Recent Naturalistic Dualisms
William G. Lycan
In E. Meyers, R. Styers & A. Lange (eds.), Light Against Darkness: Dualism in Ancient Mediterranean Religion and the Contemporary World. Brill Academic Publishers (2007)
This paper is about a certain family of philosophical positions on the mind-body problem. The positions are dualist, but only in a minimal sense of that term employed by philosophers: according to the positions in question, mental entities are immaterial and distinct from all physical things. Thus, the positions are united in opposing the monist doctrine of mind-body materialism, roughly that everything mental or psychological is entirely constituted by physical matter.
An Anglo-American philosopher of mind who hears the label “dualism” first thinks of mind-body dualism and Descartes’ doctrine of persons as being immaterial, nonphysical egos or subjects. That doctrine faces daunting objections, and, though it still has a few adherents, Cartesian dualism now qualifies as a bugbear. In particular, it is thought to be in deep tension with what is known about biology, chemistry and physics.
According to Descartes, minds are entirely immaterial things, only contingently related to human bodies; indeed, they do not even have spatial properties, for spatial “extension” is what Descartes held to be characteristic of matter. That gives rise to a first objection to his view: It is almost undeniable that the mind interacts causally with the body, but it is also almost impossible to understand how a thing that has no location in physical space could interact causally with things that are so located. Descartes was well aware of this problem, but confessed that he had no solution to it. (He suggested that the interaction works through the pineal gland and that the mind has its “main seat” there (p. 346), but he also said that he is “not only lodged in [his] body as a pilot in a vessel”, but “[is] so to speak “intermingled” with his whole body (p. 192)”. [T]he soul is really joined to the whole body, and “we cannot, properly speaking say that it exists in any one of the parts to the exclusion of the others” (p. 345).Yet the mind still has “no relation to extension, nor dimensions, nor other properties of the matter of which the body is composed” (p. 345).This was flailing.)
Further problems for Descartes’ dualism are created by more specific scientific facts. One fact often cited is that of evolution by natural selection. It is hard to see how the addition of an immaterial Cartesian ego could have conferred an adaptive advantage on homo sapiens, increasing the reproductive fitness of individuals that had it. (But perhaps this is just to repeat the interaction problem, for if that problem were solved, there would be no further mystery as to how having a mind would be advantageous.)
A worse difficulty is posed by the conservation laws of physics. Descartes knew about the conservation of what he called “quantity of motion,” i.e., mass times speed, which did not exclude the causing of something physical by something purely mental (he seems to have held that the immaterial mind can affect the direction of motion without affecting its “quantity”). But it is harder if not impossible to reconcile the activity of an alleged Cartesian ego with the more thoroughgoing conservation of physical matter-energy. We can imagine or picture in a superficial way, that we might look into a normally functioning human brain and discover that the electrical energy coming up the afferent pathways hits the pineal gland and disappears into thin air, and that further energy comes from nowhere and activates efferent impulses eventuating in motor responses, but that would contradict everything we think we know about physics and about physiology.
Finally, given the availability of purely physical explanations for all (nonrandom) physical events including human actions, Cartesian egos are explanatory excrescences. Gilbert Ryle had argued that such entities are not implied even by ordinary talk about the mental. In light of 21st-century physics and neuroscience, it seems there is no more reason to believe in Cartesian egos than in ghosts, ectoplasm, or spookstuff of any other sort.
Much less unpopular than Cartesian dualism is “property dualism” about the mind. A property dualist need not accept immaterial Cartesian egos, ghost persons, but maintains only that sentient biologic beings have special emergent immaterial or nonphysical properties along with their ordinary biological and physical properties. These special properties are of two kinds. One kind is that of the subjectively felt phenomenal qualities of sensations: the vivid color of an after-image, the smell of a smell, what it is like to hear soprano C# as played by Jean-Pierre Rampal, or the achy feel of a particular pain. Such properties, it is argued, are not themselves physical even if they are properties of otherwise physical beings; they could not consist simply in arrangements or configurations of physical stuff.
The other kind of special property is the “intentional” kind as Franz Brentano called it, the aboutness of some mental states such as thoughts, beliefs and desires. Most remarkably, my thoughts and beliefs can be about nonexistent things, such as Santa Claus and Sherlock Holmes, and just as easily as they can be about real things and people such as the Eiffel Tower and George W. Bush. Brentano argued that purely physical or material objects cannot have such intentional properties: for how could any purely physical entity or state have the property of being about or “directed upon” a nonexistent thing?
In eschewing Cartesian egos themselves, property dualism is felt to be more credible than Cartesian dualism. But it is not entirely clear why. Although the property dualist cannot be accused of belief in ghosts, ectoplasm etc., his or her special emergent properties raise most of the same problems that Cartesian egos do. The interaction problem in particular: How are the special emergent properties supposed to interact causally with physical properties? And how is that supposed to be accommodated by the conservation laws?
More interesting than either Cartesian dualism or traditional property dualism is a recent flowering of “naturalistic” dualism, which is my main topic.
The idea of “naturalistic” dualism is to respect natural science entirely, denying nothing that is known, rejecting only the classical mechanistic 19th-century view according to which nothing fundamentally exists but individual subatomic particles and their dynamic and kinematic properties. According to the naturalistic dualist, the foregoing objections to Cartesian and property dualism are at least tacitly based on the classical view, and can be circumvented if we abandon that view.
Naturalistic dualism was inaugurated by Wilfrid Sellars in the 1950’s, although the idea did not catch on until thirty or forty years later. Sellars argued (at great length) that the subjectively felt phenomenal qualities of sensations “the first kind of special property mentioned in section 2” could not be identified with, otherwise reduced to, or even accommodated within the “punctiform” metaphysics afforded by classical particulate mechanics. He called such subjective qualitative properties “sensa”. But, rather than insisting that sensa are outside physical reality itself, Sellars contended that they will have a home within a suitably expanded physics, and so are part of nature after all:
The important thing is not to let our reflections on the developing Scientific Image of man-in-the-world be tied too closely to the current institutional and methodological structure of science, or, above all, to its current categorial structure.... Sensa are not “material” as “matter” is construed in the context of a physics with a particulate paradigm. But, then, as has often been pointed out, the more seriously this paradigm is taken, and the more classically it is construed, the less “matter” there seems to be.
As microphysics continues to get weirder, it would be stupid to insist on a 19th- or even on a 20th-century conception of ultimate matter; it is hardly our place to second-guess the physicists. By the time the mental is actually reduced to anything, physics may well be other than physics as conceived in the 2000s. (Sellars thought of his sensa as “pure” or subjectless processes, on the model of it’s raining in a given region. The raining is not the activity of any individual thing or subject, but is merely a process; “It” in “It’s raining” is not a name. Similarly, red after-imaging is going on, or there is painful aching now. And Sellars thought that microphysics would move in the direction of positing pure processes rather than ultimate particles, thereby relieving sensa from their tension with the Newtonian particulate paradigm.)
Thus, Sellars proposed that although there are mental properties that are “immaterial” by traditional standards, and classical materialism and physicalism must be rejected, those mental properties can still be accommodated within a wider but still naturalistic and scientistic worldview, once we reject the classical picture of microphysics.
Before I proceed to discuss the doctrine of naturalistic dualism, I want to mention two predecessor views that can be seen as paving the way for it. There are degrees or extents of departure from classical materialism, physicalism or microphysics itself. The degrees of departure tend to coincide with degrees of willingness to call oneself a dualist despite one’s avowed rejection of classical materialism. The two predecessor or John-the-Baptist views, I would maintain, are dualist in spirit even though not in fact.
The first view I shall call “physicsalism”. Physicsalism tries to account for mental phenomena within the bounds of already known nonclassical physics, paradigmatically quantum mechanics. On this view, contra Sellars himself, neither contemporary physics nor our concept of matter will have to change. For example, Michael Lockwood identifies one’s total subjective awareness at a time (what Sellars would say is the totality of one’s sensa at that time) with a designated quantum eigenstate of one’s brain. Roger Penrose invokes quantum phenomena to explain the possibility of causal interaction between “immaterial” mental properties and physical things, citing the brain as an extraordinarily complex magnifier of quantum micro-effects.I say that these views are dualist in spirit because their proponents will not grant the identification of mental states and events with brain states and events unless further special things about weird quantum phenomena, are said about the brain. They make the mind more special than other very complex but entirely physical information-processing systems.
I have two general objections to the physicsalist appeal to quantum mechanics. The first is that its proponents have made no connection with actual mental phenomena. In particular, nothing about subjective or qualitative properties (the redness of the after-image, the felt quality of the ache, etc.) has been explained or even potentially explained by reference to distinctive quantum effects. Until recently at least, the argument has been essentially that (1) subjective mental phenomena are weird and mysterious, (2) quantum effects are weird and mysterious, and so (3) subjective mental phenomena are quantum effects which is not very good reasoning. Very recently, a few more specific suggestions have been offered by quantum enthusiasts, but they are still rudimentary and vague; and (much more to the point) it has not been argued that the classical materialist lacks corresponding explanatory resources.
My second objection is that no physicsalist author has succeeded in establishing any particular difference between quantum and classical mechanics that does the work of accommodating the mental properties that allegedly cannot be reconciled with classical physics. The physicsalist’s idea is that although there are sound dualist arguments to show that some mental properties are immaterial relative to Newtonian matter, those same arguments do not show that the “immaterial” properties are outside of nature.(If there are no arguments of this kind, (a) no one would need to be a mind-body dualist of any sort, and also (b) there would be no occasion for adverting to quantum mechanics.) But I know of no such arguments. That is partly (and degenerately) because I do not believe there are any sound arguments for the “immaterial” properties in the first place, but never mind. When we consider some of the more impressive dualist arguments that have been offered, it is easy to see that if they succeed against materialism understood in terms of Newtonian matter, they also succeed against naturalism in the physicsalist’s broader sense.
To take a leading example, Frank Jackson’s much-anthologized “Knowledge Argument” for mind-body dualism runs as follows. Consider Mary, a brilliant color scientist who happens herself to be entirely color-blind. She becomes scientifically omniscient as regards the physics and chemistry of color, the neurophysiology of color vision, and every other conceivably relevant scientific fact; we may even suppose that she becomes scientifically omniscient, period. Then she is cured of her color-blindness and actually sees colors for the first time. And she thereby learns something, viz., she learns what it is like to see red and many of the other colors. (That is, she learns what it is like to experience subjective redness, never mind the actual colors of the physical objects she encounters, which she already knew.)But by hypothesis, she already knew all the relevant scientific facts; so the fact she has now learned, that of what it is like to see red, is not a scientific fact and cannot be captured by science.
What is important about Jackson’s argument for present purposes is that it is entirely neutral as regards what the relevant scientific facts are. It does not care whether they are neurophysiological, chemical, Newtonian, or quantum-mechanical. All that matters is that the facts can be formulated in the public language of some science. What Jackson meant to show was that properties of the form “what it’s like to experience -----” are intrinsically perspectival, and cannot be expressed in any public language at all. The move from classical physics to quantum mechanics would in no way blunt the Knowledge Argument. In fact, if sound, the argument shows that the relevant mental properties cannot be quantum properties.
The second predecessor view I shall call “quietism”. The quietist denies the usefulness or even the coherence of the standard “material”/”immaterial” or “physical/nonphysical” distinction, while still cleaving to actual or foreseeable physics. “Physics” may or may not have to change, on this view, but now the concept of matter is up for grabs. The foregoing quotation from Sellars states the view, though Sellars himself was an outright naturalist dualist. More recently, Noam Chomsky has defended it:
Newton exorcised the machine, not the ghost: surprisingly, the principles of contact mechanics are false, and it is necessary to invoke what Newton called an “occult quality” to account for the simplest phenomena of nature, a fact that he and other scientists found disturbing and paradoxical...
These moves also deprive us of any determinate notion of body or matter. The world is what it is, period. The domain of the “physical” is nothing other than what we come more or less to understand, and hope to assimilate to the core natural sciences in some way, perhaps by modifying them radically, as has often been necessary.
There is no denying that physics persistently encounters new phenomena and innovates in a way that shocks the older generation conceptually: action at a distance; electromagnetism; relativity; Riemannian spacetime; quantum indeterminacy; the paradoxes of quantum mechanics; tachyons; antimatter. It does not stop being physics, and its practitioners do not thereby depart from naturalism.
The quietist argues that he or she is a “dualist” only relative to classical mechanics, and that the “material”/”immaterial” distinction is now otiose. But, I object, there is a way of marking the difference between dualism and materialism even allowing for a conceptually expanded physics and without presupposing any tendentious notion of “matter”: Start with a list of all the known mental properties. It would be a long list, including not just Sellars’ sensa but things like a desire for a shower, the belief that broccoli will kill you, and embarrassment at having misquoted someone. Now make that list open-ended, by reference to some general features that many mental states and events characteristically have: sensa or other subjective qualitative properties themselves, and also “intentional” properties (any property that consists in a state’s or event’s being about something, such as a thought about chocolate or a belief about the Easter Bunny). Then characterize “materialism” as bluntly excluding all such mental properties at the level of fundamental entities: Materialism will then be the claim that any subject of mental properties must be composed solely of basic elements that individually do not have them, and for anything that has a mental property, its doing so must consist entirely in an arrangement of the basic components. That reinstates a clear and nonarbitrary distinction between materialism and mind-body dualism, without appeal to any prior understanding of “matter”.
Finally we come to naturalist dualism itself. It is even more ambitious, having it that science will eventually itself be forced to recognize new primitives that are not found or even readily foreseeable in physics; a scientific revolution is predicted. Both physics and the concept of matter will have to change. This was Sellars’ view, though he thought that the change, in his case the move to pure processes, was already underway within physics. Naturalist dualism has much more recently been defended by, among others, Leopold Stubenberg, David Chalmers, and Galen Strawson. Chalmers argues that physics will have to take some “what it’s like” properties as primitives alongside the primitives of quantum mechanics, and predicts that laws will be discovered relating the two.
But the naturalist dualist position faces a number of objections. First, there is a problem about disciplinary authority. How might microphysicists be moved to posit Sellarsian sensa, or Chalmers’ “what it’s like” properties? Microphysicists do not study human behavior, or neural processing, or even the dynamics and kinematics of ordinary middle-sized inanimate objects. The proposed revision of physics is not motivated by the physical data that are the microphysicist’s proprietary evidence base. In effect, the physicist is being asked to do the philosopher a favor. For purposes of his philosophy of mind, Sellars needs physics to posit sensa. But even if the physicist is tractable and wants to reach out to a colleague across a disciplinary boundary, there is nothing he or she can do ex officio. The physicist is being asked to make a departmental commitment that he or she has no departmental authorization for making.
Second, it seems that in any case the details of microphysics should be irrelevant to philosophy of mind: Mental properties are determined by neuroanatomical properties, regardless of what constitutes the latter themselves. Changes in the physics underlying biology and chemistry should not matter in any way to the mind, however much they matter to matter. As J.J.C. Smart has put it:
[I]f it be granted that the brain is essentially a nerve net, then physics enters our understanding of the mind by way of the biochemistry and biophysics of neurons. But neurons are, in Feinberg's sense, “ordinary matter”. So whatever revolutionary changes occur in physics, there will be no important lesson for the mind-body problem or for the philosophy of biology generally ....The situation is not like that in the eighteenth century, when physics was mainly mechanics, and needed to be supplemented by the theory of electricity and magnetism, even for the purpose of understanding the behaviour of ordinary bulk matter.
Consider: If we were to take a collection of molecules, assumed to have just the properties they are thought to have at present, we could in principle build a version of a human organism whose behavior, including verbal behavior, would be just like ours under appropriately parallel circumstances. Would such a simulacrum not have a mind? Maybe not, but we would have every reason to think it did and no reason I can anticipate for denying that.
Third, the naturalist dualist faces a dilemma: If any reduction of mind to the natural order requires a reconception and expansion of physics to incorporate novel entities and principles not motivated by the physical data themselves, then either those entities and principles will be localized where we now take minds to be, viz., in central nervous systems, or like other entities and principles of fundamental physics they will pervade nature. But the former hypothesis, while coherent, is loony. Are the new entities and principles just shy? Why ever would the entities occur and principles apply only in regions of spacetime shaped like the heads of sentient creatures, or be specific to neural tissue, which regions and tissue are specified only at a level of organization far higher than that of microphysics? Why would their occurrence depend on their so much larger molecular environment? The notion is imaginable, but grotesque. And again, how could the microphysicist ex officio explain why the new entities occur just in the small and idiosyncratically distributed regions of spacetime where they do? (Nonetheless, Sellars firmly grasps this “shyness” horn of the dilemma.)
The second hypothesis, that the new entities and principles will pervade nature, is far more likely, but it encourages panpsychism, indeed is a form of it. If they are posited out of the need to reduce or explain mental phenomena, and they occur throughout nature, then so, presumably, do the mental phenomena. Chalmers cautiously defends this position”. [W]herever there is a causal interaction, there is information, and wherever there is information, there is experience” (The Conscious Mind, p. 297).
Considered as general metaphysics, panpsychism is hardly a popular choice, and many philosophers would think that for a naturalist dualist to be committed to panpsychism amounts to a reductio ad absurdum. But the dualist’s opponent cannot stop there with a good derisive snort. It is not as though the naturalist dualist has tacitly and unawares been committed to panpsychism; assuming the “shyness” horn of the dilemma has been rejected, the view the naturalist dualist has been defending by direct argument is a form of panpsychism. As I have said, I myself respect none of the arguments offered in support of naturalistic dualism, but it seems only fair at this stage to give some consideration to panpsychism itself, and see whether it does not deserve to be taken more seriously than it has been in the past century.
Classically, panpsychism has been the view that every individual thing in the universe has mental or psychological properties, an “inner” life. Human beings and animals are not alone in being conscious and/or thinking; plants, stones, drops of water, silicon compounds, molybdenum atoms, and even electrons are and/or do. The doctrine has been attributed, not always reliably, to such figures in the history of philosophy as Anaximenes, Plotinus, Francis Bacon, Leibniz, Spinoza, Schopenhauer, Schelling and Schiller. The most recent important philosophers to have held or recommended it were Hermann Lotze, Josiah Royce, and A.N. Whitehead. Lotze wrote: “All motion of matter in space may be explained as a natural expression of the inner states of beings that seek or avoid one another with a feeling of their need". The whole of the world of sense “ is but the veil of an infinite realm of mental life”. Royce: “Where we see inorganic Nature seemingly dead, there is, in fact, conscious life, just as surely as there is any Being present in nature at all”. Whitehead: “[Bacon’s view that] all bodies whatsoever, though they have no sense, ‘yet have perception’ expresses a more fundamental truth than do the materialistic concepts which were then being shaped as adequate for physics”. 
Some distinctions are needed. First, panpsychism is not Idealism, the view that all reality is mental and there are not really any physical objects. (It is not clear whether Leibniz” doctrine of monads made him a panpsychist or an Idealist. Lotze and Royce can be interpreted as Idealists as well.) Second, panpsychism is not and does not entail the thesis of a “World Soul,” though some panpsychists have accepted the latter thesis also. Third, panpsychism is not equivalent to “hylozoism,” the thesis that every individual thing is alive.
Fourth, there is a slightly weaker claim available to naturalist dualists: They may hold, not that every single individual thing that exists has mental properties, but only that mental properties pervade nature in the same way that quarks, leptons and their characteristic features do. For example, they might be properties of electrons only; it would not follow that pi-mesons or bosons had mental properties. I shall call this weaker position “Weak panpsychism”.
Attractive as they may have seemed to some, neither panpsychism nor Weak panpsychism is an easy position to defend. Early and unconvincing appeals were made to analogy, and to the slippery slope. Perhaps a better try was based on Bertrand Russell’s appeal to the intrinsic natures of unobservables in science. Russell pointed out that the unobservable entities studied by physics are known and described in purely relational terms, paradigmatically by their effects. For something to be an electron is just for that thing to do what an electron does. And it seems that scientific method limits us to such relational descriptions; science cannot tell us what an electron is like in itself, its intrinsic nature. Russell further argued that, come to think of it, much the same is true of ordinary observable macroscopic physical objects and their properties: prescientifically, we know and describe them ultimately only in terms of their effects on our sensory experience. Indeed, the only type of intrinsic nature we know is that of our sense experience itself, its “what it’s like” properties. Therefore, possibly, the intrinsic natures of subatomic particles and the like are “what it’s like” properties too, and panpsychism would follow. (Russell himself only suggests, and does not insist on, this last step.)
Two objections can be made against the Russellian argument. What grounds the assumption that the ultimate constituents of the physical world must have intrinsic properties at all? Perhaps the nature of a subatomic particle is exhausted by the totality of its relations to other things. Moreover, even if the “what it’s like” properties featured in sensory experience are the only intrinsic properties that we know directly and subatomic particles do have intrinsic natures, it hardly follows that the particles’ natures are “what it’s like” properties.
A tighter argument for panpsychism is suggested by Thomas Nagel. In section 2 above I spoke of “emergent” properties of things, but as philosophers use that term it has two senses, a weaker and a stronger. In the weaker sense, a property is emergent if it is possessed by a composite thing but not by any of that thing’s parts. For example, none of the parts of a ladder is itself a ladder, so the property of being a ladder is emergent in the weak sense. In the stronger sense, a property is emergent just in case it is emergent in the weaker sense but, in addition, the composite thing’s having it is not simply a matter of the thing’s parts being arranged in a certain way with respect to each other. The property of being a ladder is not emergent in the stronger sense, because for a thing to be a ladder is just for it to have serial rungs that are held together in parallel by longer side pieces.
Many philosophers have opined that emergence in the stronger sense is a metaphysical impossibility, in effect a case of something being created out of nothing. Or, at the very least, sound methodology forbids positing a strongly emergent property when one has any alternative at all. Now, suppose further that some mental properties cannot be reduced to physical properties of any sort, so that some version of property dualism is true. But mental properties are properties of composite beings such as ourselves, so if none of our ultimate parts have mental properties, our mental properties are strongly emergent. If strong emergence is impossible, then, it follows that some of our ultimate parts do have mental properties. Assuming that our ultimate parts are subatomic particles, it further follows that at least some of the particles of which we are made have mental properties. But those particles are of exactly the same kinds that pervade the universe; so mental properties pervade it as well.
Of course, this argument simply assumes property dualism, so at best it shows that if one is already a property dualist on independent grounds, one should be a panpsychist (at least a Weak one) as well. But the argument can be resisted even by the property dualist. He or she need not grant the assumption that our ultimate parts are subatomic particles. (Sellars’s argument for his sensa is an anti-emergence argument of just this sort; he argues that sensa are ultimate constituents of sentient beings.) Additionally, not everyone is so put off by the strong notion of emergence. C.D. Broad, for example, defended a strong emergentism at length.
The case for panpsychism is not powerful. I turn to the case against.
Panpsychism’s most obvious liability is the absence of scientific evidence: There is no scientific reason, as opposed to the foregoing philosophical arguments, for believing it, and it is a scientific claim. Recall the “disciplinary authority” problem for naturalist dualism: If molybdenum atoms have mental properties, that is for the microphysicist to find out. If microphysics has no need of the panpsychist hypothesis, we should apply Occam’s Razor.
The premise would be contested by certain interpreters of quantum mechanics (cf. note 16 above), who maintain that in order for there to be determinate physical fact in spatiotemporal region R, there is consciousness in R. And of course it is possible that such an interpretation might gain favor, so the present objection is hardly fatal. I would rejoin, though, that the interpretations in question are just that, interpretations of the quantum facts, not facts themselves, and the interpretation of quantum mechanics is considerably affected by philosophical considerations.
A more worrying difficulty for the panpsychist is the threat of epiphenomenalism. Because of the causal closure of physics, the panpsychist’s tiny mental properties could play no causal role. That is, since every nonrandom physical event has a sufficient physical cause, there is no work for the mental properties to do. They are brought into existence only to do nothing at all.
The latter conclusion is not inevitable. One could insist that some or all physical events are causally overdetermined, each one having both a sufficient physical cause and a sufficient or contributing mental cause. Perhaps there is a kind of mental-physical parallel in the world’s causal structure. The suggestion is ad hoc; different theorists will rate its plausibility differently.
For that matter, some panpsychists may not care if their mental properties are epiphenomenal, or indeed even see that as an objection. Assuming that there is a good reason for belief in epiphenomenal mental properties, then we should believe in epiphenomenal mental properties. But it is not quite so easy. Epiphenomenalism would reinforce the “absence of evidence” objection by making it a priori: If the panpsychist’s mental properties do not cause anything, how could they bring themselves to our attention? How could we possibly have scientific evidence of their existence?
A further difficulty for panpsychism generally is raised by Nagel’s anti-emergence argument. The mental properties we all know about are of course properties of complex organisms such as ourselves. If the anti-emergence argument is sound, those properties must be a function of the mental properties inhering in their subjects” ultimate components. How could that be? The question is bona fide, not rhetorical, for I know of no proof that my mental life could not be a function of the mental lives of my ultimate components, assuming arguendo that such exist. But it is hard to imagine. Suppose I am now simultaneously seeing a computer screen, feeling typing impacts on the tips of my fingers, hearing the slight whine of the air conditioner, suffering an ache in my left knee, hoping I will finish this paper before I leave the office today, and wanting a large gin and tonic. In what way could such a mental aggregate consist of a host of smaller mentations? Is it that some of my ultimate components are experiencing some of those very same mental states, and when enough of them do, I myself do? Or are the mental states of my components little, primitive states that somehow together add up to macroscopic states such as the ones I am in? (Note that the anti-emergentist would have to worry about strong emergence here.) Either alternative is hard to imagine, as is any further alternative.
Finally, if every individual thing has mental properties, what sorts of mental properties in particular do the smallest things have? It seems ludicrous to think that a molybdenum atom has either sensory experiences or intentional states. How could it see, hear, or smell anything? What would be the contents of its beliefs are desires? (Perhaps it wishes it were a silver atom.)
I close with a suggestion for the panpsychist, that will help alleviate that last problem. To say that the universe is suffused with mind is not to say that it is suffused with minds like ours. The mentation which is exhibited by inanimate things might, as Chalmers suggests, be rudimentary. Indeed, it might be minimal in a special way: it might be “pure” consciousness in the sense attributed to Buddhists and some Hindus. Reportedly, adepts can meditate themselves into a state of consciousness that is objectless, with no particular content. Perhaps, if panpsychism is true, that “pure” consciousness is the sort of mentation that electrons or molybdenum atoms have. That would nicely distinguish them and other inanimate things from those of us whose consciousness is contentful, and would release the panpsychist from having to wonder what molybdenum atoms feel or think about.
Now, I do not understand the idea of consciousness without content. And it would be a counterexample to Brentano’s thesis that all mental states are intentional (cf. note 25 above). But no wonder. The defenses of “pure” consciousness that I have heard rest on testimony about testimony of those who have themselves experienced the special meditative states. And that is where, or past where, Anglo-American philosophy of mind leaves off.
There would still be an emergence issue, this time about content. If my ultimate components are conscious but only objectlessly so, how then do my own mental states have intentional objects? But perhaps intentionality is easier to reduce to the physical than is consciousness.
As is probably obvious, I am no fan of dualism of any sort. But I have tried to explore the best way of being a mind-body dualist, and argued cumulatively that the best option is probably to be a Weak panpsychist. I only hope I have made no converts.
 Philosophers’ use of the terms “dualist” and “dualism” is local and topical, meaning only that the theorist in question thinks there are two distinct kinds of item in a given domain. The domain need not be all of reality, nor need one of the two kinds dominate the other in any sense, nor are there any normative implications, nor is the term itself pejorative. Philosophical mind-body “dualism” alleges only a duality, not a dualism in the sense that primarily concerned the “Light Against Darkness” conference and is elegantly expounded by Professor Fontaine in this volume. (Though, as Randall Styers shrewdly suggested in discussion, mind-body dualism in the philosophers’ sense can assume the aspect of, and even turn into, a dualism in one or another heavier and/or normative sense.)
 Wilbur D. Hart, The Engines of the Soul (Cambridge: Cambridge University Press, 1988); John Foster, The Immaterial Self (London: Routledge, 1996).
 Of course, it is possible to deny that the mind does causally interact with the body, though at horrendous cost in plausibility. For example, Leibniz held that minds and bodies merely run in parallel; there is a “pre-established harmony” engineered by God.
 Further: Minds are, unmistakably, in physical time; mental events occur in clear temporal relation to physical events. But physical time is only one of four coequal dimensions of physical spacetime. It is physically impossible for an entity to be in physical time without being in physical space as well.
 To say this is to suggest that Cartesian dualism is a theory of the mental, to be evaluated on its explanatory merits. That is not how Descartes himself conceived it. He knew very well that, considered as a theory, his dualism was both radical and radically unsatisfactory. Rather, he believed he had proved it to be true, by each of several deductive arguments. The first argument was epistemological, roughly that the mind is better known to its owner than is anything physical, hence the mind cannot be anything physical. A bit more precisely, any belief I have about anything physical can in principle be doubted, but my beliefs about my own present mental states are indubitable, hence my own present mental states are not physical. (This was not sound reasoning. Consider the fact that Lois Lane knew and always would know Clark Kent better than she could ever know Superman.) A better argument was based on the fact that the mind can be conceived or imagined as separate from the body. Descartes contended that what is imaginably separate must be actually distinct, though that inference is now generally rejected.
 See, e.g., Frank Jackson, Perception (Cambridge: Cambridge University Press, 1977); Frank Jackson, “Epiphenomenal Qualia”, Philosophical Quarterly 32 (1982):127-136.
 Psychologie vom Empirischen Standpunkt (Leipzig: Felix Meiner, 1924); see also Roderick M. Chisholm, Perceiving (Ithaca: Cornell University Press, 1957), 168-185.The term “intentional” as used here has nothing to do with action or intending to do something; it is from the Latin for to draw a bow at.
 “Empiricism and the Philosophy of Mind”, in The Foundations of Science and the Concepts of Psychology and Psychoanalysis (vol. I of Minnesota Studies in the Philosophy of Science; ed. Herbert Feigl and Michael Scriven; Minneapolis: University of Minnesota Press, 1956), 253-329; “Philosophy and the Scientific Image of Man”, in Frontiers of Science and Philosophy (ed. Robert Colodny; Pittsburgh: University of Pittsburgh Press, 1962), 35-78; “The Identity Approach to the Mind-Body Problem”, Review of Metaphysics 18 (1965): 430-51. But the term “naturalistic dualism” is David Chalmers’, who defends the doctrine in The Conscious Mind (Oxford: Oxford University Press, 1996).
 Pages 440 and 446 of “Seeing, Sense Impressions, and Sensa: A Reply to Cornman”, Review of Metaphysics 24 (1971): 391-447.
 In my talk at the “Light Against Darkness” conference I called them, respectively, “Weak naturalist dualism” and “Medium-Strength naturalist dualism”, but Ram Neta has persuaded me that that was inaccurate.
The Emperor's New Mind (New York: Penguin Books, 1989).Other quantum enthusiasts include David Hodgson (The Mind Matters (Oxford: Clarendon Press, 1991)), Henry Stapp (“Why Classical Mechanics Cannot Accommodate Consciousness But Quantum Mechanics Can”, Psyche 25 (1995) n.p. Cited July 1, 2003. Online: http://psyche.cs.monash.edu.au/v2/psyche-2-05-stapp.html.), and David Chalmers (The Conscious Mind), though Chalmers maintains a full bore naturalistic dualism, to be discussed below.
Of course, on some of its many interpretations, quantum mechanics is itself dualist as regards mind and body. I have in mind interpretations which appeal to “measurements” that cause collapses of the wave-function, and which further understand “measurements” in terms of the “consciousness” of an observer taken as primitive. For an informal exposition, see Eugene Wigner, “Remarks on the Mind-Body Question”, in The Scientist Speculates (ed. Irving J. Good; London: Heinemann, 1963), 284-302.
 Quentin Smith, “Why Cognitive Scientists Cannot Ignore Quantum Mechanics”, in Consciousness: New Philosophical Perspectives (ed. Quentin Smith and Aleksandar Jokic; Oxford: Oxford University Press, 2003), 409-46, and Michael Lockwood, “Consciousness and the Quantum World: Putting Qualia on the Map”, in the same volume, pp. 447-67.
 Kirk Ludwig makes a similar point specifically against Stapp, in “Why the Difference Between Quantum and Classical Physics is Irrelevant to the Mind/Body Problem”, Psyche 25 (1995) n.p. Cited July 1, 2003. Online: http://psyche.cs.monash.edu.au/v2/psyche-2-16-ludwig.html.
 “Epiphenomenal Qualia”.
 For that matter, Descartes’ original epistemological arguments (note 9 above) would similarly be unaffected by the move to quantum mechanics.
 “Linguistics and Cognitive Science: Problems and Mysteries”, unpublished, pp. 1-2.(A published version of this paper appears in The Chomskyan Turn (ed. Asa Kasher; Oxford: Basil Blackwell, 1991), but omitting the section quoted.)For developments of the same idea, see also Tim Crane and D. H. Mellor, “There is no Question of Physicalism”, Mind 99 (1990): 185-206, and Barbara Montero, “The Body Problem”, Noûs 33 (1999): 183”200.
It should be noted that Chomsky himself is not a declared dualist of any sort; he is only making room for such a position. However, a further passage suggests an even stronger stance:
[The terms] “body” and “the physical world” refer to whatever there is, all of which we try to understand as best we can and to integrate into a coherent theoretical system that we call the natural sciences ....If it were shown that the properties of the world fall into two disconnected domains, then we would, I suppose, say that that is the nature of the physical world, nothing more, just as if the world of matter and anti-matter were to prove unrelated.
(“Linguistics and Cognitive Science”, pp. 38”39.)
 Brentano maintained that “intentionality” or aboutness is the mark of the mental, that all and only mental items have it. (Which thesis is quite controversial in each direction. But I agree that all mental items are intentional; see Consciousness and Experience (Cambridge, MA: Bradford Books / MIT Press, 1996).)
 Leopold Stubenberg, Consciousness and Qualia (Amsterdam: John Benjamins, 1998); Chalmers, The Conscious Mind; Galen Strawson, “The Self”, Journal of Consciousness Studies 4 (1997): 405”28.
 Notice that the quietist quietly ducks this issue. Every quietist should be asked, “Are you willing to work with what physicists posit on their own initiative, or might you have to ask them for favors?”
 “The Content of Physicalism”, Philosophical Quarterly 28 (1978): 339”41.
 In ”Why Cognitive Scientists Cannot Ignore Quantum Mechanics”, Quentin Smith rebuts a similar argument, but not quite this one.
I made a related argument against Sellars in Consciousness, p. 103, in terms of the determination of nature’s higher levels of organization by its lower ones. Roughly: Since molecules are made of atoms, molecular facts are determined by already familiar microphysical facts; biological facts are determined by molecular facts plus ordinary macroscopic surroundings; psychological facts are determined by biological facts plus ordinary macroscopic surroundings; so, given transitivity of determination, psychological facts are determined by microphysical facts of the sort that are already fairly well known.
 Or so he told me in 1979, during the Mini-Conference on Wilfrid Sellars’ Theory of Perception, Ohio State University, when I had pressed the present dilemma upon him and urged that pervasiveness was better than shyness. During lunch at a restaurant later on, Sellars suddenly buttonholed the waiter and (without preamble) exclaimed, “Lycan here thinks stone walls have orgasms!”
 Against Sellars, Chapter 8 of Consciousness, sections 5-10; against Chalmers, “Vs. a New A Priorist Argument for Dualism”, in Philosophical Issues 13 (ed. E. Sosa and E. Villanueva; Oxford: Basil Blackwell, 2003).
 The World and the Individual (New York: Macmillan, 1901), 2:240.But it is not clear that Royce extended mentality to the ultimate individual constituents of matter.
 Microcosmus (trans. Elizabeth Hamilton and E.E.C. Jones; Edinburgh: T&T Clark, 1899), 1:363.
 Unless I have missed it, Michael Rosenthal takes no stand on this in his contribution to this volume. The Ethics contains a passage, Book 2, Prop. 7, scholium, that reads, [W]hether we conceive nature under the attribute of Extension, or under the attribute of Thought ... we shall find one and the same order, or one and the same connection of causes ...” (in The Collected Works of Spinoza (ed. and trans. E. Curley; Princeton: Princeton University Press, 1677/1985), 451; cited by William Seager in “Panpsychism”, The Stanford Encyclopedia of Philosophy (ed. Edward N. Zalta; Summer 2001) n.p. Cited July 1, 2003. Online: http://plato.stanford.edu/archives/sum2001/entries/panpsychism/.The latter survey article is an excellent guide, as was its predecessor, Paul Edwards’ “Panpsychism”, in The Encyclopedia of Philosophy (ed. Paul Edwards; New York: Macmillan, 1967), 6:22-31, though I have some disagreements with each.
 Science and the Modern World (New York: Macmillan, 1954), 60-61.But it must be remembered that Whitehead embraced an ontology of pure processes, not of individual things.
 Notice, incidentally, that panpsychism as defined above does not actually entail dualism; one could accept it but also maintain that all mental properties are reducible to physical ones, though I have never heard of anyone’s taking that position.
 In Mind, Brain and the Quantum, Lockwood makes a version of this argument, though he is not a naturalist dualist.
 “Panpsychism”, in Mortal Questions (Cambridge: Cambridge University Press, 1979), 181-195.
 The Mind and Its Place in Nature (New York: Harcourt, Brace, 1925).
 This objection need not bother the panpsychist who makes no appeal to the anti-emergence argument. For such a person is free to reject the idea that my mentation is a function of the mental states of my components, and can suppose it is unrelated. That suggests the zany possibility that various parts of my body, such as my right foot, my upper teeth, the small of my back, or my right forearm, wrist and hand are all experiencing distinct and unrelated mental lives. Chalmers takes much this position, though with a few qualifications, one of which is that very simple systems would have very simple phenomenology or protophenomenology, so simple that they would fall short of having what we usually think of as minds (The Conscious Mind, pp. 298”99).
 A side issue: The object of meditating and presumably that of achieving “pure” consciousness is psychological and/or spiritual benefit. Pure consciousness is good for you. So if molybdenum atoms have pure and only pure consciousness, they are probably quite happy as they are.