The Conscious Mind: In Search of a Fundamental Theory (Philosophy of Mind) Revised ed. Edition

I admit up front I'm a Chalmers fan and that is not to say that I agree with his many of his speculations concerning properties of the universe yielding consciousness. I like the way Chalmers angles at a subject and explores objections to his view at every step of the process. He does incorporate certain assumptions he fails to explore however and they turn out to be significant.

This is Chalmers' first book (1997) on consciousness, a subject he reprises in 2010 with "The Character of Consciousness" a book I reviewed some time back. In some ways, this book is a clearer exposition than the reprise. The subject matter is more clearly divided. In the first part of the book he argues that materialism must be false because consciousness does not logically supervene on physical process though it does "naturally supervene" on them. His arguments here are carefully crafted and reasonably convincing. He pays careful attention to distinguishing consciousness (the "what it is like to be" nature of subjective experience) from psychological or cognitive states. He is a little to quick here to define this line so sharply but he uses this clean distinction to get a handle on why it is so difficult to connect brain states directly to the subjective experience of consciousness. This line of argument leads Chalmers to a "property dualism" in which a new phenomenon, consciousness that is real but not physical nevertheless emerges from the physical, that is the causally closed physics of modern science. He uses the second half of his book, less persuasively, to propose a speculative solution. So how does this all go?

Chalmers posits a set of psychophysical or phenomenal laws in parallel with physical laws. These other laws are not merely aspects of physical law which physicists have not yet discovered (along lines of Thomas Nagel's "anomalous monism"). Rather they are a complete set of laws, independent of the physical that happen to exist in parallel with it. They are undetectable by physics and moreover they really do not have any effect on the evolution of the universe until the right kind of organization happens to come along (something that might not have happened)at which time they serve to connect up with the physical organization to evoke the new phenomenon of mind.

Chalmers glibly assumes that the laws of physics and the psychophysical are eternal. This assumption is problematic for various reasons not central to his theme here, but it does impinge on it. If the physical universe had a beginning, what sense can be made of laws existing eternally prior to there being anything for them to govern or describe? Where does eternality come from? Moreover, an "eternal laws" would imply that all the particulars of relations between particles, radiation, and fields of the physical universe (including the various arbitrary constants that, being what they are, allow for the development of galaxies, stars, planets, and even life) were not just accidents that could have settled into other values but rather had to come out as they did.

This is the important part. If only the physical laws had any effect on cosmological evolution up to the appearance of certain organizations then it is quite possible that those types of organizations might never have appeared (they are accidents of contingency). If that had been the history of our universe, then the psychophysical would have been entirely redundant. On the other hand, if the non-material laws had some influence on physical evolution, then that influence ought to be measurable, at least in principle. There is no evidence of such an effect in physics of course and Chalmers doesn't really care whether life and subsequent consciousness are pure accidents or were in some manner directed. It is the hypothesized connection between the physical and the psychophysical that gives him the "natural supervenience" of the mental on the physical his theory requires.

Perhaps an example of my own would make this clearer. Imagine physical law (eternal or otherwise)governs how hydrogen and oxygen interact to form water and produce its special properties. Now imagine that there is, in parallel with physical law, another law (call it XYZ) that is not physical and cannot be detected by any measurement. XYZ is entirely redundant to normal physics and the evolution of physical systems. But whenever liquid water is brought to a temperature of 300F, XYZ turns the water into a purple goo. Now normally there is no liquid water at 300F and so the XYZ law never has any effect on anything but it nevertheless exists along with the more conventional laws of physics that govern the properties of water. At some point in the evolution of the universe there come to be creatures who learn to put water under pressure and do bring its liquid state to a temperature of 300F. To everyone's surprise, the water turns into purple goo but it remains the case that as before XYZ remains strictly undetectable by physics. What Chalmers would say here is that purple goo does not "logically supervene" on the ordinary laws of physics because we can imagine liquid water at 300F without it becoming purple goo. But purple goo does "naturally supervene" on the laws of physics because XYZ always and automatically connects up water and purple goo whenever the physical conditions are made right.

My analogy goes only so far as purple goo is presumably a physical stuff while consciousness is not. Of course there is no non-physical XYZ that turns water into a purple goo. But Chalmers claims exactly this for the phenomenon of consciousness which is non-material (something for which he argues persuasively) and therefore demands a postulate of psychophysical laws which connect up with the physical under appropriate conditions resulting in a non-physical phenomenon. We can imagine all sorts of complex brain states and functional organizations existing, even having psychological and behavioral effects measureable by third parties, without there being any consciousness, that is any experience of what it is like to be a subject. But because psychophysical laws also exist (undetectable by physics), when and if sufficient functional organization comes along (whether in biology, computers, or even societies of persons) the psychophysical laws will be entangled (or activated or envoked) by the functional organization and map the physical organization into a subjective experience.

This is a proper "property dualism" for which Chalmers argues. It is a dualism because there is truly something different, that is not material, that emerges in the universe, and it is a "property dualism" because its dualistic (non-material) properties come not from some special antecedent source (for example God as in substance dualism) but from material physics albeit conjoined with psychophysical laws which are (a) non-physical, (b) eternal like the physical laws, and (c) the connecting link between the physical and the subjective-mental.

The well known dilemma of substance dualism is the "interaction problem" which challenges the doctrine on the grounds that there is no mechanism by which the physical can interact with the non-material mind stuff. For all his careful work in this book, Chalmers never appreciates the irony that his psychophysical laws must suffer from the very same interaction problem. He offers no mechanism by which this interaction takes place, that is, how it is that certain functional organizations of physical stuff become entangled with the non-physical psychophysical laws. In the end, therefore, while this book is a good example of philosophical exposition, it ends up being very unsatisfying as an explanation for consciousness.

Very thoroughly presented, in-depth scholarly work on the nature of consciousness. Not an easy read, so be warned; this book is tough going in parts, though the author helpfully informs the prospective reader which parts can be skipped over or skimmed, and where the meat of his argument can be found.

On the negative side, Chalmer's arguments are sometimes not fully fleshed out and a bit too speculative; there is too much of the "if so-and-so is true, then it possibly follows ..." and "I don't have enough information on such-and-such to draw a conclusion here" for a book that has obviously had so much work put into it. It seems that with only a little extra effort, Chalmers could have solidified some of his more speculative arguments.

When an argument pulls me kicking and screaming from a doctrinaire mindset, it deserves five stars! Chalmers argues carefully and meticulously for a dualist theory of consciousness, abandoning the materialist assumptions of most academicians. While it was difficult to imagine a non-materialistic, physical account of natural dualism, I now realize the strength and importance of such a theory in all discussions of mind and science in general. It’s a complex read for non-academics, but well worth the time.

A very good book. I work in the field of consciousness research, so I guess I'm biased with a lot of background knowledge, but I'd say, for experts this book is excellent. Chalmers approaches this problem like a mathematician. He doesn't cling to intuitions or cherished beliefs, he simply constructs arguments with cold-hearted rational thinking. His main point can actually be summarized quite simply: we, as a matter of fact, cannot deduce experiences from functional interactions. We can deduce output, and other functions, but not experiences. This then suggests a simple implication: experiences, unlike normal material entities, are not encompassed fully by functions (although they clearly correlate with it).
I'd say you really appreciate this as someone working in the field (more maybe than if you don't), because the problems he predicts are exactly the problems that arise. Every theory of consciousness at some points hits a brick wall. Global Workspace: highlighted information is conscious; IIT: integrated information is conscious; recurrently processed information is conscious; attended or memorized information is conscious; information generating meta information is conscious; neuronal interactions at 40Hz generate consciousness, and so on.
The problem with every theory, in the end, is that the starting point seems arbitrary and not rationally explainable. Why should 40Hz oscillations lead to experiences, but 39 Hz not? Why can information not simply be integrated unconsciously? What's so special about memory that it requires consciousness (as opposed to calculating root squares for instance)?
These problems that we run into in the practice of consciousness research highlight Chalmers's points: there is, in our understanding, an unbridgeable gap between functions and experiences. This makes the problem of consciousness considerably more intractable then nearly all other scientific problems.