be true of either neutral or physical inscrutables, and we are thus left to wonder what in principle could distinguish protophenomenal monism from other versions of Russellian monism like neutral monism or physical monism. I will postpone further discussion of this question until Section 3; first, we need to look more closely at both neutral monism and physical monism. As I mentioned, above it is no easy matter to identify Russell's own version of Russellian monism. But that said, he is generally thought to have espoused some version of neutral monism. We can here look especially to the following passage from The Analysis of Mind: 12 In his 2013a, Chalmers develops what he takes to be the best case for views he calls panpsychism and panprotopsychism. These are the views I am here calling phenomenal monism and protophenomenal monism. Chalmers does not ultimately commit himself to the truth of either of these views. Rather, he notes that he divides his credence fairly equally between these versions of Russellian monism on the one hand and substance dualism (in either its epiphenomenalist or interactionist forms) on the other. Moreover, he does not explicitly indicate whether he thinks one of these versions of Russellian monism is more plausible than the other – though at one point he tentatively suggests that panprotopsychism might have an advantage in "having fewer constraints on its building blocks." (2013a, 22) 13 Nagel's talk of proto-mental properties (Nagel 1979) and Rosenberg's talk of protoexperiential properties (Rosenberg 2004) should not be assimilated to Chalmers' talk of protophenomenal properties. For Nagel and Rosenberg, these "proto" properties are to some degree phenomenal or experiential. As I note in the text above, protophenomenal properties are by definition not phenomenal. 14 Strawson (2006, 22) vividly discusses the difficulty with saying something substantive about the notion of protophenomenality. The stuff of which the world of our experience is composed is, in my belief, neither mind nor matter, but something more primitive than either. Both mind and matter seem to be composite, and the stuff of which they are compounded lies in a sense between the two, in a sense above them both, like a common ancestor. (Russell 1921, 10-11) In elaborating this position, the neutral monist faces a problem parallel to the one facing the protophenomenal monist. Just as the protophenomenal monist owes us a substantive characterization of protophenomenality, the neutral monist owes us a substantive characterization of neutrality. The quoted passage from Russell suggests that we should understand the relevant sense of neutrality as simply "neither mental nor physical," or perhaps, as "neither intrinsically mental nor physical." Note that if we were to understand the dichotomy between the mental and the physical as exhaustive, there would be no room for neutral entities, so the neutral monist who uses this characterization of neutrality must be relying on some other understanding of the mental and the physical.15 There are other passages from Russell, however, that point to a way of understanding the notion of neutrality in terms of causal laws. Russell suggests that in our ultimate scientific account of the world, the causal laws will not be stated in terms of matter; rather, they will be stated in such a way as to apply equally to both psychology and physics (Russell 1921, 305-6; see also Stubenberg 2010). Insofar as we normally understand the mental as subject to distinctively psychological laws and the physical as subject to distinctively physical laws, the existence of a single set of laws governing all particulars would suggest that such particulars were not properly understood as either mental or physical but rather as neutral between the two.16 The last version of Russellian monism, physical monism, has recently been advocated by Stoljar (2001), Montero (2011), and Pereboom (2011).17 Physical monism obviously shares much in common with physicalism, but whether physical monism counts as a version of physicalism will depend on how the physicalist characterizes the nature of the physical. In positing the existence of inscrutables, the physical monist accepts the existence of properties that lie outside the domain of physics – certainly current physics, and quite possibly even ideal physics as well. But the physical monist argues that, insofar as the inscrutables are the categorical or intrinsic bases for normal physical properties, they should still be understood as physical properties in some sense. In other words, the physical monist characterizes the inscrutables as physical properties of a special sort. 15 Papineau, for example, suggests that we can understand "physical" as simply meaning "non-mental" and thus is an example of someone who suggests that the divide between the mental and physical is exhaustive. See Papineau 2001. 16 Nagel 1979 makes a similar point, though he puts it terms of "chains of explanation" (see esp. 184-5). 17 Note that the position advocated by Stoljar 2006 is importantly different from the one advocated by Stoljar 2001, and is not a version of Russellian monism as I have categorized it (see esp. 107-108; 113). Stoljar 2001 makes a commitment to inscrutables; Stoljar 2006 does not. Rather, Stoljar 2006 makes a more qualified commitment to the existence of some properties about which we are ignorant. He notes explicitly that we cannot be sure that such properties are the categorical bases of physical properties, i.e., we cannot be sure that such properties are inscrutables. Since Russellian monism is here defined partly in terms of a commitment to inscrutables, the view advocated by Stoljar 2006 does not count as a version of Russellian monism. Stoljar's distinction between the theory-based conception of the physical and the object-based conception of the physical helps us to clarify this point (Stoljar 2001, 256-7). According to the theorybased conception, physical properties are those that physical theory tells us about plus those that supervene on the sort of properties that physical theory tells us about. Stoljar calls these the t-physical properties. According to the object-based conception, physical properties are those required by a complete account of the intrinsic nature of paradigmatic physical objects and their constituents plus those that supervene on the sort of property required by such an account. Stoljar calls these the ophysical properties. Traditional physicalism seems to operate with something like the theory-based conception of the physical. In contrast, physical monism operates with the object-based conception of the physical. By definition, inscrutables are not t-physical properties. But, since inscrutable properties are required by a complete account of the intrinsic nature of physical objects, they clearly count as o-physical properties. Thus, since the physical monist sees the inscrutables as o-physical properties, we might naturally redescribe physical monism as o-physical monism. Can this really be considered a physical version of monism? The question will turn on whether it's plausible to consider o-physical properties as genuinely physical properties – that is, whether the object-based conception of the physical is really a conception of the physical. I return to this question in the following section. For now, however, it's worth briefly noting that some physical monists have offered specific proposals about what the ophysical inscrutables might be. Pereboom, for example, has recently explored two different possibilities: the Aristotelian notion of prime materiality and the Lockean notion of perfect solidity (Pereboom 2011, 85-101). Section 3: The Collapse Thesis The previous section provided a rough overview of the four different versions of Russellian monism on offer in contemporary discussion. But as I will now argue, once we examine these views more closely we discover that there is not really room for four distinct positions here. Rather the four versions of Russellian monism really collapse into two. Call this claim the collapse thesis. My argument for the collapse thesis proceeds in two steps. First, I suggest that protophenomenal monism does not carve out distinct conceptual space from the other three versions of Russellian monism, so the four versions really collapse into three versions. Second, I suggest that, in the context of Russellian monism, neutral properties are no different from physical properties of a special sort. Thus, the three remaining versions of Russellian monism really collapse into two versions. The first step should be fairly straightforward. Above we saw that one of the standard ways of understanding the notion of neutrality is along the lines of "neither mental nor physical." On this way of understanding neutrality, whatever is not mental or physical will count as neutral by default. Thus, this understanding leaves no conceptual space for protophenomenal properties that lie outside the mentalneutral-physical trichotomy. Protophenomenal properties are by definition not phenomenal, so that means they must either be a species of neutral properties or a species of physical properties. Granted, this is not the only way that we might understand neutrality. So what if we were instead to understand it in terms of causal laws? We saw above that if the set of laws normally thought of as psychological and the set of laws normally thought of as physical could both be recast in terms of a single kind of inscrutable property, it would seem to be plausible to treat the inscrutables as neutral. Here again, though, it seems that protophenomenal monism does not carve out a distinct position. Whatever protophenomenal properties are, it seems that both the set of laws normally thought of as psychological and the set of laws normally thought of as physical will be recast in terms of them. So on the causal law understanding of neutrality, protophenomenal inscrutables are properly understood to be neutral inscrutables. Protophenomenal monism thus collapses into either neutral monism or physical monism, and our quartet of Russellian monist views narrows to a trio. There is no room for protophenomenal monism separate from phenomenal monism, neutral monism, and physical monism. As I am about to go on to argue that this trio of views narrows to a duo, it will not be worth worrying further here about whether it's neutral monism or physical monism into which protophenomenal monism collapses. But there is one point worth noting. In saying that protophenomenal monism collapses into one of these views, I do not mean that protophenomenal monism should be identified with one of these views. Rather, I mean that protophenomenal monism is best understood as a species of one of these views. According to Chalmers' characterization of protophenomenal properties, there will be an a priori entailment between protophenomenal properties and the phenomenal properties to which they give rise. Since it is open to both the neutral monist and the physical monist to deny this a priori entailment, we might think of protophenomenal monism as the a priori version of either neutral monism or physical monism. It likely does not seem that surprising that our four initial versions of Russellian monism reduce to three, for it's likely not that surprising that protophenomenal monism is best understood as a version of either neutral or physical monism. I suspect it seems considerably more surprising, however, that the three remaining versions of Russellian monism – phenomenal monism, neutral monism, and physical monism – might themselves reduce to two versions. But this is what I will now argue. In particular, I want to suggest that there is no neutral monist position that is importantly distinct from phenomenal monism and physical monism as we have understood them. One way to make my argument for the collapse thesis would be to push a point a claim that was mentioned in passing in Section 2 above. Suppose that the dichotomy between the mental and the physical is exhaustive. In this case, the existence of neutral entities – entities that are neither mental or physical – is ruled out by default. So, an argument for the claim that the mental/physical dichotomy is exhaustive would in turn show that there are no such thing as neutral inscrutables and hence that there can be no neutral version of Russellian monism. Since on this line of argumentation the alleged neutral entities are made to disappear entirely, I will call it the disappearance strategy. Though my argumentative strategy has some natural affinity to the disappearance strategy, it is in other ways importantly different. In particular, I am not committed to the claim that there is no room for entities that are neutral between the mental and the physical.18 Rather, I am committed only to the claim that there is no room for genuinely neutral inscrutables. Inscrutables, recall, are the categorical or intrinsic bases for physical properties. Physical theory defines mass solely in terms of its structural role. But what is it that plays this role? Whatever it is, our physical theory does not have the means to tell us anything about it. This inscrutable underlies a physical property par excellence – and likewise for the other inscrutables. Moreover, as we saw in Section 2, physical monism operates with an object-based conception of the physical. On this conception, a property is physical if it is required by (or supervenes on what is required by) a complete account of the intrinsic nature of paradigmatic physical objects and their constituents. Inscrutables clearly fit the bill. So if we accept that the object-based conception of the physical is an appropriate conception of the physical, then the kinds of inscrutables posited by the neutral monist posits are better described as physical – that is, as o-physical – than as neutral.19 This brings us back to a question about which I earlier postponed discussion: Should we accept the object-based conception of the physical? In answering this question, I am in something of a delicate position. Though I want to deny that there's room for a neutral version of Russellian monism, I do not want to deny that there's room for a phenomenal version of Russellian monism. And it looks like the object-based conception of the physical would classify even phenomenal inscrutables as physical. So if I accept that the object-based conception of the physical is really a conception of the physical, then it looks like my argument will prove too much. To show that neutral monism collapses into physical monism without also showing that phenomenal monism collapses into physical monism, I need a principled way of classifying the physical that includes neutral inscrutables without also including phenomenal inscrutables. Fortunately, there is such a classification available. Many physicalists endorse a "no fundamental mentality" (NFM) constraint on the notion of the physical – that is, they deny that an entity that is fundamentally mental can count as a physical entity.20 To accept such a constraint is to deny that we can fully understand the notion of the physical in terms of physics. If an ideal future physics were to incorporate entities with fundamental mentality into its theorizing, then NFM physicalists would claim that physicalism turns out to be false. NFM physicalism can accept that future physics might posit entities that are radically different from those posited by current physics, but if any such entities turn out to have fundamental mentality, then they would no longer count as physical. 18 Numbers, for example, might be plausibly understood as abstract objects that are neither physical or mental. It is in part due to examples like this that I avoid the disappearance strategy and its commitment to the claim that the mental/physical dichotomy is exhaustive. 19 As Daniel Stoljar has pointed out to me, once we have the t/o distinction in play, we can then define different notions of neutrality. In particular, a t-neutral property is one which is neither t-physical nor mental. An o-physical property that is not a t-physical property will thus be t-neutral. But since physical monism is operating with an obased conception of the physical, it seems that the notion of neutrality in play in the relevant discussion should be o-neutrality. 20 The need for such a constraint is forcefully argued by Wilson 2006. In explaining the notion of fundamental mentality she notes that an entity that lacks fundamental mentality "does not individually either possess or bestow mentality." (Wilson 2006, 72) See also Ney 2008 for discussion. Those physicalists who endorse the NFM constraint are typically working with a theory-based conception of the physical. But there is no reason that we can't incorporate an NFM constraint into an object-based conception of the physical. A property would be o*-physical if (1) it is not fundamentally mental; and (2) it is required by (or supervenes on what is required by) a complete account of the intrinsic nature of paradigmatic physical objects and their constituents. By adopting the corresponding o*-based conception of the physical, we can count the neutral inscrutables as physical without also counting the phenomenal inscrutables as physical. Section 4: An Objection In the previous section, I presented my argument for the collapse thesis. If this argument is correct, then there are not really four distinct versions of Russellian monism but only two. In developing this argument, I committed myself to the claim that the o*-based conception of the physical can be properly considered to be a conception of the physical. Thus, to block my argument for the collapse thesis, someone might object to this claim. There are two ways such an objection might go. First, someone might accept that the o-based conception of the physical is really a conception of the physical, but reject the addition of the NFM constraint. Second, one might reject the o-based conception of the physical. I'll take these in reverse order. The most obvious way of rejecting the o-based conception of the physical would be to retreat to a t-based conception of the physical.21 But it's important to note that this retreat entails rejecting altogether the possibility of a physical version of Russellian monism. Given that the inscrutables are by definition inaccessible to physical theory, they are by definition excluded from the class of t-physical properties and cannot be accommodated within the t-based conception of the physical. So an insistence that the only adequate conception of the physical is a t-physical one amounts to a denial of the coherence of physical monism. Importantly, however, the denial of the object-based conception of the physical is consistent with the collapse thesis, i.e., with the claim that Russellian monism narrows from four options to only two options. The o-physical inscrutables are either phenomenal or not. I take it that the physical monists typically take them to be non-phenomenal.22 Moreover, if they were phenomenal, physical monism would turn out to be a version of phenomenal monism. But if the o-physical inscrutables are not phenomenal, and they've been excluded from the class of physical properties, then that would suggest that they are best understood as neutral. In this case, the collapse thesis would still hold, though the two remaining versions would be phenomenal monism and neutral monism rather than phenomenal monism and physical monism. 21 There might be other ways of rejecting the o-based conception of the physical without retreating to the t-based conception of the physical. Chalmers, for example, distinguishes between the broadly physical and the narrowly physical and argues that this distinction is not the same as Stoljar's distinction between the o-physical and the tphysical (see, e.g., his 2013a, 9-10). But the basic argument I give in the text should apply equally well, mutatis mutandi, were we to use Chalmers' distinction rather than Stoljar's. 22 This might suggest commitment to the NFM constraint. In my view, at this point the dispute ends up being largely a verbal one. It is hard to see what would turn on whether we classify the non-phenomenal version of monism as neutral monism or as physical monism. But if there is a substantive issue here, there is also an easy way to avoid taking a stand on it: We could simply label the two remaining versions of Russellian monism as phenomenal monism and non-phenomenal monism, and all subsequent discussion could then be recast in terms of this way of drawing the contrast. (In what follows, I will continue to use the label physical monism, but a reader who is uncomfortable counting the o-physical as physical should feel free to substitute nonphenomenal.) As we've seen, then, a rejection of the o-physical conception of the physical does not count against the collapse thesis. We need now to return to the first objection – that is, we need to address the concerns of someone who accepts the o-physical conception of the physical but who denies the acceptability of the NFM constraint. To my mind, there's considerable plausibility to the idea that physicalism is committed to a lack of fundamental mentality, but not everyone agrees, and to engage fully with this debate here would take us too far afield.23 Recall the role played by the NFM constraint: It enables us to argue that neutral monism collapses into physical monism without having to claim that phenomenal monism collapses into physical monism. In the absence of this constraint, even phenomenal inscrutables could be classified as physical inscrutables. Our initial quartet of versions of Russellian monist would then be reduced to but a single version. Importantly, however, even if we are left with only physical monism, the distinction in which I am primarily interested – and which underlies the overall pessimistic argument of this paper – would not disappear. That distinction is between the phenomenal and the non-phenomenal. If someone wants to treat phenomenal monism as a version of physical monism, so be it – but notice that there will still be two importantly different kinds of positions here: one we might call phenomenal physical monism and the other what we might call non-phenomenal physical monism. Ultimately, it does not matter for my purposes whether we say that there are two versions of Russellian monism, or whether we say that there are two sub-types of physical monism. In both cases, we are forced to confront the basic dichotomy between the phenomenal and the non-phenomenal. As I will argue in the following section, the re-appearance of this basic dichotomy means that, contrary to its advance billing, Russellian monism is unable to meaningfully transcend the dualism/physicalism divide. Section 5: The Case for Pessimism I begin this final section with two tales. First, the tale of the disenchanted dualist. Once upon a recent time there was a philosopher with deeply entrenched dualist inclinations, but who had grown disenchanted with the traditional forms of dualism on offer. She was deeply convinced that no reductive theory of consciousness will succeed, that consciousness is a fundamental part of reality. But she was also deeply frustrated by the inability of 23 See Dowell 2006 and Ney 2008 for useful discussions. existing versions of dualism to account adequately for the reality of mental causes. Then one day she was visited by the ghost of Russell past, who showed her that Russellian monism could provide her with almost exactly what she's looking for. Sure there was a cost: She had to give up on her intuition that the mental and the physical are as radically different as she had thought, since Russellian monism claims that both the mental and the physical would arise from the inscrutables of a single sort. But there was also a benefit: She now had a potential answer to the problem of mental causation, since it would be plausible for mental causes to inherit causal efficacy from the inscrutables that underlie them. The details would have to be worked out, of course. But she had good reason for hope, and she lived happily ever after. Next, the tale of the disenchanted physicalist. Once upon a recent time there was a philosopher with deeply entrenched physicalist inclinations, but who had grown disenchanted with the traditional forms of physicalism on offer. She was deeply convinced that some reductive theory of consciousness will succeed, that consciousness is not a fundamental part of reality. But she was also deeply frustrated by the inability of existing versions of physicalism adequately to address the array of conceivability arguments (e.g., zombie arguments) leveled against them. Then one day she was visited by the ghost of Russell past, who showed her that Russellian monism could provide her with almost exactly what she's looking for. Sure there was a cost: She had to give up on her intuition that physicalism can be explained in terms of physics, since inscrutables are by definition out of the reach of physics. But there was also a benefit: She now had a potential answer to the conceivability arguments, since it would be plausible to deny that we can conceive of a zombies who is identical to a conscious being even with respect to inscrutables but yet who lacked consciousness. The details would have to be worked out, of course. But she had good reason for hope, and she lived happily ever after. Hearing these two tales, it might appear that the disenchanted dualist and the disenchanted physicalist have both happened upon the same bag of magic beans, as it were. The tales suggest that they have converged on a single position – that they have transcended the dualist/physicalist divide. But this is simply an illusion. There are no magic beans. Or, perhaps better: The disenchanted dualist is planting a completely different sort of magic beans from those being planted by the disenchanted physicalist. While it is true that they have both adopted versions of Russellian monism, the distance between them seems to me as great as ever. In particular, they still disagree on the basic question of whether consciousness is part of the fundamental nature of reality. The disenchanted dualist will insist that the inscrutables are phenomenal, while the disenchanted physicalist will insist that the inscrutables are non-phenomenal. And the clash of intuitions between them will be just as great as it has always been. To my mind, this simple point has been obfuscated by the proliferation of different views in the recent philosophical literature that have been classified as versions of Russellian monism. I don't mean to suggest that this classification is incorrect. Insofar as each of the views is committed to a single class of inscrutables, they seem appropriately considered as views of this type. But by focusing on the respects in which these views depart from traditional versions of dualism and traditional versions of physicalism, and by focusing on what they have in common, we appear to have a made a certain kind of progress that, in my view, we have not made. Consider, for example, the following claims made about Russellian monism (or particular versions of Russellian monism): [Phenomenal monism] offers resolutions to mind-body problems that dualism and materialism find intractable. Present philosophy of mind is dominated by materialist theories that cannot adequately address issues of consciousness, qualia, or the role of mind in the universe. Dualism is the traditional alternative, but it too suffers from long-standing weaknesses and unanswered questions. [Phenomenal monism] offers a third way. (Skrbina 2005, 4) But even where there is substantial overlap with traditional theories, Russellian monism provides a distinctive perspective on consciousness, the world as revealed by physical science, and the relationship between the two. (Alter & Nagasawa 2011,83) The discussion of this paper helps us to see how these claims can be misleading. Once we clear away the clutter, so to speak, we see that there are really only two possibilities for the nature of inscrutables: they must be either phenomenal or physical. That means that a Russellian monist must endorse either phenomenal monism and physical monism. To my mind, these two views are as different from one another as traditional dualism and traditional physicalism are. Any attempt to adjudicate between them will have to settle the question as to whether consciousness is a fundamental part of nature – the same question that needs to be adjudicated in the debate between dualism and physicalism. Granted, we often describe the basic issue that divides dualism and physicalism in a slightly different way. As defined by the Stanford Encyclopedia of Philosophy, dualism "is the theory that the mental and the physical-or mind and body or mind and brain-are, in some sense, radically different kinds of thing." (Robinson 2012) This claim is denied by both physicalists and idealists; physicalists conjoin their denial that the mental and the physical are radically different kinds of things with the further claim that the physical kind of thing is more basic. So the issue between dualism and physicalism might seem to be an issue about how many kinds of things there are – two or one. Notice, however, that the reason that the dualist thinks that there are two kinds of things is that she thinks that consciousness is an irreducible part of nature. And it's this that the physicalist denies. Thus, the common description of what separates dualism from physicalism cannot be invoked to dispel my pessimistic conclusion. Does this mean that phenomenal monism is just a version of dualism, while physical monism is a version of physicalism? In collapsing into these two versions, does Russellian monism simply collapse back into dualism and physicalism? To properly answer these questions, we would first have to undertake a careful look at the commitments of both traditional dualism and traditional physicalism. We would then have to evaluate whether the respect in which phenomenal monism departs from the commitments of traditional dualism outweighs the respect in which it shares such commitments. We would have to do likewise for physical monism/traditional physicalism. But how exactly should these things be weighed? At this point, we might worry that things have devolved into merely a verbal dispute. Chalmers, for example, claims exactly this. In considering the question of whether Russellian monism is "a form of physicalism, dualism, or something else," he notes that it "is a largely verbal question that we need not settle." (2013a, 16) I myself do not feel the temptation to dismiss the debate here as merely verbal. Moreover, I'm myself inclined to give affirmative answers to the questions above, i.e., I'm inclined to see Russellian monism as dividing into a version of dualism and a version of physicalism, both of which would be nontraditional in important respects. Insofar as this non-traditionality might be thought to count against the classification, or to make it seem as if it's only a verbal question, it might be helpful to consider, for example, two views that are both uncontroversially counted as versions of dualism: Cartesian dualism and epiphenomenalism. Cartesian dualism is a view about substances. It is also interactionist in nature. Epiphenomenalism is a view about properties, and it rejects interactionism. It seems clear that it differs in pretty crucial ways from the Cartesian picture. Yet we count epiphenomenal dualism as a version of dualism, and we're not at all inclined to consider the question of whether this classification is correct as merely a verbal one. Fortunately, however, the overall argument of this paper does not require me to take a stance on these issues. My pessimism about Russellian monism will still be warranted even if one is not inclined to accept that Russellian monism collapses into either dualism or physicalism, and it will likewise be warranted even if one is inclined to dismiss the issue itself as one that it not substantive. For whatever one's stance on these issues, it remains the case that the Russellian monist owes us an account of the nature of the inscrutables. As I have argued in this paper, the development of this account will involve a choice between two options: phenomenal monism and physical monism. This choice hinges on the issue of whether the inscrutables are phenomenal. If this choice is not flatly the choice between dualism and physicalism, it is at the very least not too far removed from that choice. And so we are thus essentially back where we started. Of course, that's not to deny that some progress has been made along the way. There might be reasons to think that phenomenal monism improves upon traditional dualism. There might likewise be reasons to think that physical monism improves upon traditional physicalism. But the central divide in philosophy of mind remains unbridged. In conclusion, nothing that I've said in this paper is meant to show that Russellian monism is false. Though my argument here has been a pessimistic one, my pessimism concerns not the truth of the view but rather its ability to transcend the dualist/physicalist divide. I started this section with two tales, but in my view, philosophy of mind can be largely seen as a tale of two philosophies. It's been hoped that Russellian monism would close the chapter on that story, and begin a new one – one that provides us with the best of times without the worst of times. As I've suggested in this paper, however, that hope is misguided.24 References 24 I'm grateful to Peter Ross and Peter Thielke for helpful discussion of issues related to Russellian monism. Thanks also to Torin Alter, Dustin Locke, Frank Menetrez, Yujin Nagasawa, and Daniel Stoljar for helpful comments on a previous draft of this paper. Alter, Torin and Yujin Nagasawa. 2012. "What is Russellian Monism?" Journal of Consciousness Studies 19: 67-95. Chalmers, David. 2013a. "Panpsychism and Panprotopsychism." Draft available at http://consc.net/papers/panpsychism.pdf. Chalmers, David. 2013b. "The Combination Problem for Panpsychism." Draft available at http://consc.net/papers/combination.pdf Chalmers, David. 2002. "Consciousness and its Place in Nature." In Philosophy of Mind: Classic and Contemporary Readings, ed. David Chalmers, 247-272. Oxford: Oxford University Press. Chalmers, David. 1996. The Conscious Mind. Oxford: Oxford University Press. Coleman, Sam. 2013. Review of Michael Blamauer, ed., The Mental as Fundamental: New Perspectives on Panpsychism. Notre Dame Philosophical Reviews. http://ndpr.nd.edu/news/28297-the-mental-asfundamental-new-perspectives-on-panpsychism/ Coleman, Sam. 2012. "Mental Chemistry: Combination for Panpsychists." Dialectica 66: 137–166. Dowell, Janice. 2006. "Formulating the Thesis of Physicalism: An Introduction." Philosophical Studies 131: 1-23. Foster, John. 1982. The Case for Idealism. London: Routledge & Kegan Paul. Homan, Emmett L. 2008. "Panpsychism, Physicalism, Neutral Monism and the Russellian Theory of Mind." Journal of Consciousness Studies 15: 28-67. Kind, Amy. 2006. "Panexperientialism, Cognition, and the Nature of Experience." Psyche 12, http://www.theassc.org/files/assc/2657.pdf Lockwood, Michael. 1989. Mind, Brain, and the Quantum. Lockwood, Michael. 1981. "What Was Russell's Neutral Monism?" Midwest Studies in Philosophy 6: 143-58. Maxwell, Grover. 1978. "Rigid Designators and Mind-Brain Identity." In Minnesota Studies in the Philosophy of Science, Vol. 9, ed. C. Wade Savage, 365-403. Minneapolis: University of Minnesota Press. Montero, Barbara. 2011. "A Russellian Response to the Structural Argument Against Physicalism." Journal of Consciousness Studies 17: 70-83. Nagel, Thomas. 1979. Mortal Questions. Cambridge: Cambridge University Press. Ney, Alyssa. 2008. "Defining Physicalism." Philosophy Compass 3: 1033-1048. Pereboom, Derk. 2011. Consciousness and the Prospects of Physicalism. Oxford: Oxford University Press. Robinson, Howard. 2012. "Dualism." In The Stanford Encyclopedia of Philosophy (Winter 2012 Edition), ed. Edward N. Zalta, http://plato.stanford.edu/archives/win2012/entries/dualism/ Rosenberg, Gregg. 2004. A Place for Consciousness. Oxford: Oxford University Press. Russell, Bertrand. 1927/1954. The Analysis of Matter. New York: Dover Publications. Russell, Bertrand. 1921. The Analysis of Mind. New York: The Macmillan Company. Skrbina, David. 2005. Panpsychism in the West. Cambridge, Mass.: The MIT Press. Stoljar, Daniel. 2006. Ignorance and Imagination. Oxford: Oxford University Press. Stoljar, Daniel. 2001. "Two Conceptions on the Physical." Philosophy and Phenomenological Research 62: 253-2181. Strawson, Galen. 2006. "Realistic Monism: Why Physicalism Entails Panpsychism." Journal of Consciousness Studies 13: 3-31. Stubenberg, Leopold. 2010. "Neutral Monism." In The Stanford Encyclopedia of Philosophy (Spring 2010 Edition), ed. Edward N. Zalta. Available at http://plato.stanford.edu/archives/spr2010/entries/neutral-monism/ Wilson, Jessica. 2006. "On Characterizing the Physical." Philosophical Studies 131: 61-99.