Whitehead and the Revival (?) of Panpsychism
Whitehead’s philosophy is of perennial scholarly interest as one of the relatively few really serious attempts at a systematic metaphysics. But unlike almost all major ‘philosophical systems’ it is not merely an historical curiosity, but retains contemporary supporters actively deploying Whitehead’s viewpoint in discussion of a variety of live philosophical problems. Furthermore, Whitehead’s metaphysics is the sole example of a comprehensive philosophical system which aims to take into account the radical transformation of science which occurred at the beginning of the twentieth century with the development of relativity and quantum mechanics, developments with which Whitehead was, as a first rate mathematician, highly familiar.
On the other hand, there is no denying the daunting character of Whitehead’s writing. Many philosophers steeped in the analytic tradition regard the very idea of systematic philosophy as deeply suspicious and regard the labyrinthine difficulty of Whitehead’s system as evidence of what they see as the empty verbiage and obscurantism of traditional metaphysics. Thus, amongst modern analytic philosophers, Whitehead is little read.
Modern philosophical and scientific sensibility also professes to find some of Whitehead’s core doctrines fundamentally wrong-headed, most especially the panpsychism – the idea that mentality is a fundamental or ‘primitive’ feature of reality of which everything partakes in some measure and in some way. Whitehead himself never used the term ‘panpsychism’ to describe his own views so far as I know (see Hartshorne 1950). Perhaps he did not wish readers to draw conclusions about his own doctrines based upon association with earlier panpsychists, such as Gustav Fechner or Josiah Royce, whose extravagant if poetic discussions of plant and planet consciousness cast a certain shadow of disrepute on the view (see Seager 2001 for a brief discussion of various forms of panpsychism).
It may also be that Whitehead wanted there to be no confusion about his attitude towards consciousness, which he did not think was a ubiquitous feature. When explicating his notion of prehension by appeal to Leibniz’s distinction between perception and apperception Whitehead warns the reader that “these terms are too closely allied to the notion of consciousness which in my doctrine is not a necessary accompaniment” (AI, 234). Whitehead’s reticence about consciousness may come down to little more than a verbal matter. Leibniz’s notion of apperception is a kind of self-consciousness or introspective consciousness: “... it is well to make the distinction between perception which is the internal state of the monad representing external things, and apperception, which is consciousness, or the reflective knowledge of this internal state” (1714/1989, p. 208). Perhaps echoing this feature of Leibniz’s conception (while at the same time strongly repudiating the traditional account of perception as a mental act directed at internal representations), Whitehead says that “consciousness concerns the subjective form of a feeling” (PR, 282). This is not an unreasonable interpretation of the term ‘consciousness’, but a more compendious, and perfectly commonplace, definition of consciousness would allow feelings themselves to count as states of consciousness, for they are subjective qualitative states. Such a notion underlies the seemingly undeniable fact that animals are fully conscious beings even though they may entirely lack any form of self-awareness and be utterly oblivious to their own mental states as such (they remain for all of that fully conscious of various aspects of the world, notably including, of course, their own bodies). It makes little difference how we interpret the word ‘consciousness’ so long as we are aware of this distinction (it is perhaps to forestall confusion on this point that David Griffin (1998) advocates use of the term panexperientialism to characterize Whitehead’s, and his own, position).
Nonetheless, there can be no doubt that Whitehead was a panpsychist insofar as he regarded the fundamental ‘units’ of existence as in some way experiential. A vivid example is his remark that “each actual entity is a throb of experience including the actual world within its scope” (PR, 220)). Whitehead is in fact undoubtedly the foremost exponent of panpsychism in the twentieth century.
What is of interest to me here is that one of the core reasons Whitehead had for espousing panpsychism is one that has currently resurfaced within the writing of analytic philosophers of consciousness. I cannot speak as an expert on Whitehead, but I think it is worth briefly exploring the reappearance of this argument along with the somewhat curious absence of any – or at least very little – reference to Whitehead’s own work.
Lately, the problem of consciousness has been exercising analytic philosophers of mind as a special problem deserving of its own treatment in any account of the mind. The sense of ‘consciousness’ which is at issue is that of bare subjective feeling, the second interpretation of the term I offered above. The backdrop of the problem is the philosophical task of naturalizing the mind, which many take to be crucial for the completion of a ‘scientific metaphysics’ and which is supposed to be accomplished via the successful integration of mind into our scientific picture of the world. Philosophers have taken it as given that the scientific picture is fundamentally a materialistic or physicalistic picture and thus the project of naturalization is that of showing how mind and consciousness can be explicated in physicalistic terms.
Over some decades now, a very large number of such approaches have been attempted, far from exhaustively including variant forms of central state identity theory (e.g. Armstrong 1968, Hill 1991), pscyho-functionalism (e.g. Putnam 1967, Lewis 1966, Lycan 1987), anomalous monism (Davidson 1970), eliminative materialism (Churchland 1981), representational theories (e.g. Dretske 1995, Tye 1995). It is fair to say that although all these accounts retain enthusiastic proponents, none of them have succeeded in dispelling the mystery of consciousness. All of these theories go a fair ways – and this is an undeniable accomplishment – towards showing how the complex behavior, including the ‘internal’ behavior of computational processes, characteristic of creatures possessed of minds might fall under a high level theory which is amenable to naturalization, but they all struggle to show that such a system would, necessarily and in virtue of it physical organization, have any feelings or states of consciousness.
This particular puzzle of consciousness per se was eloquently forced upon us by Thomas Nagel’s famous paper ‘What is it Like to be a Bat’ (1974). But in a less well known paper, Nagel rather diffidently ventured a kind of solution to the puzzle – panpsychism (1979). In brief compass (and somewhat modified) the argument goes as follows. Under the constraint of physicalistically acceptable naturalization, there is no form of emergentism which can account for consciousness. For the only sort of naturalistically acceptable emergentism is one in which there are only adventitious epistemological barriers to understanding how the emergent phenomena arise from the interaction of the ultimately purely physical components – whatever physics will finally reveal them to be – of the system under study. It is only to be expected that basic physics will never produce a description of the brain (plus environment) of a thinker which could illuminate, predict or explain that thinker’s mentalistically describable behavior, but this is ‘merely’ a problem of complexity, albeit one that studies in complex systems shows can never be overcome by advances in computational machinery or data measurement. However, Nagel argues that consciousness cannot be thus ‘reduced’ to the complex interaction of a system’s parts and therefore is not a merely epistemologically emergent phenomenon. Now, if consciousness is not something which emerges out of the relations of material structures, it must exist independently of those structures (if it exists at all, but the outright denial that consciousness exists is absurd and not even the so-called eliminative materialists have gone that far). There are many ways to understand such independent existence, but Nagel wishes to retain a connection between and integration with the physical world as revealed by science. This desire rules out views which make the material world a kind of illusion, such as idealism and also forces the rejection of dualism, with its merely contingent, and in itself utterly mysterious, relation between matter and consciousness. The position that remains is panpsychism – mind is a fundamental and primitive feature of the physical building blocks of reality.
Nagel’s is an interesting argument. I do not intend to consider here the plausibility of its premises, which all involve deep, difficult and controversial philosophical questions. But it must be noted that Nagel neglects to even consider the possibility of a more radical, non-epistemological, form of emergentism such as that envisaged by Morgan (1923) or Broad (1925), in which novel existents possessing new and proprietary causal powers emerge out of the simple, and entirely physical, basis of the world. It may be that Nagel could effectively reply that modern physical theory strongly suggests that the world is closed under physical causation because of, for example, fundamental conservation laws which preclude the existence of any novel and independent causal powers. Furthermore, any form of radical emergentism suffers from a problem highlighted by the nature of Nagel’s own argument. For notice that the argument is of an a priori form, and despite purporting to show that panpsychism must be true, it leaves us with no understanding of how panpsychism could be true. Nagel is only too aware of this difficulty, remarking that panpsychism has “the faintly sickening odor of something put together in the metaphysical laboratory” (1986, 49). But it seems that a radical emergentism would similarly leave us necessarily bereft of any account of how emergence could work.
But another argument in favor of panpsychism intrudes here which might help with this difficulty, and returns us to Whitehead’s thought. We might call this the ‘intrinsic nature’ argument for panpsychism. It can be approached via some remarks of Whitehead’s outlining the (in his view mistaken) traditional scientific and thence commonsensical understanding of the nature of matter itself. In Modes of Thought (1938, 131 ff.) Whitehead characterizes this “common-sense” notion of matter as “bits” which are “enduring self-identically”. Each such bit “occupies a definite limited region” and possesses its own set of intrinsic properties such as “its mass, its colour” and the “essential relationship between bits of matter is purely spatial” and space is “unchanging, always including in itself this capacity for the relationships of bits of matter”. Whitehead goes on to proclaim that “this is the grand doctrine of nature as a self-sufficient meaningless complex of fact. It is the doctrine of the autonomy of physical science”.
It is evident that this doctrine is precisely that which underlies the project of naturalization outlined above and which Nagel argues founders on the problem of the emergence of consciousness. Whitehead’s description of the doctrine of the autonomy of physical science also suggests that the problem lies with the presumed inert, passive or ‘empty’ nature of matter. On this view, there is nothing about matter which can even begin to explain how anything like a conscious experience could arise out of its interactions, whereas it does seem explicable, at least in principle, how various complex behaviors of systems of material parts could arise. In fact, we might take the opposition between behavior and experience as definitive of the problem here. Behavior generation can be explicated in terms of the merely dispositional properties of matter to react in certain specifiable ways under specifiable conditions.
For example, one apparently basic property of matter recognized by modern science is the so-called spin angular momentum of certain elementary particles. This property has certain functional analogies with the angular momentum we are familiar with in the behavior of macroscopic objects. For example, the spin of a proton explains its magnetic properties and hence the observed fine splitting of certain spectroscopic lines. But in other respects spin is quite unlike ordinary angular momentum. Only certain discrete values are allowed, for instance, and these values appear no matter what ‘spin axis’ we measure. The point here is that ‘spin’ is defined solely in dispositional terms. What ‘spin’ actually is remains quite mysterious (save for the aura of often misleading meaning drawn from the analogy with the everyday world). Whitehead describes this purely dispositional analysis as a matter of regarding the basic elements of material reality “in abstraction from everything except what concerns their mutual interplay in determining each other’s historical routes of life-history”. This picture leaves the laws of physics as exhausted by “the laws declaring how the entities mutually react amongst themselves”, an impoverished outlook resulting from the way “science has abstracted from what the entities are in themselves” (1925, 106).
Such abstraction is problematic because it is arguable that any disposition must be grounded in some intrinsic nature, and our failure to take this into account leaves us in irredeemable ignorance about the most fundamental features of the world. Whitehead described the predicament thus: “all modern ... cosmologies wrestle with this problem. There is, for their doctrine, a mysterious reality in the background, intrinsically unknowable by any direct intercourse” (1933, 133). Whitehead, following Leibniz in certain respects, asserts both that matter must indeed possess an intrinsic nature, and that there is only one such nature with which we are familiar: experience. Whitehead praises Leibniz, in a phrase reminiscent of Nagel’s worry about consciousness, for explaining “what it must be like to be an atom” (1933, 132).
I suppose one might regard the jump from the premise of matter’s requiring an intrinsic nature to the conclusion that some form of mentality provides the requisite intrinsic nature as rather too great a leap. One might instead appeal to Occam’s razor and demand that matter’s intrinsic nature be confined to no more than is required to underwrite the kind of behavioral dispositions which are codified in basic physical law. While possessing the merit of modesty, such a suggestion is somewhat odd. For we have no conception whatsoever of any such ‘minimal’ intrinsic nature after all and this suggestion therefore simply leaves us mired in the same mystery with which we began. Occam’s razor generally applies to competing explanations, so it is a rather unorthodox use of the principle to favor an intentionally contentless and entirely unarticulated conception of matter’s intrinsic nature over Whitehead’s hypothesis.
Furthermore, whatever intrinsic nature we might settle on, one of its explanatory functions is to integrate mentality itself (especially consciousness) into a world of matter. The panpsychist alternative appears to offer some hope of such integration. The defender of the Occamite approach can do no better than offer yet another promissory note here and one that looks particularly difficult to cash. If matter’s intrinsic nature is to be limited to only the capability of producing matter’s behavioral dispositions then we are going to be left with exactly the original mystery of consciousness, with no more prospect of its solution than before.
In any case, from this radical starting point, Whitehead elaborates his full metaphysics, which it is not for me to expound upon. I want rather to note the way that this starting point has once again forced itself upon some recent philosophers of mind (with, it must be said, little or no recognition of Whitehead’s earlier efforts). There is a palpable reluctance among analytic philosophers to give serious attention to panpsychism, doubtless because panpsychism seems radically unscientific – empty of empirical content. The initial hint that a radical transformation in our conception of matter might be required to solve the problem of consciousness thus comes in a more circumspect guise. This is the hypothesis that perhaps what is needed before a scientific account of consciousness might be possible is nothing less than a revolution in basic science.
Such an hypothesis is broached by a number of prominent thinkers. In a recent volume, Noam Chomsky argues that, in general, the vaunted unifying power of modern science has been bought at the cost of radical transformation in science itself (2000, 82 ff.). In an interesting analysis, Chomsky reminds us that it was Newton himself who effectively destroyed the purely mechanical view of the world with his introduction of gravitational forces as products of some intrinsic property of matter, whose nature Newton professed utterly mysterious (and which greatly troubled him with its apparent power to act at a distance). Chomsky takes this to be a general rule of scientific progress, which may be invoked yet once more in the face of the problem of consciousness. Chomsky elsewhere slides closer to Whitehead’s own doctrines where he approvingly quotes Priestley’s remark that matter “ought to rise in our esteem, as making a nearer approach to the nature of spiritual and immaterial beings” (2000, 113). It must be admitted that Chomsky goes on to suggest that ultimately some kind of emergentism is the proper approach to the mind, but as I have tried, in some measure at least, to argue above: what alteration in the notion of matter can we conceive which will explicate the emergence of consciousness save the panpsychist hypothesis? Chomsky does not say. It is simply leaving the mystery untouched to demand a revolution in science after which it will be ‘evident’, ‘obvious’ or merely ‘uncontroversial’ that “... ‘the powers of sensation or perception or thought are’ are properties of ‘a certain organized system of matter’...” (2000, 113).
Another such reluctant thinker is John Searle, long a champion of the professedly straightforward but in truth rather murky idea that ‘consciousness is a biological phenomenon’, who likens our current state of scientific knowledge of mentality to that of physics prior to the nineteenth century introduction of electromagnetic fields (and the idea of fields in general) by Clerk Maxwell. Conscious seems materialistically inexplicable, says Searle, “because we do not know how the system of neurophysiology/consciousness works, and an adequate knowledge of how it works would remove the mystery” (1992, 102). Searle evidently does not regard the puzzle of consciousness as one that can be solved by standard methods in biology (or any other science). What sort of features of neurophysiology, for example, are we ignorant of that go beyond the admittedly vast details of neural signaling and organization? This is not to say that Searle favors the panpsychist option. Far from it. He has heaped scorn on the doctrine as an “absurd view” (1997, 48). But, again as we have seen, the perception that a revolution in science is needed before consciousness can be accommodated within it really stems from the prior perception that the dispositional properties of matter as currently understood are simply inadequate to explain how matter could generate experience. And the nature of the problem leaves it entirely unclear how adding some additional non-mentalistic dispositional powers to matter could transform our understanding enough to make the generation of consciousness from matter explicable.
In fact, Searle’s infamous Chinese Room thought experiment (1980) can be regarded as, or adapted into, a kind of refutation of the idea that any purely dispositional analysis of matter could explain consciousness. For such an analysis is perfectly analogous to the computer program model of the mind insofar as the latter analyses mind as merely a set of dispositions to produce certain behavior in certain circumstances. If Searle’s thought experiment is effective against traditional computationalist theories of mind, than a computer program written to simulate the basic dispositions of matter would seem no more capable of explaining how mind emerges. Searle in fact comes very close to making this very point in his discussion of the so-called brain simulation reply to the thought experiment. I am suggesting that we can understand Searle’s appeal to the ‘causal powers’ of neurophysiology as not simply an appeal to the laws of neural operation which are entirely dispositional in nature, but rather as an appeal to the nature of neurons, or ultimately the matter which forms them, which underlies these laws.
Yet another ‘revolutionist’ is the famous mathematician and physicist, Roger Penrose, who expects that some heretofore undiscovered interaction of gravitational and quantum physics will permit the brain to exceed the computational boundaries of standard mathematics, and standard computers, (see Penrose 1989, 1994) and thus account for certain otherwise inexplicable aspects of mentality, especially of mathematical thought (the relation to consciousness in Penrose’s thought is not altogether clear). I will not attempt either to describe or criticize Penrose’s ideas here, but will note that he, along with his sometime collaborator Stuart Hameroff, have at least sometimes given interpretations of their views that suggest a panpsychist view of nature (see Hameroff and Penrose 1996).
Beyond the revolutionists, there are philosophers who have come at least very close to positively endorsing some kind of panpsychist alternative and have done so, at least in part, because of the difficulty about matter’s intrinsic nature which I have outlined. Two prominent examples are Michael Lockwood (1991) and Galen Strawson (1994, 1997/1999). As is entirely typical, neither makes any reference to Whitehead, while coming to conclusions that are very similar to certain basic aspects of some of Whitehead’s core doctrines. Lockwood appeals to Russell’s notion of the ‘inscrutability of matter’ as one ground for a reworked conception of matter which is at bottom panpsychist, where the inscrutability at issue is our familiar idea that the scientific conception of matter reveals nothing of its intrinsic nature. Lockwood proposes instead that “the physical world must have an intrinsic nature ... [and], in consciousness, that intrinsic nature makes itself manifest” (1991, 238). Lockwood’s completed scheme then takes reality as, in total, a “sum of perspectives” (1991, 177).
Strawson’s approach is broadly similar to Lockwood’s, including the nod towards Russell’s work. Strawson regards his view as a form of physicalism, in the sense that matter’s nature is to be revealed as, in part, essentially mentalistic. As he puts it: “the experiential considered specifically as such – the portion of reality we have to do with when we consider experiences specifically and solely in respect of the experiential character they have for those who have them as they have them – that ‘just is’ physical” (1997/1999, p. 7). Strawson also suspects that the integration of such a view of physical reality will require a revolutionary transformation of physics, and thus he joins the ranks of the revolutionists discussed above, with the crucial difference that he comes much closer to embracing the conclusion that only allowing matter itself to have a mentalistic intrinsic nature will provide a potential solution to the problem of consciousness. Nonetheless, and despite accepting panpsychism as a genuine option, Strawson also expresses the usual reluctance to endorse it, preferring to maintain that his view is suggestive of and compatible with panpsychism but not equivalent to it (see 1994, pp. 75-77). That is, Strawson accepts without reservation that the mental is a fundamental feature of the world, but withholds judgment about whether it is ubiquitous. It is difficult to see, however, how Strawson’s remarks about the nature of the physical could underwrite an account of consciousness unless some kind of panpsychism is adopted; otherwise the problem of emergence remains untouched. And note that if this problem can be solved so as to provide an acceptable explanation of the emergence of the experiential from the non-experiential, then why not let that account stand for the whole story about the emergence of mind from a ‘radically non-experiential’ physical world; that is, why not adopt a standard form of materialism? Perhaps Strawson would be willing to regard the fact that certain physical structures possess consciousness even though their components are entirely non-experiential as itself a fundamental feature of reality, or a basic natural law. The matter-consciousness link would then be a brute fact, inexplicable despite the rich set of correlations between material structures and states of consciousness which are becoming so evident in neurophysiological studies. Panpsychism seems to offer some advantage here. While it does of course assert that mentality is fundamental, the fact that it is ubiquitous offers the chance to explain how complex minds arise out of material interactions insofar as those interactions partake themselves of some form of mentality. This option puts the brute facts at the right level, so to speak, which is down among the most basic features of reality.
This same reluctance to endorse panpsychism is found in the final philosopher I shall exhibit here. David Chalmers is largely responsible for the most recent rekindling of interest in the search for a scientific account of consciousness and is well known for coining the catch phrase ‘the hard problem of consciousness’ to refer to the specific problem we have been discussing. Of all the writes considered here, Chalmers is the most willing to consider panpsychism a serious option, and offers several arguments that lend some support to the doctrine. His principal argument is not the intrinsic property argument that has concerned us here, but rather an argument from the fundamentalness of information in the world, and our basic theories of it, allied with the somewhat tentative additional premise that information is, at bottom, tied to mentality, to the conclusion that mind is a basic feature of reality (see Chalmers 1996, ch. 8; for another information based argument explicitly in support of panpsychism see Seager 1995). But Chalmers also considers the intrinsic property argument and notes that it presents the “threat of panpsychism” (1996, 154). He immediately adds that perhaps this ‘threat’ is not “such a bad prospect”. Like Strawson, Chalmers asserts that while his view requires that mentality (at least consciousness) be a fundamental feature, it does not have to be ‘spread out’ in the world in the way panpsychism envisions. He says that an alternative to a panpsychist account of mind would be such that “the relevant properties [i.e. the properties which account for the generation of phenomenal consciousness] are protophenomenal properties”, but then naturally has to admit that these protophenomenal “intrinsic properties are quite foreign to our conception” and must perform a task beyond the capabilities of “standard physical properties” (1996, 154). Once again, we can see that the basic problem – attributing any entirely non-mentalistic intrinsic nature to matter – seems simply to leave us facing the original problem of consciousness, since we neither have any idea of what such an intrinsic property might be, nor, if it is non-mentalistic, how it could underlie more than the physical dispositional properties of matter evinced in the ordinary laws of physics (save by the unhelpful stipulation that this mysterious intrinsic property is sufficient to generate experience).
These examples suggest something of a trend. The problem of the ultimate nature of matter is inextricably linked to the problem of consciousness. All the thinkers canvassed above agree on some version of this thesis. It is also one of Whitehead’s core insights. Whitehead took the next step of embracing a panpsychist conception of matter as necessary for an explanation of mind which could be integrated with, and indeed, help make sense of, the expanding scientific account of the world. Most modern thinkers, save for his own followers, are reluctant to follow Whitehead this far, but therefore find themselves mired in a problem of consciousness which seems utterly intractable. Furthermore, these thinkers also pay little or no attention to Whitehead’s own writings. It is hard to say whether analytic philosophers could, after so many years of neglect, find anything in Whitehead they could adopt or adapt to their style of philosophizing, but I would suggest that in the face of the evident difficulty of the problem of consciousness and the apparent convergence of several lines of argument towards some of Whitehead’s most fundamental ideas, that it is time to have a serious look at Whitehead’s approach to the mind-matter problem.
University of Toronto at Scarborough
Armstrong, D. (1968). A Materialist Theory of the Mind, London: Routledge and Kegan Paul.
Broad, C. (1925). The Mind and Its Place in Nature, New York: Harcourt, Brace.
Chalmers, D. (1996). The Conscious Mind: In Search of a Fundamental Theory, Oxford: Oxford University Press.
Chomsky, N. (2000). New Horizons in the Study of Language and Mind, Cambridge: Cambridge University Press.
Churchland, P. (1981). ‘Eliminative Materialism and Propositional Attitudes’, Journal of Philosophy, 78, pp. 67-90.
Davidson, D. (1970). ‘Mental Events’, in L. Foster and J. Swanson (eds.) Experience and Theory, University of Massachusetts Press. Reprinted in Davidson’s Essays on Actions and Events, Oxford: Oxford University Press, 1980.
Dretske, F. (1995). Naturalizing the Mind, Cambridge, MA: MIT Press.
Griffin, D. (1998). Unsnarling the World Knot: Consciousness, Freedom and the Mind-Body Problem, Berkeley: University of California Press.
Hameroff, S. and Penrose, R. (1996). ‘Conscious Events as Orchestrated Spacetime Selections’, in The Journal of Consciousness Studies, 3 (1), pp. 36-53.
Hartshorne, C. (1950). ‘Panpsychism’, in A History of Philosophical Systems, V. Ferm (ed.), New York: Rider and Company, pp. 442-453.
Hill, C. (1991). Sensations: A Defense of Type Materialism, Cambridge: Cambridge University Press.
Morgan, C. (1923). Emergent Evolution, London: Williams and Norgate.
Leibniz, G. (1714/1989). Monadology, in G. W. Leibniz: Philosophical Essays, R. Ariew and D. Garber (eds. and trans.), Indianapolis: Hackett Publishing Company.
Lewis, D. (1966). ‘An Argument for the Identity Theory’, in the Journal of Philosophy, 63, pp. 17-25. Reprinted in Lewis’s Philosophical Papers, vol. 1, Oxford: Oxford University Press, 1983.
Lockwood, M. (1991). Mind, Brain and the Quantum, Oxford: Blackwell.
Lycan, W. (1987). Consciousness, Cambridge, MA: MIT Press.
Nagel, T. (1974). ‘What is it Like to be a Bat?’, Philosophical Review, 83, pp. 435-50. Reprinted in Nagel’s Mortal Questions, Cambridge: Cambridge University Press, 1979.
Nagel, T. (1979). ‘Panpsychism’, in Nagel’s Mortal Questions, Cambridge: Cambridge University Press, 1979.
Nagel, T. (1986). The View from Nowhere, Oxford: Oxford University Press.
Penrose, R. (1989). The Emperor’s New Mind, Oxford: Oxford University Press.
Penrose, R. (1994). Shadows of the Mind, Oxford: Oxford University Press.
Putnam, H. (1967). ‘The Nature of Mental States’, in W. Capitan and D. Merrill (eds.) Art, Mind and Religion, Pittsburgh: University of Pittsburgh Press. Reprinted in Putnam’s Mind, Language and Reality (Collected Papers, vol. 2), Cambridge: Cambridge University Press, 1975.
Seager, W. (1995). ‘Consciousness, Information and Panpsychism’, in the Journal of Consciousness Studies, 2, pp. 272-88.
Seager, W. (2001). ‘Panpsychism’, in the Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/.
Searle, J. (1980). ‘Minds, Brains and Programs’, Behavioral and Brain Sciences, 3, pp. 417-24.
Searle, J. (1992). The Rediscovery of the Mind, Cambridge, MA: MIT Press.
Searle, J. (1997). ‘Consciousness and the Philosophers’, in The New York Review of Books, 44 (4), pp. 43-50.
Strawson, G. (1994). Mental Reality, Cambridge, MA: MIT Press.
Strawson, G. (1997/1999). ‘The Self’, in The Journal of Consciousness Studies, 4 (5/6), pp. 405-28. Reprinted in S. Gallagher and J. Shear (eds.) Models of the Self,Thorverton: Imprint Academic, 1999 (my page references are to Gallagher and Shear).
Tye, M. (1995). Ten Problems of Consciousness: A Representational Theory of the Phenomenal Mind, Cambridge, MA: MIT Press.
Whitehead, A. N. (1925). Science and the Modern World, New York: MacMillan.
Whitehead, A. N. (1929). Process and Reality, New York: MacMillan.
Whitehead, A. N. (1933). Adventures of Ideas, New York: MacMillan.
Whitehead, A. N. (1938). Modes of Thought, New York: MacMillan.