ذهن آگاه: در جستجوی نظریه‌ای بنیادی

by David J. Chalmers, یاسر پوراسماعیل

«ذهنِ آگاه مساهمتی است برجسته در فهمِ ما از آگاهی. چالمرز ایده‌ای را دنبال می‌کند که نزدِ اغلبِ دیگر نویسندگانِ حوزه‌ی آگاهی مغفول مانده است، یا از این رو که آن‌قدر روشن نیندیشیده‌اند تا متوجهش شوند یا از این رو که از اذعان به آن ایده هراسیده‌اند. نوشتنِ ذهنِ آگاه کاری شجاعانه بوده، و بی‌شک چالمرز با اطمینانِ استوارش این جسارت را پیدا کرده که استدلالش را با وضوح و دقتی بی‌نقص بیان کند.» ـــ استیون پینکر

«ذهنِ آگاه فوق‌العاده جاه‌طلبانه و فوق‌العاده موفق است ــ بهترین کتاب در فلسفه‌ی ذهن طی سالیان بسیار. به‌مقابله با دیدگاهِ رایج می‌رود و دعویِ چشمگیری علیه عقیده‌ی مرسومِ مادّی‌انگارانه مطرح می‌کند. بی‌شک مادّی‌انگاران فوج‌فوج دست به کارِ نوشتنِ پاسخ‌هایشان شده‌اند؛ اما چندان نکته‌ای باقی نمانده که چالمرز از قبل بدانها نپرداخته باشد. ما که رویکردِ مادّی‌انگارانه‌ی مخالف داریم نمی‌توانیم دائماً بگوییم که او فلان چیز را نادیده گرفته و بهمان چیز را اشتباه فهمیده ــ چون این‌طور نیست. کلِ کاری که می‌توانیم بکنیم این است که با چالمرز هم‌نظر نباشیم درباره‌ی اینکه وزنِ ملاحظات به کدام طرف می‌چربد.» ـــ دیوید لوئیس

«یکی از بهترین بحث‌های موجود درباره‌ی آگاهی، هم در مقامِ متنی پیشرفته و هم در مقامِ مقدمه‌ای به این مباحث.» ـــ کالین مک‌گین

«ذهنِ آگاه: در جستجوی نظریه‌ای بنیادی» در سال ۱۹۹۶ منتشر شده است و از تأثیرگذارترین متونِ معاصر در فلسفه‌ی ذهن در سنتِ تحلیلی است. تفکیک مسئله‌ی «سختِ» آگاهی از مسائل آسان، و اقامه‌ی استدلال‌هایی (از جمله استدلال مشهور مبتنی بر زامبیِ فلسفی) بر ضد فروکاستنِ آگاهی به امور فیزیکی از ماندگارترین دستاوردهای این کتاب‌اند.

Genres: Philosophy, Psychology, Science, Nonfiction, Neuroscience, Metaphysics, Brain

526 pages, Paperback

First published January 1, 1996

About the author

David Chalmers is University Professor of Philosophy and Neural Science and codirector of the Center for Mind, Brain and Consciousness at New York University. He is the author of The Conscious Mind, The Character of Consciousness, and Constructing the World. He has given the John Locke Lectures and has been awarded the Jean Nicod Prize. He is known for formulating the “hard problem” of consciousness, which inspired Tom Stoppard’s play The Hard Problem, and for the idea of the “extended mind,” which says that the tools we use can become parts of our minds.

Reviews

[C.T. Phipps · Rating 4 out of 5]

Consciousness is the last refuge of the non-religious dualistic thinker. A person who believes reality is more than matter. As Death in Terry Pratchett's Hogfather put it, "TAKE THE UNIVERSE AND GRIND IT DOWN TO THE FINEST POWDER AND SIEVE IT THROUGH THE FINEST SIEVE AND THEN SHOW ME ONE ATOM OF JUSTICE, ONE MOLECULE OF MERCY. AND YET—Death waved a hand. AND YET YOU ACT AS IF THERE IS SOME IDEAL ORDER IN THE WORLD, AS IF THERE IS SOME...SOME RIGHTNESS IN THE UNIVERSE BY WHICH IT MAY BE JUDGED."

David Chalmers is something of a personal favorite among philosophers and scientific thinkers for pointing out while we understand the brain is related to consciousness, it actually doesn't make a damn bit of sense for explaining the how's of electrical impulses in an organic computer turn into "me." This "hard problem of consciousness" is a question which doesn't exist in all scientists' view but remains a vexing issue for many. It also has strong importance for questions regarding things like A.I. and interaction with the rest of reality around us.

This book discusses the implications of the fact we actually don't know how it works and does a semi-decent job of explaining it. I say semi-decent job because David gets himself confused and wrapped up in a lot of his metaphors as well as some of his conclusions along the way. He also is somewhat overly enamored of his panpsychism and zombies ideas.

I, personally, am a Sir Roger Penrose follower who believe the hard problem of consciousness is the fact information is traveling through our brains versus something that is generated within it. The "universe is the Cloud, brain is the hardware" idea. I tend to also take the view of higher dimensions ala supersymetry which we simply can't perceive the interactions of our reality from as they're non-physical. Chalmers, by contrast, prefers the idea that awareness is in each and every electron of the universe and while that's a natural idea it gives rise to the idea every video game Nazi I mow down is an actual living feeling person.

I also think Chalmers' metaphor of zombies is one which should be retired as we have better analogs now. The philosophical zombie is a being which simulates being a human being but is not actually capable of inner thought or reflection. The better metaphor nowadays would be the video game character. I can play a game of Dragon Age and talk to Leliana about her feelings, ambitions, hopes, and dreams but unless I'm an enormous dork--I am aware she doesn't have any of these. There's not a "Wreck it Ralph" style universe where I am in a human-AI relationship. Indeed, I'm inclined to believe A.I. are impossible now because the "inner life" Chalmers speaks of is something that comes from another layer of reality.

I think part of the irony there is we've become somewhat bogged down in science that we've forgotten thoughts have a reality of themselves. Chalmers felt the need to create the term Qualia because he felt there needed to be a word for feelings and experiences since we've gotten to the point of confusing neurons firing for the effect it generates (receives?). Plato's The Cave and the Realm of True Forms may have no literal existence (or do they) but they certainly reflect that we need a discussion of the human minds constructs on its own terms. Chalmers creates dualism where the material and thought break off from the physical and while I disagree with that, I am generally confused how it's even an argument. It's like the Weak Anthropic Principle in its obviousness where you'd think even the most die hard materialists would not argue "thought is different from matter."

Nevertheless, I have to give this book mad props for the fact it does question the elephant in the corner of consciousness. We can talk about the whys of life and the universe but consciousness is a far harder beast. I disagree with Chalmers that we're never going to crack it but whether panpsychicism, information via microtubles in the neurons, or the immortal soul--we needed to ask the question first.

8/10

[Jackie · Rating 3 out of 5]

I enjoy challenging my beliefs, especially the calcified ones. I knew before starting this book that Chalmers would challenge my philosophic materialism, and in a slightly self-punishing way I wish he would have done a better job. He is a brilliant man, and plays in a fucking panpsychic-themed band, and is one of the people I wish were in my circle of friends, but my margin notes became increasingly hostile before abandoning this book altogether.

This quote (from a recent Atlantic article wherein Steve Paulson interviews neuroscientist Christof Koch) encapsulates why I did not finish the book:


Interviewer: "There are plenty of very smart scientists and philosophers who say we will never crack the fundamental mystery of how matter turns into mental experience. For instance, the philosopher David Chalmers has talked about the "hard problem of consciousness." He says subjective experience is fundamentally different from what biology and physics can tell us. And he believes that science will never be able to bridge this divide between mind and matter. Do you disagree?

Koch: Well, if you look at the historical record of philosophers, it's pretty disastrous. This is little acknowledged. Lots of people from 150 years ago said the same thing about life: "You shall never understand what life is. It requires a special force, élan vital." It didn't turn out to be true. The laws of physics describe life. Roughly 200 years ago, famous philosophers said we'll never know what stars are made of. That was 20 years before they discovered spectroscopy, and of course they realized you can analyze the elements out of which stars are made. So I'm profoundly skeptical when philosophers tell us, once again, what we'll never know. Science has a spectacular record of understanding the universe. Yes, right now it's a hard problem. For its size, the brain is by far the most complex system in the known universe. There's no guarantee that we'll understand it. Our cognitive apparatus just might not be up to it, but in principle I don't see any reason why we should be unable to understand it. Just because some philosopher doesn't get it doesn't mean we shall never know this. It's ridiculous. But a lot of people are very happy about that message because, for various reasons, they don't really want to understand things in the way science does."

[Matt · Rating 5 out of 5]

This book can be separated into two parts: 1) A criticism of a materialistic view of consciousness and 2) David Chalmers' foundations for a fundamental theory of mind.

The first part is clear, powerful and very convincing. He is organized and thorough, answering the reader's every question. DC covers all of the major arguments against a materialistic view of consciousness, with his conclusion being that mental facts do not logically supervene on physical facts. In other words, it is logically possible for all of the physical facts to be the same while the subjective, conscious states are different (his 'zombie argument'). Thus, a reductive physical explanation is always going to fail.

DC makes repeated use of the intuitive question: How could physical facts explain the FEELING of this or the LOOK of that? DC's conclusion is to accept that there are non-physical mental facts about the world. Thus, he is a property-dualist (looking a lot like epiphenomenalism).

In the second part of the book, Chalmers goes a little crazy. Given the fact that he believes "we are pretty much in the dark" as far as a theory of mind goes, he takes a few stabs in the dark. He starts from the point of the view that although the mental does not supervene on the physical logically, it does supervene on the physical naturally. So in this world, there is a perfect correlation between physical states and mental states. He takes a functionalist line here. In response to critique of functionalism from Block and Searle, Chalmers argues tentatively for strong AI and panpsychism. Everything with a functional organization is conscious, he says!

Although I do not agree with his later theses, one cannot fault Chalmers for being creative, especially given the fact that he seems less burdened with preconceived notions and prejudices than other philosophers of mind are.

Ultimately, I think the major fault in Chalmers' theory is that he does not go far enough. He offers a convincing critique of materialism, accepts property dualism, but in order to avoid problems of interaction and other stigmas (such as a non-naturalistic worldview), he rejects substance dualism. The problems he is left with are more daunting than the problems of regular interactionism. But in the end, I loved this book!

[Liedzeit Liedzeit · Rating 3 out of 5]

For a long time I have avoided reading this book because I knew I would strongly disagree with the main theses. But it is sort of requiered reading if you are interested in consciousness. And also it is hard not to like Chalmers. For one thing he looked (until recently) more like an AC/DC roadie than a Professor of Philosophy and also he presents a huge collection of philosopher’s jokes on his home page.

And, of course, not to read a book because you will dislike the arguments is silly. So I did read it feeling bad until I came up to this: “For myself, reductive functionalism and eliminativism seem so clearly false that I find it hard to fathom how anyone could accept accept a type-A view.” (p. 167)

Type-A view is his jargon for the view that I more or less sympathize with. So if a guy who made a career out of thinking about consciousness has trouble understanding contrary views, I do not need to feel bad being unable to grasp his version of dualism.

Instead of going into a deep discussion of his arguments (which I cannot do and even If I could this would not be the place for it) I limit myself to two points.

First, what is consciousness according to Chalmers? He quotes approvingly the International Dictionary of Psychology saying that it is impossible to define it. And “we can say that a being is conscious if there is something it is like to be that being” (p. 4), alluding, of course to Nagel. “A mental state is conscious if there is something it is like to be in that mental state.”

Now, I find this a very poor substitute for a definition (although popular, Blackmore did the same, some years later.) My guess is that a bat has no clue how it is to be a bat whereas I have a pretty good idea. And that is precisely because I think that bats are not conscious and human beings are. So the disagreement starts before any arguments have been exchanged. Chalmers would say (and does say) that people who doubt that dogs and mice and bats are conscious are confusing consciousness with self-consciousness (p. 294) Mice “may not be given to introspection, but it seems entirely plausible that there is something it is like to be a mouse”. Just repeating a statement does not make it anymore plausible to me.

Of course, one can say that a lobster is conscious (even self-conscious) in so far as he eats anything edible but does not eat itself (an example of Dennett). So the lobster is able to differentiate between three things: edible, non-edible and edible, but to be avoided. He also recognizes fellow lobsters but does that mean that he has to be conscious? Living beings receive information from the outside world via sense organs and react according to instinct. What is added to our understanding of their behaviour by us assigning them a consciousness? On the other hand in the case of human beings it is very easy to explain how a consciousness will interfere with incoming data and behaviour. (Take, for example blindsight or phantom pain.)

If mice are conscious then where to stop? And indeed, according to Chalmers a thermostat should be considered conscious. (Or at least it must be admitted it has experiences.) Because “as we move along the scale from fish and slugs through simple neural networks to thermostats where should consciousness wink out?” (p. 295) Consequently, he arrives at pan-pychism although saying that he is not quite as convinced of that as he is of dualism.

What then is the argument for dualism? It is at least logically possible, says Chalmers, that there are beings who are just like us on a physical level, talk like us, behave like us but who lack consciousness. (Although they would claim to be conscious.) That means there must be something in addition to the material world that is responsible for consciousness. What is this stuff and how does it work? We do not really know. It is just like gravity. We do not really know how that works and it exists. “Like the fundamental laws of physics psychophysical laws are eternal, having existed since the beginning of time.” (p. 171). And then, of course, really everything must be conscious, because how should the psychophysical laws know on what objects to act on. Fair enough. Although I find the analogy a bit strained.

Curiously, the concept of a Zombie society was taken seriously by Julian Jaynes who claimed that there were people, namely our ancestors, who behaved like us but were not conscious. But Jaynes is not even mentioned by Chalmers and would not be taken seriously because the unconscious people of Jaynes were not exactly like us. They had different language and because of that different mentality. They had consciousness in Chalmer’s sense but no self-consciousness. Zombies for Chalmers are just a polemical weapon. Chalmers does not care at all about language. Of course not, mice do not have language. On the other hand if consciousness were dependent on language then the whole road leading to pan-psychism would end right at the beginning with human beings developing a consciousness based on language.

[Daniel Hageman · Rating 5 out of 5]

1. Conscious experience exists.
2. Conscious experience is not logically supervenient on the physical.
3. If there are phenomena that are not logically supervenient on the physical facts, then materialism is false.
4. The physical domain is causally closed.

These core premises, which Chalmers rigorously yet eloquently argues for (and responds to counterarguments against), are what gets his theory of mind off the ground. This book was an intellectual joy to read, and it's difficult for me not to be sympathetic to his lines of reasoning. Highly recommend!

[Kunal Sen · Rating 4 out of 5]

Before I go into any detailed discussion of this book, I must admit that even though I could not agree with many of the claims made by the author, I was still deeply impressed by his arguments and his willingness to accept that his conclusions could be wrong. That is the only way, at this point, we can hope to tackle the most difficult intellectual problem ever faced by humankind. Consciousness is so hard because we all believe we are conscious, and our inner perception is the only fact in the world we can be sure of, yet none of us can demonstrate to another person that we are conscious. In this book, Chalmers is entertaining a form of dualist view where there are two separate entities -- matter and mind. Still, unlike most other dualist thinkers, he is convinced that consciousness is not limited to living things but is substrate-independent. With the right organization, a machine can be conscious.

Very early in his argument, the author concluded that the phenomenal aspects of consciousness, that is, the hard problem of consciousness, are beyond material explanations. The arguments that he builds beyond that are all based on this conclusion. I was not convinced by the arguments that led to this conclusion, so the remaining 90% of the book, where he builds upon this conclusion, seemed less convincing.

He argues that a strict definition of consciousness is not essential to discuss the concept, and a graduated definition is sufficient. I agree with that position since we cannot even strictly define a "table," yet we can certainly talk about a "table" with coherence and purpose.

The author starts the book with the statement that he repeats every so often, that he takes the problem of consciousness "seriously," and he is only concerned about those who take it seriously, as opposed to those who explain it away. As the book develops, his definition of taking it "seriously" becomes synonymous with those who agree with his dualist view that there is something to our consciousness that just cannot be explained by physical and material factors. We must bring another notion of "mentality" to describe or understand it. In his view, anyone taking a non-dualist point of view is not taking the problem "seriously." This is an argument where he can always convince himself that he is winning the argument because any other view is not serious enough.

As he builds his argument, he presents all possible counterarguments, which is wonderful, but then he tries to refute all of them and conclude that his view must be correct since he has eliminated all other possibilities. The fallacy here is that his mathematics-like proof lacks the rigor of mathematics. A philosophical argument is not like a proof in mathematics simply because every statement is weakened by linguistic vagueness and semantic ambiguities. Yet, believing what he is doing is as rigorous as mathematics gives him a tone of sureness that seems somewhat misplaced.

This reminds me of a similar problem we face with the definition of "life." No matter how we try to define it, we can always find edge cases that can challenge that definition. This analogy goes deeper. There was a time, not too long ago, when a majority of thinkers and philosophers believed that there is the existence of elan vital. This life force distinguishes living things from the inanimate. We now know no such mysterious entity is required to understand life, and the living process can be completely understood in terms of the physical world. Yet, we are reencountering the same problem with consciousness. Philosophers like Chalmers refuse to entertain the possibility that, like everything else we know of, this last bastion of magic will also fall under the same hammer of materialism. We will eventually find a purely materialistic explanation and understanding of this most enigmatic phenomenon.

Of course, optimism is not logic, and there can be this one strange thing that will require something outside of the laws of physics. That is entirely possible, but unlikely, based on our history. However, I'd argue that this new entity, whatever it is, would then be part of our physics, as it would be needed to describe and fully understand the universe we live in. If this new thing follows logic, it should be part of our logical system, which we call physics.

Chalmers uses a clever thought experiment of a zombie, which is in every possible way like us, physically and psychologically, but does not have any conscious experience. The problem is in imagining that it is possible to think of a creature that is identical to me, but without any conscious experience, he is already assuming that the two are separable and that there is something outside of the physical world that is responsible for the phenomenological experience. My challenge would be that such a thing is an impossibility. That is, he is possibly trying to separate two inseparable things. Borrowing a conceptual tool he uses throughout the book, can we separate "water" from "wetness"? That is, can we imagine a world where water is not wet?

He talks about the epistemology of conscious experience and claims that since we can feel it directly, without any intermediate medium, it is intrinsically different from all other beliefs. We know that we are conscious. But why shouldn't it be so if we imagine that it is part of our mind that monitors and listens to some of our thoughts? Isn't it almost expected that a complex system such as our brain will evolve to have a mechanism to self-monitor? Such a mechanism will naturally feel directly connected to our thoughts. A lot of neuroscience research is pointing us to this possibility. A well-developed area of study deals with the Theory of Mind, which allows us to imagine that if I can think about you, then you can also think about me. We are all aware of this recursive mechanism as we imagine that I am thinking of what you are thinking of what I am thinking, round and round. We have even found neurological evidence of this mechanism. If we can do that with other minds, why wouldn't there be a mechanism similar to this that is self-reflexive? There are several candidate proto-theories of consciousness based on such ideas.

Of course, it is a hard problem because the experience is entirely subjective, and we cannot prove to someone else that we have conscious experiences. But this subjectiveness would be a direct consequence of a self-reflexive mechanism, and there is no way for a self-reflexive brain to externalize this experience. Despite the hardness, significant progress is being made, and there is no strong reason to believe that the materialistic approach will fail us just this one time.

I am not quite sure why someone like Chalmers would give up so quickly and adopt a dualist position with a painful prefix like "natural dualism" and introduce different physical entities. Of course, we should be ready to bring in new factors when everything else fails, but we are not even close to that state. For Chalmers, the main reason to do so is that he feels that conscious experience is so very different from everything else; it must need a special tool to explain. I have a different theory, however. There was a time when every problem in the world was a philosophical problem; over the years, during the last few hundred years, most questions that were once philosophical questions have been reduced to scientific ones. We do not need philosophy to understand the physical world anymore. Then it was life itself, which is now entirely understandable in terms of the physical world. Slowly the domain of philosophy is shrinking. It is still a handy tool to question and analyze our knowledge and discuss our moral positions. But when it comes to understanding the world, it has very little to offer anymore. The only area where philosophers may still have something to say is about our mind in general and our consciousness in particular. Therefore, it is not surprising that some philosophers would gravitate towards ideas that keep this last bastion away from the materialist and reductionist onslaught.

The final section of the book tries to connect the interpretation problem in Quantum Mechanics to his dualist view of the mind. Though he is not alone in seeing a quantum-mechanical link with our mind, and many other thinkers speculate such connections, I find these arguments unnecessary and, therefore, uninteresting.

[Griffin Deutsch · Rating 2 out of 5]

Full disclosure: I did not finish this book, and went into it with a clear physicalist disposition, trying to challenge my own beliefs.

For the first third of the book, Chalmers gives a rigorous exposition on notions of different forms of supervenience as well as possible world semantics. He's quite thorough and there was nothing too objectionable, until he got to p-zombies. This is where it went off the rails quick for me.

Essentially, Chalmers' whole argument for his brand of property dualism hinges on a main inference (p.232): "Conscious experience is not logically supervenient on the physical". To 'prove' this, Chalmers points to the conceivability of p-zombies, saying candidly that he is inclined to take such conceivability as something near obvious or self-evident. Not so much for me.

The problem: what does it mean to conceive of a physically identical world in which there are people without conscious experience? It seems that the answer to this, at best, is that we cannot make a clear epistemological claim on whether there is or is not conscious experience. It seems that in this situation under our current neurobiological paradigm this would just be an unknowable situation with any knowledge claim being mere conjecture. The problem being, Chalmers goes the opposite route, as it seems somewhat obvious to him that we *could* know that there is no conscious experience in a "physically identical world". But how could we say this? We'd have to assume that conscious experience is not physical in the first place, or at least does not always arise from physical stuff, which would allow us to conceive of p-zombies in the first place.

Seems like a bad assumption to make when arguing against physicalism.

[Brian Powell · Rating 3 out of 5]

Chalmers is a thoughtful practitioner well-acquainted with this field. He's by all accounts a grounded, critically-thinking person. Sadly, to paraphrase Rick James, "consciousness is one hell of a drug." It makes reasonable, well-meaning people go tragically off the rails.

Chalmers opens his salvo by claiming that consciousness "does not logically supervene on the physical world". By this he means that once one has fixed all the physical facts about the world, one must add something extra to get consciousness; that is, it is not entailed by the physical facts. There can thus be no reductive explanation of consciousness, and materialism is dead. The basis for this claim comes in the form of four arguments, one of which is the logical possibility of zombies. A zombie is an entity physically identical to a real human but entirely lacking consciousness. The logical existence of such an entity implies that consciousness cannot be logically supervenient on the physical. The trouble with this argument is that it appears badly circular: Why is it obvious that one can simply cleave consciousness from the physical in this way? It can only be done if one presupposes that it can be done.

Another argument is given the fancy name "epistemic asymmetry" but after much hand-wringing essentially amounts to the observation that facts about consciousness are subjective. This is indeed true, and presents a significant challenge to the scientific assessment of consciousness; however, falling outside the purview of science (if that's the case) is hardly grounds for concluding that consciousness is not entailed by physical facts. This is related to the fourth argument about Mary, the neuroscientist who has never seen the color red: no amount of reasoning about the physical facts of neurology will allow her to describe the conscious experience of seeing the color red. But again, this is just what it means for a phenomenon to be subjective: a crisis in scientific inquiry or explication, perhaps; but simply being subjective doesn't condemn the phenomenon to the dustbin of dualism.

It wasn't until I got to Chalmers' interesting concept of "fading qualia" that I realized what it is that Chalmers might be missing. He proposes this idea to support the concept of "functional invariance" which essentially says that the material form of the mind shouldn't affect its ability to be conscious, so, for example, a brain made out of silicon chips that function like neurons should be just as conscious as one with actual neurons. He argues that if this weren't true, then by starting with a brain made of real neurons and slowly replacing these neurons one-by-one with silicon neurons, eventually consciousness would need to "wink out" as the silicon brain became fully formed. Chalmers claims the only reasonable way for this to happen is for the consciousness (the qualia) the fade gradually, since an abrupt shutting off of consciousness is "almost certainly" a crazy idea. And this is where I wonder: is Chalmers acquainted with the concept of emergence in complex systems? There are several emergent phenomena that arise spontaneously from complex systems at critical moments: water freezing and self-organized firewalls in forests quickly come to mind. So why not consciousness? This might be wrong, but Chalmers seems to miss this possibility entirely.

The idea that consciousness arises from the vast complexity of interconnected information processors seems like a very reasonable hypothesis, and it's not even given a breath in this book. Without this explanation, indeed the pickings are slim and philosophers are forced into proposing things like a suite "psycho-physical" laws that sit next to fundamental physics to explain consciousness, as Chalmers does. Strange, as-yet inconceived ideas that bridge the physical and mental, are still wholly physical, yet still non-reductive. There's not much room, if at any at all, to maneuver.

Chalmers doesn't succeed in advancing a theory of consciousness based on psycho-physical laws, which is understandable given the challenge. Most of this text is fleshing out what this kind of theory would look like. Often, he aspires to future empirical confirmation of predictions of this theory that would put it on more solid footing, but, alas, we know that consciousness simply cannot be tested in this way because of Mary and her annoying subjective experiences.

Overall this book was a slog: not especially difficult but not particularly engaging. Chalmers has an almost clinical writing style, and there are *lots* of extraneous offshoots from the main development that incline you to occasionally lose site of the big picture. And, the dude, at least momentarily, considers the possibility that rocks are conscious. Which is either the most intellectually brave and honest thing I've ever read, or it's a sure sign that Chalmers is irredeemably off the rails.

[Cesar Gil · Rating 2 out of 5]

I didn't like this book. He treats conscience with a very formatted, Boolean, Cartesian thinking where everything is either true or not. With hundreds of rationalities of the either/or type. But cognition is not like that. It is a biological, chaotic process. It has no commitment to the precise boxes we try to fit it in. That doesn't mean it doesn't have a process, but we should look for something more organic.

It's also hard to understand what he proposes. He says in several different places what his theory is not, then doesn't care to clarify just as much what his theory is.

He employs throughout the book a method of proposing several different scenarios and arguments, then evaluating the validity of each one. For a start, he says that 'such and such' is logically plausible, even if not viable in practice. In other cases, he says that another scenario is not logically plausible. It seems kind of arbitrary to me. The only thing that is not logically possible is a contradiction in propositional logic. With such broad scenarios, it's hard to see how he can pin it down.

Where these scenarios are proposed, it's not detailed how it might be possible to connect the proposed components. Or even the definitions of the concepts proposed in the scenario are lacking.

Within such discussion of scenarios it's hard at times to understand what he's for or against.

At times he rejects some hypotheses as "possible, but unlikely" as if it ruled it out.

It seems to me that he was guiding the reasoning in the direction which he had already chosen.

[Christopher · Rating 4 out of 5]

Lets be clear here. David Chalmers offers the view of "Property Dualism", which rejects strict materialism with the idea that though consciousness is produced by the brain, it is not strictly reducible to the brain. This is informed by the idea that materialist theories of consciousness and neuroscience are "leaving something out" when it comes to consciousness, and I must say that the more philosophy of mind I read, the more I'm convinced this is the case.

Now, I'd also like to make it clear that I think Chalmers has proposed a theory of mind that has at least as many problems with it as any other theory. However, I think he has made a persuasive argument, that in terms of addressing consciousness, the current paradigm is failing us. That means that there has to be a new paradigm that explains the "hard problem" of consciousness, in a materialist vein, or as Chalmers suggests a dualist vein, or something else entirely.

Some philosophers, such as Richard Rorty, have suggested there is no real problem and people like Chalmers are confused by language. He suggests a thought experiment where an alien race instead of saying they feel pain says "My c-fibers are being stimulated." Rorty even gives up the game when he says that if an alien was to say that he feels the sensation of his c-fibers being stimulated but they were not he would say, "Well, it certainly feels like my c-fibers are being stimulated." What Rorty has done, and what Daniel Dennett to a lesser extent does, is deny that subjective experiences are in fact real.

This is where the conflict lies. People like Chalmers insist that they will not give up their subjective experience in order to make materialist theories work. Materialists refuse to give up the scientific assumption of materialism than give up subjective experience instead. I'm going to be honest, materialism seems a lot easier to give up on than the fact that when I feel pain, see colors or experience emotions, there is something more going on subjectively than can be accounted for by the objective physical facts. I used to be convinced by David Lewis and his functionalist account, and his response to Frank Jackson about the Mary's Room thought experiment, but I now realize something is missing from this account as well and I was biased due to my ideas of what is properly scientific, that being that materialism must be held onto at all costs.

Most of the reviews I have read on Goodreads, especially the extremely negative ones, seem to have been written by people who did not finish the book. Because of this, the reviews have two common straw men.

The first straw man is that Chalmers is saying science cannot solve the problem of consciousness. This is not true. In fact, I believe if it can be solved only science can, and certainly not philosophy. Chalmers states that he thinks science can solve it in the introduction, he merely thinks science is currently on the wrong track. Many of these people might have skipped the introduction, I skip introductions to fictional works but never nonfiction works, but a lot of people just skip introductions in general. However, Chalmers addresses this point in great detail more than halfway through the book. I actually disagree with Chalmers a lot on his basic assumptions about science in this book, but we agree that it is a problem that could only be potentially solved by science. The irony is, the more of a realist you are about science then the stronger Chalmers argument about the lack of logical supervenience of the physical facts on phenomenal consciousness becomes. This is why the tactic is to assume there is no problem or that it has already been solved.

The second straw man is to misrepresent Chalmers zombie argument. I actually think the zombie argument is unnecessarily confusing. Lets try a different thought experiment. A brilliant scientist creates an android, lets call him Data. This scientist then dies before Data is activated. Data awakens with a psychological and functionally equivalent system to human consciousness but lacks the phenomenal consciousness of humans, including emotions. He travels to earth, and has a full physical knowledge about all the facts of human beings. However, when humans try to explain the phenomenal experience of their consciousness he doesn't believe this exists, because it cannot be logically obtained from the physical facts. This is all the zombie thought experiment states just framed differently, that the physical facts do not supervene on the phenomenal state of consciousness. Data is "functionally" human but is missing something to make him truly and fully human, but because he cannot obtain what his is from physical facts he thinks it does not exist.

Chalmers does a good job of addressing every objection a person might have of his view. He doesn't refute all of them but he does address them. Critics of his view could at least be equally as diligent. There are some structural issues I have with this book, mainly that the way things are divided up in the book contributes to boring the reader because they aren't sure what Chalmers is getting at until fifty pages later, and answers to certain objections should be closer to where the idea was originally proposed in the first place. That said, it is a solid and challenging entry on this subject.

[Jana Light · Rating 3 out of 5]

I go back and forth on this one. I'll need to take a bit to let what I really think about the work bubble to the surface. Review to come.

[Veronica · Rating 5 out of 5]

For a complete laywoman in philosophy and consciousness, this was an enjoyable, interesting read that I could also comprehend.

[Chris Naylor · Rating 1 out of 5]

An interesting but unconvincing read. I agree with Chalmers that we do have consciousness, and that reductive theories don't work. However, I have several problems with Chalmers' own theory:

1) Given that, on Chalmers' theory, phenomenal experiences are not causally explanatory, how do we account for the extremely close "fit" between phenomenal experiences and their physical counterparts? For example, why when I burn my finger do I feel a pain in my finger, rather than a pain somewhere else or an entirely different sensation, e.g. the smell of onions? Chalmers thinks this is because of the psychophysical laws that obtain in our world, but all this does is push the problem back a step, because there must be many logically possible worlds whose psychophysical laws mean that this close fit is absent, and given the vast number of possible alternative phenomenal experiences that could, under logical possibility, accompany my burning my finger, it seems remarkably coincidental that I happen to live in one of the small minority of worlds in which the psychophysical laws result in an almost ubiquitous close fit of this kind. Chalmers does not raise this problem, and I assume has not noticed it. (Note that here I am supposing, as Chalmers does, that logical possibility is a reliable guide to actual possibility in some actual world. As I explain further on, I think this is a mistake, but for the moment I am accepting this idea simply in order to point out a flaw in his reasoning.)

2) How do I know I am not a zombie? I do seem to know this, yet on Chalmers' theory I don't see how I can know it. Chalmers says that I do know it, because I have direct experience of my own consciousness, and therefore my belief that I am not a zombie is justified, whereas the zombie's belief is not. But that is also exactly what the zombie thinks about himself. My belief that I have direct experience of my own consciousness is created by a physical process in my brain, which the zombie also has, and so the zombie, like me, also believes that he has direct experience of his own consciousness. How can I check that my belief is correct, and that I am not a zombie making a mistake? It is no good my introspecting, checking my consciousness to see whether it is actually there, because whatever it is that occurs in my brain to cause my introspecting and checking that I am conscious also occurs in the zombie's brain, so that the zombie also believes that he is introspecting and finding that he is conscious. And even if I find that I am conscious, this is something that goes on entirely within my consciousness, and according to Chalmers' theory, nothing that happens in my consciousness can change a belief that is created by physical processes in my brain, because the world, according to Chalmers, is causally closed, and even if phenomenal events can be causal, they cannot be causally explanatory, which they would need to be in order to change something that has been caused by my brain. So Chalmers' theory, despite what Chalmers himself says, entails that I cannot know that I am not a zombie. And yet I do seem to know this. (This is really a new version of an old problem with materialism: if my thinking is entirely caused by physical processes in the brain, what reason do I have to trust my own thinking?)

3) I am unconvinced by Chalmers' view that conceivability entails logical possibility. At one point he says this:

For example, one might think that one can conceive of a situation in which Fermat's last theorem is false, by imagining a situation in which leading mathematicians declare that they have found a counterexample. But given that the theorem is actually true, this situation is being misdescribed. It is really a scenario in which Fermat's last theorem is true, and in which some mathematicians make a mistake.

Chalmers wants to prove that conceivability entails logical possibility in order to bolster his belief in zombies. I agree that we can conceive of zombies, but not that this shows they are logically possible. I think Chalmers is making a mistake.

Firstly, he is conflating conceiving with believing. We make no mistake when we conceive of something that is not the case, only when we believe it to be the case.

Secondly, "x is logically possible", if true, is a fact about x, whereas "Chalmers conceives of x" is a fact about Chalmers. "x is logically possible" is a fact about the world outside Chalmers himself, whereas "Chalmers conceives of x" is a fact about what is going on inside Chalmers. The second kind of fact cannot by itself entail the first kind of fact; they are unrelated.

Thirdly, he is attacking a straw man. When I conceive of Fermat's theorem being false, I do not conceive of methematicians saying it is false, I conceive of discovering, somewhere among the vastness of the realms of number, a counter-example to Fermat. We cannot dismiss this conception by saying that I am making a mistake; I would only be making a mistake if I believed that there actually is such a counter-example. Merely conceiving that there is is not an activity in which I can be mistaken.

I think Chalmers is working with an incorrect model of conceivability. To conceive of something is merely to have the concept of that thing. If I conceive of Fermat's last theorem being false, all I am doing is entertaining a concept. It is not a very detailed concept - I cannot flesh it out with e.g. two cubes that add up to a third cube - but it is still a concept. As such it is not connected to what may or may not be possible in the real world. That is a separate issue.

Drawing on a suggestion made by the philosopher Nicholas Griffin in his paper "Rethinking Item Theory", published in Russell vs. Meinong: The Legacy of "On Denoting", I would suggest that conceiving, or conceptualising, always occurs, not in the real world, but in what Griffin calls "contexts of supposition". (I think my model here is slightly different from Griffin's own, in that he reserves contexts of supposition for things that do not exist in the real world, whereas I suggest that these contexts come into play in all instances of conceiving. I hope I am representing Griffin correctly here - it is a while since I read his paper, and I do not have it to hand.) Impossible things can exist in these contexts of supposition - which is to say no more than that we are supposing them to exist in order to think about them. Some of these contexts of supposition align with the real world, and some do not. Thus if I conceive of Fermat's last theorem being false, I am doing so within a context of supposition in which the theorem is false; this context does not align with the real world, because in the real world the theorem is true. Conversely, if I conceive of the theorem being true, I am conceiving of it within a context of supposition in which it is true, and this context of supposition does align with the real world.

Quite often we may conceive of something in a context of supposition without knowing whether this context aligns with the real world. This was the case with most mathematicians before Andrew Wiles proved that Fermat's last theorem was true (although Fermat himself, who claimed to have a proof of his theorem, may have been an exception). Then, as now, mathematicians (and indeed all of us) were able to conceive both of Fermat's last theorem being true in a context of supposition in which it is true, and of its being false in a context of supposition in which it is false, without knowing which of these contexts of supposition aligned with the real world (again, Fermat may have been an exception). Since Andrew Wiles proved the theorem true, we now know which context aligns with the real world. This does not affect the conceiving, which can go on exactly as before.

In the case of zombies, I think Chalmers is conceiving of them in a context of supposition in which there can be zombies, while philosophers who do not believe in zombies, such as Dennett, are conceiving of them in a context of supposition in which there can't. Which context aligns with the real world (in other words, who is right)? The only way to find that out is to find out whether zombies are possible in the real world. We cannot short-cut the process by appealing to conceivability - or such is my opinion.

How would we find out whether zombies are possible? By empirical research. We find out what is empirically possible by finding out what is empirically actual and then extrapolating from it. This is the only way to solve the hard problem (if it is to be solved at all). It cannot be solved by appealing to the notion of logical possibility, because to say that X is logically possible is merely to say that in our description of X we are not infringing some law of logic. Laws of logic are therefore concerned with language, not with empirical reality and empirical possibility. Chalmers is using the wrong tools for the job. This leads him to say silly things about research. At one point he actually says that an experiment is not worth doing because we already know what the result would be! No. A real experiment is worth a thousand thought experiments. We find out how the world works by practical experiment, not by armchair thinking.

4) Another view of Chalmers' that I cannot agree with is that anything organised like a human brain would be conscious, irrespective of its physical constitution. This again is an empirical question. The only way to find out if a machine can be conscious is to build one and see if it is. In practice this is impossible, because if we did build one and it told us it was conscious, we would have no way of knowing whether it was telling the truth. The correct answer to the question "can a machine be conscious?" is "I'm not a machine, so I don't know."

5) On the question of the correct solution to the so-called 'hard problem', I am uneasy about Chalmers' property dualist position. It seems to me that the plausibility of any kind of dualism decreases in direct proportion to its ability to resolve the supposed hard problem. In the case of property dualism, we are apparently supposed to accept that the brain is partly physical and partly mental. This would no doubt explain how a physical object can have mental experiences, but does the idea of a half-physical, half-mental object make sense? What, indeed, is it for an object to have mental properties? What form of existence does the mental have? In what medium does it exist? I see no way of grappling with and answering these questions, and I am left with the feeling that the mental is only postulated at all because we find it surprising that brains can be conscious. Surprise is not a reason to expect further explanations. Relativity and quantum theory are both surprising, but that doesn't give us good reason to think that underlying both are facts that we would find less surprising than they are.

In conclusion, consciousness is certainly puzzling, but I see nothing in Chalmers' book that helps to reduce the puzzlement.

[Zarathustra Goertzel · Rating 2 out of 5]

The Conscious Mind is difficult to review.

Wikipedia cites Chalmers as maintaining that the book is "far from perfect" as it was mostly written as part of his PhD dissertation. Thus despite the work's broad influence, harsh critique would be undue and unfair.

Moreover, examining https://plato.stanford.edu/entries/co..., it appears that Chalmers played an important role in shifting to clearly articulating a Neural Correlates of Consciousness itself and that people spoke rather unclearly in these regards beforehand. In deference to this, the book receives two stars 😊. Kudos to Ben Goertzel for pointing this out in numerous discussions inspired by reading the book.

Frankly, I lean toward "taking consciousness seriously" and recognizing that theories of reality are inferentially explored from inner/outer sense-data. So I was expecting to largely agree with Chalmers (based on what I'd heard about what people took from his work). I am utterly shocked at how disagreeable someone's rhetorical style can be even where I wish to grant him the benefit of the doubt and sort-of-agree in the big picture. Imagine we agree on postulate C and yet he proceeds to offer 5 unsound arguments for C in extreme confidence (with an air of derision for anyone who doesn't agree with at least one of these); he admits there's some intuitive element to some of them (such as the infamous p-zombie thought experiment) yet nonetheless refers to them as if they're sound and conclusive reasoning. I want to try to write a generous review or lean toward steelmanning, though I may not succeed. "Chalmers is not even wrong" might do a lot of tCM justice.

"Steelmanning is the act of taking a view, or opinion, or argument and constructing the strongest possible version of it. It is the opposite of strawmanning."

I saw the claim recently that, "being easy to argue with is a virtue". In terms of popularizing terms and nudging the general philosophical and scientific community, this may be the case. Flame wars and trolls certainly exemplify this -- as frustrating as they can be, trolls may provoke greater debate and inquiry into a topic than polite, humble people would. (And as with negative-reinforcement based learning, this could introduce knotty conflicts into the space of dialectic that seem to hold one back.) Thus being contentious, unclear, self-inconsistent, etc., may all be features, not bugs in the bigger picture beyond the pages. I would have discussed the book far less if it were more palatable, to be honest.

Also, to be fair, I have not read that much analytical philosophy. I am more familiar with the cultures of formal logic and general AI.

The introduction of terms, psychological vs phenomenal consciousness, etc., was pretty decent.

Chalmers heavily uses the concept of supervenience, which I find to be a bit suspicious and confusing. Historically, the term seems to have originated for use in meta-ethics and emergentism in the 20th century.

David goes with the following sort of definition (which I paraphrased from the Stanford Encyclopedia of Philosophy): "A-properties supervene on B-properties if and only if there cannot be a difference with respect A properties without a difference in B properties". The Wikipedia page gives multiple definitions, one of which is, "for all x and y, if x and y are indiscernible for all B properties, then x and y are indiscernible for all A properties".

To me, this looks like what I think of as an injective or one-to-one mapping between B and A, stated backward, which, imo, adds confusion. The idea seems to be to make abstract arguments about dependence relations that one believes hold without knowing 'how'. For example, the notion of "the beneficial effect of an act of charity" might depend on the state of the agent and the world but we don't know the precise theory. Additionally, what if two domains can be in a dependence relation without there being any concrete manifestation of this correspondence? If so, then perhaps the "supervenience framework" might help. I don't like this framework and suspect it can probably lead to more confusion than it helps (so I'll aim to use other terms instead).

The aim is to investigate whether "phenomenality supervenes on physicality" (where I use -ity as shorthand for "-al properties"). Is there some hypothetical mapping from physical truths to phenomenal truths? Such that, given a physical description of a (subset of a) universe, one can determine a phenomenal view of this universe ('s subset).

David holds that the answer is "yes" (which seems to be the standard, mainstream attitude in 2022 -- well, barring the fact that the majority of humans on Earth are religious 😋). However, this correspondence is an empirical fact and does not logically follow from physical theories themselves. Thus Chalmers argues for "natural" rather than "logical" correspondence.

Apparently, it seems commonly held that physicality 'obviously' doesn't 'supervene' on phenomenality (e.g., from SEP, washing machines and ski masks differ physically yet are the same phenomenally in lacking mental properties). Panpsychism or any stance holding that phenomenality is ubiquitous would render this 'uncontroversial' example erroneous. Moreover, it's not clear to me that this is a helpful interpretation of a mapping from phenomenal truths to physical truths.

A common, cliché, argument going back millennia posits that physical truths are inferred from within "a sea of conscious experience", i.e., from phenomenal truths. Measurement apparatuses are built extending the reach of our observable phenomenal truths. Given that any known physical difference is known by its reaching our "manifest image" of phenomenality, the only way that this 'supervenience' relation could be violated is by our physical theory (used for determining what is physically true) suggesting the existence of distinct entities whose difference we can not measure. Should such a non-measurable physical distinction count as a physical property? If not, then it would seem there's a simple argument that physical properties depend on phenomenal properties.

Given that this argument is very simple and age-old, I was very surprised to find near zero mention of it in the whole book.

I suppose this would be "epistemic supervenience": the arrow is from knowledge of phenomenal properties to knowledge of physical properties.

Whereas "logical supervenience" deals with possible world semantics: is it the case that in all possible worlds where B holds, A also holds. Thus the question is actually one for our theories of reality and not of our knowledge. (Ironically, in Constructing the World, Chalmers argues that analyses based on warrants and proofs for justification are probably a more sound approach. I tend to agree. The modal analyses in terms of possible worlds seem an easy way to noodle oneself into confusion.)

The crux of the argument is that our physical theories (the mathematical laws of physics) do not cover the nature of phenomenal experience, err, phenomenal truths -- what 'the delicious succulence of an apple' tastes like (rather than the physical theories explaining the dynamics of how taste works physiologically and neurologically). This is notoriously hard to articulate. Nagel seems to do better in "what is it like to be a bat?"

In A Brief History of Time, published one year later, Stephen Hawking puts it: “Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?”

I believe Russell also noted the problem that science describes how the world works but doesn't seem to tell us "what the world is made of". Some interpretations of Buddhist doctrines on emptiness are also of this nature.

Take the example of "1+1=2". The equation seems to hold of our reality. But what is the fire of the equations? Apples? One apple and one banana is two fruit? Think of the phenomenal properties of apples and bananas: the redness, the taste, the smell, etc. Does knowing the light's wavelength is 666 nanometers tell me what the redness is like? Only if I look at a color spectrum chart.

Chalmers' goal is to argue that no possible theoretical details in terms of mathematical laws can tell me what 666nm light will look like to a human. The equations do not ignite themselves. At some level, a non-reductively-explanatory correspondence will have to be made associating some physical property with some phenomenal property (which can then be extrapolated from to infer the redness of an apple for a specific human being, in principle).

I don't really disagree. I find the challenge of aligning the abstract and the concrete to be quite intriguing. To an extent, I can see how to embed the abstract in the concrete and the concrete in the abstract. Realizations of the abstract in the concrete do seem to lack some of the "timeless" nature people want to ascribe to, say, "1+1=2". Adam Pease, developer of the SUMO ontology pointed out that if one tries to reduce the abstract to the physical, then one will need to face up to statements such as, "'2' began at some point in time." Which I may embrace. Abstractions tend to leave off some details of the concrete (-- this is a feature, not a bud --). But does this mean that abstractions, as physical theories are, will never quite fully specify exactly "what the universe is"? Perhaps. I'm not sure.

This brings us to questions such as, "Why does anything exist at all?". Sure, we know a lot about how the universe works but why does the universe exist? Why is there experience? Why isn't there just a flux of abstract laws sans qualitative content? Why isn't there simply nothing at all?

(Andrés Gómez Emilsson has a fairly fun video on this topic: Why Does Anything Exist? Zero Ontology, Physical Information, and Pure Awareness https://www.youtube.com/watch?v=KdDNf...)

This is where empiricism comes in: human knowledge comes from experiences gathered through our senses -- via phenomenal data.

Rationalists want to derive all knowledge from first principles, however. Empirically, we know that something exists (namely my First experience :D). Rationally, we really want to avoid assuming this upfront. Thus the whole point is to argue that some sorts of phenomenal properties will have to be worked with empirically.

Is a supervenience framework needed for this? Probably not. Is it needed to show that David knows the standard technology of analytic philosophy to get his PhD? Quite possibly!

How does Chalmers argue for this? In various ways, almost none of which I find satisfying (despite holding that there are many elegantly simple ways to make the core point). One is via a thought experiment under the assumption that "conceivability entails logical possibility", which he concedes ultimately rests on his intuition (and is thus an unsound argument). (The infamous p-zombie scenario.) He appeals to Mary's Room as well, which I also judge to be distracting and uncompelling. And appeals to analysis don't amount to much more than arguments by assertion: "physical theories just don't explain the sweetness of tender kisses!"

Chalmers seems to enter a sort of "high school debate" mode of high-confidence assertions as if the point is "to win" by convincing the reader that he has "adequately argued for his claims". This seems to take precedence over clearly fleshing out actual content. Moreover, there are caveats such as recognizing an argument rests on his intuition (which may not be shared by the reader) and then he later refers to the assertions as if they have been proven beyond any reasonable doubt. This leads to the text lacking in self-referential integrity (and is why I'd advocate basic academic humility in not claiming to do more than one does, or at least appearing to try not to 😋).

Chalmers concludes that one is left with a sort of "naturalistic property dualism", namely that there is one ontologically fundamental substance with two types of properties: physical and phenomenal.

He notes that (cosmic) idealism and panpsychism might also be valid, yet sets them aside. Let alone generic neutral monisms other than strawman materialism. (And God forbid letting go of substance-based ontological bases!)

Much of the book reads like attempts at building up towers of logical inferences as if the conclusions are all that matter (rather than clear expositions of the content) where there are sufficiently many weak links that the tower doesn't quite stabilize. If one is not convinced of every earlier claim, then the later claims sort of fall through.

Part III is perhaps the most fun where Chalmers explores principles for a theory of consciousness (yay, content). This mainly focuses on principles of coherence, which is like the identity theories of consciousness that argue for and postulate a one-to-one correspondence between physical and phenomenal properties that goes in both directions. Like a two-way supervenience. This is pretty much "standard functionalism" (though apparently this was less coherently elaborated on back in the day).

Frankly, given that I'm not convinced his notion of "logical supervenience" is particularly meaningful (beyond the standard observation that abstract theories don't seem to tell us what it's like when they're realized in a phenomenal system), I am almost dumbstruck when after a whole book of raving about how it must necessarily be impossible for there to be a "logically necessary" relation of this sort between phenomenality and physicality, he then goes all-in on arguing for a "natural isomorphism" between them as if it's almost logically incoherent (especially given our evidence) for this to not be the case. Maybe there are possible worlds where they are not linked as they are in our world, but in our actual world, they seem to be tightly coupled! :'D

(Thus the main thesis of the book is actually about how to theorize for as far as our actual world is concerned, physicality <-> phenomenality.)

There are some fun explorations on the nature of phenomenal judgments, like, how is it that we can make judgments about phenomenal experience (which do seem studyable with standard physicalitst approaches)?

The speculative section on information theory as a possible means to unify phenomenality and physicality is fairly interesting (and more humbly written).

Finally, he argues that strong AI with phenomenality is most likely possible.

One quip with talking about "the principle of organizational invariance", speculating that functionally equivalent systems will experience the same phenomena, is that it's not so clear to me where to draw the lines of "functional significance". Is it at the neuronal level and "atoms of experience" will be associated with individual neurons? Or are all cells relevant, including the microbiota in our bodies?

The topic of coarse-graining (term thanks to Lee Smolin) seems important here. When can we choose an appropriate level of abstraction at which to analyze organizational invariance? I lean toward stances in which phenomenality is ubiquitous, which would make ruling out any fine-grained levels of physicality from questions of phenomenality difficult.

Fortunately, we'll eventually be able to experiment with neural implants, augmenting our brains or perhaps serving some "analogic" functional roles. Second person science will also be quite interesting.

. . . and, sure, physically similar configurations such as Zar now and Zar at t-10 seem to enjoy phenomenally similar experiences.

What does The Conscious Mind aspire to tell us about the nature of conscious experience and our ability to understand it?

Not much.

The main points seem to be:

A) that we should take phenomenal experience seriously and try to talk about qualitative experience explicitly as we concoct theories.

B) that mathematical theories will not tell us what the content described is like phenomenally, i.e., we need terms of phenomenal qualities in the languages for our physico-phenomenal theories.

While this is notoriously hard to discuss with clarity, I am not convinced The Conscious Mind helps much. Chalmers almost seems to claim that the answer to "the hard problem" of consciousness is "no" -- yet is also open to some future theory unifying theories of physical and phenomenal systems. The topics he's known for that I expected to find elucidated better than on philosophical summary pages were not expounded upon any better. If anything, I think some of the tools presented in this book might mislead and confuse one.

I recommend most people against reading this book. The work may be a historically relevant relic to be honored with deference?

If interested in the content, please seek summaries of the core theses instead of attempting to read it.

Curiously, I rather liked Chalmers' latest book, Reality+.

He seemed to be getting out of the adversarial high-school debate mode for most of Reality+ (for whatever reason). I am grateful and hope that his future philosophical works will be more constructive, interesting, and beneficial :-)

(As a note of personal reflection, I find it quite interesting that "messy books" can end up stimulating far deeper thought on an issue than "clean, compelling" books that I just read and nod along with. If the goal is to inspire thoughts in my noggin, then messy, contentious writing could actually be more effective. The Conscious Mind is very, very good practice for trying to generously read a text and distill the interesting ideas from the confusion. My capacities are close to leveling up and hopefully I will be transformed by the time I'm through Constructing the World!)

[Siyang · Rating 4 out of 5]

I learned from David book what is the hard problem of consciousness, and the necessity of philosophy of language returning to philosophy of mind. What I haven’t got from the book but really wanted to know is how to exactly computerize consciousness. As a computer science phd student, I am always seeking the answer to that problem. I didn’t gain insights however.

[JCJBergman · Rating 4 out of 5]

A good overview of the philosophical discourse and status of consciousness. However, I was expecting a bit more of a conclusive view from Chalmers.

[Elliott Bignell · Rating 3 out of 5]

The middling star-rating indicates that I was faced with a real dilemma in reviewing this book. Chalmers' conclusions towards the latter half are unobjectionable and would seem a coherent contribution to the problem of consciousness taken on their own. The problem is that the route he takes to get to them is one extended exercise in question-begging, and ultimately self-defeating. Subtly or not so subtly, Chalmers again and again builds arguments based on the assumption of what he seeks to demonstrate. It comes down to "supervenience", and the authors' assertion that subjective consciousness cannot be logically supervenient on physical facts. His arguments to this effect invariably beg exactly that question, for instance in the "arguments from conceivability" which postulate that it is "conceivable" that a zombie could exist without phenomenal consciousness while being atom-for-atom physically identical with a conscious person. Well, yes - conceivable if you can conceive that phenomenal consciousness obtains independent of the physical brain: if, in other words, you assume what Chalmers is setting out to prove.

Arguments from conceivability are always suspect, and if Chalmers has really achieved anything with this book it is to show why. Ironically, he returns to this issue later in the book and uses a series of "slippery slope" thought experiments to show that the phenomenal cannot be independent of the physical, showing that fading and dancing qualia lead to inconsistency in a way reminiscent of Douglas Hofstadter. Another argument from conceivability seems to be downright incoherent; Chalmers returns repeatedly to the idea of "inverted" qualia - what if my red is your blue or yellow? Chalmers is obviously familiar with Nagel's paper on the problem of mapping the subjective experiences of others. (Using bats, to be precise.) What he appears to have missed is that Nagel's work shows that the qualia of different individuals are in fact outright incommensurable - there is no sense in which they can be said to occupy a space in which one can be inverted vis-a-vis another.

At other junctures, Chalmers pursues Mary, who sees red for the first time and apparently gains new information. But since when did the new information in a new relationship between subject and object require a radical new theory? It seems obvious, blindingly obvious if one wants to be facetious, that the phenomenal "facts" of consciousness arise out of the mapping between the perceiver and the perceived, and someone who sees red for the first time has established a new link in the mapping. I am almost staggered that a philosopher could have missed this. In the end, Chalmers effectively concedes defeat, saying that qualia "just" arise as a fundamental law of his naturalistic dualism in exactly the same way that we could have said all along that they "just" arise out of computational self-reference or introspection. I wanted to shout in rage and frustration at this point.

I have been harsh, and could based on my notes have droned on in this vein for longer than the book itself, but I have to say that the latter half tends to make up for it. The blurb suggests rather ridiculously that Chalmers has been courageous in publishing a book that criticises materialism, when evolution-denial and what-the-bleepism in fact suggest that the culture is straining at the bit for ways to shove dualism back onto the agenda. However, Chalmers rejects a "materialistic" and reductive model of consciousness only to promote a naturalistic one based in brain organisation and information theory. And this I can wholeheartedly endorse, while wondering if it was worth the effort of doing it this way. As far as the political environment outside of neuroscience is concerned, naturalistic is presumably no gain over materialistic, so one has to wonder at the fuss!

At any rate, Chalmers writes clearly and establishes his terms in a way that one can follow. For this he deserves praise, even if some of his foundations seem to rest on simple fallacies. And I am sure that his conclusions are close to the mark - at some stage we will start to be able to repair the brain with prostheses, and we are already seeing odd translations of the sense of self in telepresence technology. Somewhere down there, the self arises out of what is going on in the brain, and can arise if the same thing goes on in something else. Thus far, I have to agree.

[Bob Woodley · Rating 4 out of 5]

Finally getting around to this influential book by David Chalmers. Interesting tidbit: Chalmers received his PhD in philosophy and cognitive science from Indiana University Bloomington under Douglas Hofstadter.

Chapter 1 is an exciting start to the box and could stand alone as an essay. It contains many of the ideas that will be developed later at greater length and introduces many of the concepts he has become famous for: e.g. "The hard problem of consciousness" and "Philosophical Zombies".

Chapter 2 pivots to hard-core (for me) analytical philosophy and gets into concepts like supervenience. I didn't understand it all and am still particularly confused by "intension".

In Chapters 3 and 4 he develops his dualist theory of consciousness. Chapter 4 deals with one of the more pernicious implications of his theory: it robs us of free will due to the inability of consciousness to impact causality. (That's my simplified understanding; his view is much more nuanced).

Chapter 5 deals with whether judgements about conscious are physical or phenomenlogical. This begins to feel a bit like "how many angels can dance on the head of a pin" and I feel like he is drawing too many conclusions from his philosophical zombie example.

Chapter 6 is where he starts to pull together his own theory of consciousness. He postulates a set of phenomeno-physical laws, laws that will explain consciousness via direct reports. For example, if you look at something and a brain scan reveals a certain neurological pattern and then I ask you what you are experiencing, then your report thereof will allow us to establish links between the physical and the phenomenological. This approach has so many logical inconsistencies I wouldn't even know where to start BUT he makes some really interesting observations along the way. For instance, do consciousness and awareness always go together? It seems that way, though a special case would need to be made for dreams and hallucinations.

In Chapter 7 he sketches out a theory for how consciousness must arise from functional organization. So given the right functional organization even silicon would be conscious. I found something to disagree with in almost every paragraph. It seems to be all pure speculation backed by specious scholastic arguments.

Chapter 8 is about information spaces. Apparently some philosophers and physicists postulate that physical reality is nothing but information spaces. Chalmers then speculates about what the resultant physical/phenomenological interactions might look like. This is where he famously speculates about whether a thermostat could be conscious. (Daniel Dennett has a hilarious, and unfair, send-up of this in "The unimagined preposterousness of zombies"). Chalmer's ruminations veer towards panpsychism but gets stuck at the Combination Problem, though he doesn't use that name.

Chapter 9 questions whether AIs could ever be conscious. This book was written in the 90s, so I'd be interested in hearing an update on his views. His view is 'yes' they can be conscious, but the argument is highly technical and unconvincing.

Chapter 10 speculates on the implications of Quantum mechanics and the collapse of the wave function for any theory of consciousness. The chapter is a useful survey of the philosophical problems with each of the proposed theories for this paradox. All of them have major problems. Even Chalmers admits his own proposal is hard to take seriously.

I don't know why I find this book so enjoyable, because at the end of the day I don't believe in his project. I find Advaita Vedanta the most coherent explanation of consciousness (and much else). Reading Chalmers (and many analytical philosophers) is like baby steps compared to Vedanta. There are so many assumptions and blind spots.

But still, it is also a pleasure to read an logical exposition by an intelligent mind.

Philip Goff's book "Galileo's Error" contains a good short overview of Chalmers' book if you don't want to wade through this tome. But then you'd be missing engaging with such a thoughtful person.

[Ricardo Acuña · Rating 4 out of 5]

Consciousness is still not completely understood, and many of the great minds in the history have tried to search for a theory to completely explain it but it remains difficult to achieve, up to now. David J. Chalmers makes a remarkable try in this book that is worth to read it.

Chalmers recognize that the problem of consciousness lies uneasily at the border of science and philosophy, and is extraordinary difficult, if not impossible, to study using the scientific methods. This is a key fact that permeates the rest of the book. Chalmers recognize that the problem of consciousness may be a scientific problem but uses philosophical methods to understand it. For me, neither of both is completely true, and can not be asserted. As matter of fact, no one really knows if consciousness is something to be studied using scientific methods or philosophical methods, or even, some still-unknown method.

The first chapters (1-4) use philosophical methods to explain Consciousness, explaining “supervenience” as key concept to define the relationship of mental states with the physical states. It was extraordinary difficult for me to read it and follow it (I´m not a philosopher), so I just skim through most of it (as suggested by Chalmers). A large part of this section is devoted to defining what is consciousness, the conscious experience, the cognitive process, functionalism, physical vs psychical states, and so on. But no final definition of consciousness is fully achieved. Also, the mind-body argument is strongly argued against many of the arguments of other authors (Rosenthal, Dennett among others).

Then Chalmers analyze the consciousness problem using a cognitive psychology model and process approach but without really going anywhere. Then interestingly Chalmers switches to quantum mechanics theory as a possible explanation of consciousness being the “observer” entity required for quantum mechanics to work. Then later Chalmers discuss the Information Theory, as another alternative explanation of consciousness which inadvertently bring us to a “panpsychism” realm.

This book at heart is really about an epistemic problem. For me this is an important corollary. As Chalmers himself admits: “Given the actual epistemological assumptions. We need to find a new paradigm”. I completely agree with this statement. Chalmers proposes a final theory, as a set of psychophysical laws analogous to fundamental laws in physics, but do not go into the details or the foundations of it. At the end Chalmers seems to agree with the Everett interpretation of quantum mechanics: “the Everett interpretation seems in many ways the most attractive, but at the same time it is the hardest to accept.”.

There is a lot to say about this book, but it is not my purpose and I´m not able to do a comprehensive review. This book is very technical, I´m not a philosopher, but although it takes me more time than usual to read it, it was worthwhile. I really like to read and know about the consciousness problem, and this book give me valuable answers: Consciousness is out of the scope of science method and philosophy, and we need a new epistemic approach; This book is an evocative journey to understand consciousness from quite different views, perspectives, models, methods, and though not conclusive, it is worthwhile.

[Joshua Nomen-Mutatio]

I just returned it to the library. Someday I will finish it. I'm just currently and strongly persuaded by the physicalist and eliminativist end of the spectrum so much so that I simply lost interest. I know of Chalmers reputation as having made great contributions to the subject of consciousness. I think where I most differ with property dualism (anomalous monism being the most persuasive version for me so far) is with regards to the problematic notion of epiphenomenal mental states (which Chalmers admits is a rather large problem for property dualism, functionalist or not) and the overall attitude towards the ability for neurophenomenology and other collaborations between neuroscience, philosophy, cognitive and/or experimental psychology and other fields in developing better understanding of consciousness. I think that pessimism on this front is pretty much unjustified or at best not up to date on what's taking place research wise. Basically, I think that the mapping of the neural correlates of consciousness and analyzing the data through multiple collaborating fields and then forming theories which may bear out new data which form more theories or refine old ones and continue onward hopefully illuminating new things and giving useful and interesting insights.

More later...

[Puja Killa · Rating 3 out of 5]

2.5*
A mixed bag. Some parts were very insightful. But for the most part verbose and repetitive. And after all the rambling using serious sounding philosophical jargon, the conclusion was that we will likely never understand consciousness and that even a thermostat could be conscious. I disagree on both points.

On the plus side, I liked his turn of phrase and enjoyed reading non-technical bits. The only reason I didn’t mind the technical parts was because I didn’t read them. I also learnt that Philosophy is something I should stay clear of.

[Andrew Noselli · Rating 3 out of 5]

This book is concerned with the history of psychobiological development as it pertains to the philosophy of science behind the evolution of consciousness in homo sapiens. While giving several options for his conclusion, as befits a man of his great critical acumen, Chalmers appears to leave it up to his reader, the budding philosopher who willingly follows him down through the pages of the book, as to whether moral experiences are as problematic for conscious experiences as scientific problems; but only in the sense that both fail to supervene logically. This refers to the philosophical debate about whether our understanding of the nature of morality poses a significant challenge to our comprehension of consciousness as the scientific quest to explain how physical processes give rise to subjective experience, which is essentially asking if explaining what it feel like to be moral is as difficult as explaining what it feels like to experience anything at all. Moreover, just as there seems to be a gap between the physical world and our conscious experience of it, which renders it difficult to explain how consciousness arises from purely physical processes, there is also a similar gap between the physical world and our moral experiences, which makes it difficult to derive moral values solely from physical fact, which are distinguished by the fact that they don't seem to follow logically from the physical world alone. Initially, my thought was that perhaps this philosophy is relevant for the politics of Trump's zero-sum world, where you can no longer achieve a credible victory with a straightforward application of the rules of the game.

Despite the scientific weightiness of his discourse, I see that Chalmers leaves open the possibility that a supernormal being like God took care of microphysical reality by imposing a set of high-level intentionality to the macrophysical realities of the universe, which I think is a point to be taken in his favor. However, it seems to me that if nonconscious functioning replicas are logically possible, then the standardization of consciousness arising from on the level of a group mind is not only feasible but considered necessary and noncontingent. Thus, he appears to conclude that the epistemic asymmetric knowledge of consciousness that we have proves that consciousness cannot be logically supervenient, because a logically supervenient property would be demonstrable on the basis of external evidence, whereas we arrive at our concept of consciousness based on our first-person experience. After consulting the internet it appears that this is in fact theoretically possible, even if our concept of consciousness comes through first-person experience; however, this remains a highly debated topic with significant philosophical challenges, particularly regarding the nature of consciousness itself. In fact, this has become the key argument within the philosophy of mind, particularly regarding the debate on whether consciousness is explained by physical processes in the brain.

The bottom line is that the frontiers for the advance of the new sciences, including artificial intelligence, virtual reality, gene editing and quantum science, have effectively rendered a change in our conception of knowledge itself. These are the high-level phenomena that render ideas like consciousness in a way that they can no longer be explained by western science, whose model for understanding is the analysis of structure and function. Based on Chalmers' position as he advocates in this book, we are determined that the knowledge gained through a learning-model appertaining to structure and function, the twin models of western liberal science, as it has properly evolved to this point, are no longer suited for the explanation of high-level phenomenon such as consciousness. This notion is directly related to the problem of what is the scientific model necessary for advanced generative intelligence (AGI) to be created? At this point we ought to note that, for all the seemingly sophisticated thought and language, our language-game inhabits a moral space born of indifference and unintelligence. ChatGPT and other artificially intelligent chatbots do not include moral points of views, moral beliefs or the ability to make moral judgments. This makes the limitations of current AI technologies, coupled with the profound challenges of replicating the evolutionary processes that shaped human intelligence and, indeed, consciousness itself, make the prospect of AGI highly improbable. That's because cognition, or the ability to observe, learn and gain new insight, is incredibly hard to replicate through AI on the scale it occurs within the human brain.

So even if AGI is not feasible at this point in our scientific ambitions to realize an actual postmodern world, then what can we say about how consciousness itself came to be realized in its present form? Chalmers indicates that Frances Crick and Christopher Koch have discovered, through the science of neurobiology, that consciousness arose through the evolution of the human capability to produce 40-hertz oscillations, arising in the visual cortex and elsewhere in the brain of the human subject, as the fundamental neural feature responsible for conscious experience. Thus, an evolutionary model based on the schematic of this etiology has been constructed and legitimized. Do we need to go further? Chalmers has one final trick up his sleeve, it appears. In fact, to bolster support for this theory, he also tells us of Roger Penrose, who speculated that consciousness arose through what was ostensibly a process of decay; specifically the collapse of microtubules in the brain consequently led to the revoking of an end-stage mirrorlike development in the stable conceptualization of the self, as revealed in the feeling of existential dread the permeated the post-war dream of American hegemony. Which of the two processes -- or both, or neither of them -- should be considered the more likely fulcrum in the course of these pathologies, Chalmers declines to tell us.

I believe that the conclusion can be pointed to in Quine's ontological relativism, where he gives a clear answer to the rather natural question of whether his thesis of nondetermination is a form of relativism, saying "we can treat of the world and its objects only within some scientific idiom, this or another; there are others, but none higher. Such, then, is my absolutism. Or does it ring relativistic after all?" Personally, I think a suitable answer to the ontological relativity posed by the proposed technology of AGI contains a direct answer to a question that Quine might give in response to the problem we have formulated. What makes sense is not to say what the objects of a theory are, absolutely speaking, but how one theory of objects is interpretible or reinterpretible in another language-philosophy. It is thus meaningless to say which of the various possible models of our theory-form is our real or intended model. Yet even here we can make sense of there being many models. For we might be able to show that for each of the models, however unspecifiable, there is bound to be another which is a permutation or perhaps a dimunition of the first model which appeared to defy our logic. Three stars.

[Jafar · Rating 4 out of 5]

He rejects materialism and subscribes to property dualism. A great book by a mathematician turned philosopher.

[Oliver · Rating 1 out of 5]

A lot of words that ultimately say… very little.

Don’t read. Worthless.

[2007]

La storia del dualismo nella filosofia analitica della seconda metà del Novecento inizia con Naming & Necessity. Dopo aver sviluppato una teoria che distingue tra necessità e apriorità, Kripke sostiene che le identità teoretiche, ad es., della chimica (acqua = h2o) sono un esempio di necessità a posteriori (la nostra conoscenza di esse dipende dall'investigazione empirica, ma, poiché entrambi i lati dell’identità sono occupati da designatori rigidi (cfr. anche Putnam), essa risulta vera in tutti i mondi possibili). L’“illusione di contingenza” che sembra connotare questo enunciato, sostiene Kripke, deriva dal fatto che, quando tentiamo di immaginare questo scenario, spesso ne descriviamo un altro – quello in cui una sostanza che possiede tutte le proprietà superficiali dell’acqua (scorre nei fiumi, è un liquido trasparente, etc.) non è h2o, bensì una sostanza xyz. A questo punto, il filosofo si domanda se è in gioco un bias simile quando consideriamo la possibilità di una teoria dell’identità mente-corpo (Smart 1956):
(MC) Per ogni stato fenomenico F, F è identico a una proprietà neurofisiologica N.
Il punto è semplice: ciò che accade quando immaginiamo di essere in un certo stato fenomenico (ad esempio, avere la sensazione di un rosso vivido nel campo visivo) senza istanziare la corrispondente proprietà neurofisiologica non è equivalente a ciò che accade nel caso delle identità teoretiche a posteriori. Questo è dovuto al fatto che i nostri concetti fenomenici si riferiscono alle corrispondenti proprietà (fenomeniche, siano esse in definitiva fisiche o meno) in modo essenziale: non esiste un mondo possibile dove mi sembra di essere nello stato fenomenico F ma non lo sono. Questo è motivato dall’insight cartesiano per cui ciascuno di noi possiede un accesso epistemico privilegiato alla propria mente. (Uno potrebbe dire: posso immaginare che il calore non sia identico al movimento delle molecole. Kripke risponderebbe che in tal caso ciò che uno immagina è che la sensazione del calore non sia identica alle molecole, e questo scenario è metafisicamente possibile.) Da ciò:
(P1) Posso concepire dissociazioni continue tra stati neurofisiologici e fenomenici.
(P2) Se p è concepibile, allora è possibile.
(P3) L’identità è necessaria.
Dalla congiunzione delle premesse segue che gli stati fenomenici, dopotutto, non sono identici a stati neurofisiologici. Una prima, incoraggiante replica da parte dei fisicalisti (che dopotutto Chalmers stesso accetta sul piano nomologico) è che la base “biologica” presupposta da Smart e affini è inutilmente forte: soltanto uno sciovinismo di principio può spingerci a rigettare la possibilità che gli stati mentali siano equivalenti a stati funzionali realizzabili da qualsiasi sistema fisico. Uno stato funzionale è identificato in base al ruolo causale che occupa e due sistemi sono funzionalmente identici se e solo esiste un mapping completo tra gli stati dei due sistemi e se questi stati posseggono le stesse relazioni logiche rispetto agli altri stati del sistema. Facendo un esempio, per un funzionalista un sistema è nello stato fenomenico se è soggetto a un input luminoso rosso e la conseguenza di ciò sono specifiche testimonianze verbali (“L’oggetto davanti a me è rosso”) o di altra natura, in ogni caso (almeno teoricamente) identificabili dal punto di vista obiettivo della terza persona.
The Conscious Mind è innanzitutto una critica al funzionalismo metafisico, che, in una misura o nell’altra, è la posizione ortodossa nella filosofia della mente contemporanea. Chalmers sviluppa diversi esperimenti mentali per sostenere una forma di “dualismo funzionalista,” in cui i pregi della teoria sviluppata da Putnam e altri sono relegati sul piano nomologico: il principio di “invarianza organizzativa” ci dice che gli stati mentali sopravvengono naturalmente su quelli funzionali, mentre gli esperimentali mentali degli zombie e dello spettro invertito ci suggeriscono, secondo Chalmers, che il reame fenomenico non sopravviene metafisicamente su quello fisico. La distinzione è importante, almeno per buona parte di chi partecipi al dibattito sulla coscienza: le proprietà-A sopravvengono metafisicamente su quelle-B se e solo se, in ogni mondo metafisicamente possibile, non c’è variazione nelle proprietà-A senza variazione nelle proprietà-B. (Tralasciando la distinzione tra sopravvenienza locale e globale; cfr. Kim). Poiché i fisicalisti credono che la natura del mondo sia esclusivamente fisica (ma chi decide fino a dove si applica l’aggettivo?), la tesi della sopravvenienza metafisica è ciò che devono difendere, dal momento che la sua falsità implicherebbe che, dopotutto, il mentale e il fisico sono due cose concettualmente distinte. (Personalmente, non sono sicuro che la nozione di sopravvenienza sia quella corretta per impostare il dibattito, come hanno notati molti autori: la sopravvenienza è riflessiva e “superficiale,” in quanto si limita a evidenziare una correlazione sistematica tra due tipi di proprietà, senza fornire spiegazioni metaphysically thick del perché sono correlate così. Cfr. Schaffer.)
Per spiegare il modo specifico in cui Chalmers difende le sue posizioni, occorre introdurre il framework teorico in cui le sviluppa, cioè la semantica bidimensionale: a ogni termine sono associate due intensioni, cioè funzioni che mandano una coppia in un’estensione. L’intensione primaria vuole catturare il fenomeno dell’illusione di contingenza abilmente descritto da Kripke e rappresenta il “significato” del termine valutato a priori dalla prospettiva del mondo attuale: l’intensione primaria del termine “acqua,” perciò, corrisponde all’incirca a “la sostanza liquida e trasparente che scorre nei fiumi e riempie i mari.” L’intensione secondaria, invece, si ottiene rigidificando la descrizione che associamo aprioristicamente con un termine, cioè (all’incirca) la sua intensione primaria. La rigidificazione può essere intesa come l’applicazione di un dimostrativo rigido à la Kaplan: Chalmers nota correttamente che le necessità kripkiane sono fondate su questo implicito elemento indessicale. Notiamo la differenza: sotto l’intensione primaria di “acqua,” è vero a priori che l’acqua sarebbe potuta non essere h2o (in qualche mondo possibile, infatti, la sostanza liquida e trasparente è xyz).
La strategia di Chalmers è dunque quella di classificare tutte le necessità a posteriori (ci sarebbe da fare un discorso analogo per le contingenze a priori ma vabbè) come enunciati che raffigurano una “possibilità primaria” ma non secondaria (cioè: enunciati raffiguranti possibilità metafisiche sotto la lettura primaria delle intensioni dei termini, ma non sotto quella secondaria). Si tratta fondamentalmente di un metodo attraverso cui difendere l’approccio “razionalista” in epistemologia della modalità: una volta tracciate le distinzioni appropriate tra le diverse intensioni di un termine (e dunque di un enunciato), le necessità epistemiche coincidono con quelle metafisiche e l’apriorità è di nuovo una guida alla possibilità. In particolare, se riusciamo a determinare che qualche enunciato è secondariamente concepibile, allora sarà metafisicamente possibile.
Si diceva degli argomenti chalmersiani. Uno zombie è un sistema molecola per molecola, funzionalmente identico a me: quando osserva un fiore, dice “Che bello!”, si avanza per raccoglierlo e sorride mentre i suoi bulbi oculari ruotano verso di esso; tuttavia, uno zombie non possiede alcuna coscienza fenomenica, nel senso per cui “essere zombie,” da un punto di vista interiore, non significa nulla. Lo zombie interagirà col mondo esterno in un modo per tutto simile al mio senza però avere alcun contenuto esperienziale. Uno scenario simile è logicamente coerente? Secondo Chalmers, se uno risponde di sì è costretto a concludere che nel mondo c’è qualcosa in più di mere proprietà descrivibili dalla fisica (per quanto avanzata possa essere). Il punto di questo esperimento mentale è che i concetti fenomenici hanno una natura particolare: la loro intensione primaria sembra coincidere con quella secondaria (riprendendo l’argomento di Kripke, se qualcosa sembra dolore, allora è dolore: ci riferiamo al referente essenzialmente). Se questo è vero, allora possiamo determinare a priori che una proprietà fenomenica qualsiasi (ad es., vedere un computer nero) non è metafisicamente equivalente a qualsiasi set di attributi fisici o funzionali possiamo concepire: questo segue dalla concepibilità di uno zombie. L’argomento dello spettro invertito funziona in modo simile: è concepibile che un sistema molecola per molecola, funzionalmente identico a me abbia qualia rosso vivido dove io ho l’esperienza del blu, e via dicendo per tutti i colori: esiste un mapping completo tra i miei stati mentali e i suoi che preserva i rapporti causali di ciascuno di essi rispetto al proprio sistema e agli input e tuttavia non siamo fenomenicamente identici! A priori, il mentale non sopravviene metafisicamente sul fisico.
Per quanto mi riguarda, in definitiva non mi sembrano argomenti molto convincenti. In primo luogo, ci sono buone ragioni per credere che la nostra giustificazione epistemica per affermare di non essere zombie sia semplicemente una petitio principii contro l’eliminativista (se non ricordo male, Chalmers introduce la nozione di giudizio fenomenico come parzialmente costituito dall’esperienza fenomenica stessa, quando Dennett probabilmente rigetterebbe lo stesso punto). In secondo luogo, se ammettiamo che le dissociazioni tra funzionale e fenomenico siano logicamente coerenti, accettiamo che uno possa, in linea di principio, possedere concetti fenomenici senza avere le corrispondenti capacità riconoscitive: è logicamente possibile che uno zombie “part-time” sia diventato cosciente soltanto un istante fa e ciò che ora riconosce tranquillamente come “rosso” in realtà, per tutta la sua esistenza, era ciò che esperiva come verde. (Oltre agli altri scenari in cui la dissociazione funzionale-fenomenico non involve strutture fenomenologiche “insensibili” all’inversione come il campo cromatico e il fenomenico sembra molto più dipendente dal fisico: si consideri un neonato col campo del piacere fisiologico invertito; nonostante le urla, i pianti e il sangue colante, prenderlo a martellate gli sta provocando un benessere così grande che non riesce nemmeno a esprimerlo, perché ops, questo implicherebbe avere differenze funzionali e perciò, tutto sommato, il fenomenico dipenderebbe dal fisico). (La domanda del perché le nostre strutture fenomenologiche siano così piuttosto che in un altro modo rimane profonda e forse richiede una spiegazione bruta, come per quanto riguarda i fatti indessicali. Qui occorrerebbe una terapia wittgensteiniana.)
Inoltre mi sembra che il principio di invarianza organizzativa non sia giustificato a sufficienza. Uno può accettare ciò che implica la semantica bidimensionale rilevando in ogni caso che le questioni di modalità nomologica non sono stabilite attraverso esperimenti mentali, bensì investigazioni empiriche; e, poiché in linea di principio gli zombie o gli invertiti sono funzionalmente identici a noi, siamo costretti ad accettare che siano nomologicamente possibili. Questo è soltanto un altro modo di esprimere il fatto che l’epifenomenalismo implica troppi scenari scettici per un agente epistemico. D’altro canto, supporre che l’universo non sia causalmente chiuso sotto principi fisici è un’assunzione filosofica semplicemente bizzarra. Concludo che l’unica alternativa plausibile al fisicalismo non-riduttivo sia qualche forma di panpsichismo, anche se prima facie non mi sembra proprio un’ipotesi interessante. “Ma quindi la possibilità logica implica possibilità nomologica?” No, però solitamente nel processo cognitivo uno procede assumendo la possibilità nomologica fino a prova contraria. La teoria della relatività Einstein, ad esempio, ha bloccato una di queste presunte implicazioni (sul limite della velocità della luce), ma si è trattata di un’impresa (parzialmente) a posteriori.
Per ciò che ho letto, ci sono un sacco di ottimi argomenti contro la concepibilità o l’impiego degli zombie nella filosofia della mente (particolarmente Balog e Tye), anche se probabilmente sarebbe interessante sapere se esiste della letteratura epistemologica a riguardo, perché teorie abbastanza rilevanti su come otteniamo conoscenza modale – come quella di Roca-Royes, fondata sulla nozione di “similarità” tra controparti epistemiche (ovviamente, è molto empirically-based) – non sembrano essere capaci di analizzare gli scenari proposti per gli argomenti dualisti. Una cosa è certa, nemmeno Chalmers è così convinto delle repliche che offre contro chi obietta che accettare soltanto il principio di invarianza organizzativa è una mossa ipocrita e inconsistente, in quanto le definisce “altamente plausibili,” o qualcosa di simile. Se uno accetta la possibilità logica di questi scenari, è difficile bloccare tutti gli scenari bizzarri che lo stesso dualista pone sul piano meramente logico della modalità. In alternativa, un dualista deve spiegare a certi fisicalisti particolarmente impuntati sulle leggi di natura (come Shoemaker) perché la modalità metafisica non collassi su quella nomologica in una teoria più generale che spieghi come otteniamo credenze modali stabili.
Un’ulteriore esperimento mentale a favore del dualismo, altamente citato negli anni e logicamente indipendente da quelli sviluppati da Chalmers, è il cosiddetto “argomento della conoscenza” di Jackson (che successivamente lo rigetterà da fisicalista pentito, comunque). Una neuro-oftalmologa (esiste? una neurologa che è anche oftalmologa) nasce, cresce e studia come l’essere umano percepisce i colori per i primi trent’anni della sua esistenza completamente chiusa in una stanza i cui muri sono bianchi e il soffitto è nero, mentre l’arredamento e i soprammobili sono o bianchi o neri e così via. Supponiamo che Mary, questa neuro-oftalmologa, un giorno esca dalla sua stanza e veda una mela rossa. È legittimo credere che abbia scoperta qualcosa di nuovo con questa esperienza. Ma allora Mary, nonostante sapesse (per ipotesi) ogni fatto fisico sulla natura dei colori e sulla percezione umana, ha imparato qualche fatto ulteriore attraverso l’esperienza – qualche fatto fenomenico, non-fisico.
Una strategia classica contro questo argomento è stata quella inizialmente adottata da Lewis, che consiste nel sostenere che Mary ottiene soltanto una forma di knowledge-how e non knowledge-to. In realtà la proprietà sembra descrivibile abbastanza bene, qualcosa nelle linee di “la proprietà x tale che vedere rosso è x per Mary.” In un certo senso, è molto intuitivo dire che la conoscenza di Mary sia relativa al come piuttosto che al che cosa; tuttavia, l’analogia con (ad es.) il saper-andare in bicicletta si spezza poiché quest’ultima abilità non denota uno stato mentale completo, intero; il sapere-com’è il blu ha indubbiamente una natura qualitativa ben definita, perciò sembra corretto inferire la presenza di corrispondenti proprietà sui generis. L’unica alternativa plausibile per il fisicalista è sostenere che la necessità metafisica che connette la mente e il corpo sia a posteriori – purtroppo, però, abbiamo già visto che le identità kripkiane non possono fungere da esempio, perciò occorre postulare una teoria più espansiva, in grado di spiegare entrambi i fenomeni. Questo è il cosiddetto fisicalismo a posteriori.
Chalmers è dubbioso sulla plausibilità di questa tesi, in quanto ritiene che la sua semantica bidimensionale provveda gli strumenti necessari e semplici per connettere modalità epistemica e metafisica, e che ciò sia sufficiente per rendere falsa l’ipotesi materialista. I fisicalisti a posteriori possono difendersi percorrendo diverse vie, credo: (a) sostenere che le leggi di natura siano metafisicamente necessarie (cfr. Armstrong, Bird); (b) riformulare un’epistemologia della modalità empirista che limiti grandemente ciò che è concepibile (o impieghi la nozione di “mondo impossibile”); (c) mantenere la dissociazione concettuale tra funzione ed esperienza renda impossibile l’accesso privilegiato ai propri stati fenomenici (Pauen).
Senza prendere una posizione riguardo alla complessa questione sulla legittimità dell’epistemologia di Chalmers (la metafisica è davvero una ricerca attorno al nostro spazio concettuale? in tal caso com’è possibile svelare fatti sostanziali sulla struttura della realtà facendo metafisica?), i suoi esperimenti mentali sono estremamente affascinanti per le ragioni evidenziate da Flanagan e Polger – mettono in crisi qualsiasi esplicazione evoluzionistica si sia fornita della coscienza, in particolar modo per certe strutture fenomenologiche (il campo cromatico!). Esiste tutta una serie di argomenti anti-funzionalisti basati sulle più concettualmente oscure inversioni di campo (sonoro rispetto a visivo, etc.) cui un fisicalista deve replicare se vuole difendere la tesi che l’esperienza è soltanto funzione.
Questa era la sezione più prettamente filosofica del libro – ne segue una volta a identificare quelli che dovrebbero esseri gli assiomi di qualsiasi teoria della coscienza appropriata e una che connette le problematiche dell’interpretazione della meccanica quantistica al problema della coscienza (in particolar modo, Chalmers sostiene che l’interpretazione “a molte menti” di Everett, oltre a essere una soluzione elegante, plausibile e suscettibile di falsificazione, riceve supporto indipendente dall’assunzione filosofica del dualismo).

[Agnes · Rating 4 out of 5]

Ta książka absolutnie zafascynowała mnie filozofią umysłu. Zawiera niezwykle ciekawe pomysły i są one przedstawione z różnych perspektyw. Argumenty bronione są z taką konsekwencją, że aż można się zmęczyć ich szczegółowością - i to jest problem tej książki. Usłyszałam raz, że David Chalmers mógłby powiedzieć to co chciał powiedzieć w o połowie krótszej książce i choć z początku nie zgadzałam się z tą opinią i doceniałam szczegółowość jego wywodu to już w drugiej części tej lektury ilość detali i wątków pobocznych mnie przytłaczała.
Część druga tej książki wydaje mi się również gorsza merytorycznie, jest też nieco mniej filozoficzna (i może przez to jest tu problem?). Możliwe że jest to również spowodowane tym, że sam autor najbardziej pewny jest swojej argumentacji na rzecz dualizmu, a swojej teorii świadomości już mniej (co sam przyznaje na końcu książki). Podzielam jego opinię - pomysł na obalenie materializmu jest bardzo ciekawy i dobrze wytrzymuje siłę kontrargumentów (choć ja osobiście nie do końca zgadzam się z autorem w szczegółach tejże argumentacji). Myślę, że gdyby ta pozycja składała się tylko z 1 części to otrzymałaby ode mnie 5/5. Niemniej, druga część tej książki również jest intrygująca i stawia ciekawe propozycje dotyczące teorii na temat świadomości. Nie przekonuje mnie jednak argument dotyczący ,,blaknących" i ,,tańczących" qualiów, a konsekwencje jakie z nich wyprowadza Chalmers również nie są dla mnie do zaakceptowania. Chyba w drugiej części najciekawsze były 2 końcowe rozdziały, a w szczególności ten który wiązał teorie świadomości z mechaniką kwantową. Cieszę się, że autor podjął tak szeroką gamę zagadnień i nie bał się tworzenia nawet nieintuicyjnych hipotez.

Z pewnością sięgnę po inne książki Chalmersa

[A. B. · Rating 5 out of 5]

A wonderful mind-blowing book. Provides a fresh and frankly thrilling overview of the problem of consciousness and mind. I enclose a brief summary of each chapter below.

In the Introduction, Chalmers notes three constraints. He will take consciousness seriously, not reducing it to an illusion; he will take science seriously; and he thinks consciousness is subject to natural, albeit not physical laws. He will defend a form of dualism, core to which is the notion of supervenience.

Chapter 1 begins by asking what consciousness is and notes that it is difficult to define. However, it may be glossed as the subjective character of experience or qualia. We make a distinction between the phenomenal and the psychological concepts of mind. The former is a subjective conscious experience, the latter is the causal or explanatory basis for behaviour. In the history of philosophy, from Descartes to Ryle to functionalism, these two have often been conflated. They should not be. All phenomenal properties co-occur with psychological properties. There is a distinction between phenomenal consciousness and access consciousness (awareness).

Chapter 2: Supervenience is when lower-level properties entail higher-level properties and can be understood in terms of them. Supervenience can be global (including the context of the world) or local. Phenomenal consciousness is probably locally supervenient on the facts of cognitive science. Logical supervenience is when the lower-level properties certainly entail higher-level properties; whereas natural supervenience is when lower-level properties may exist without higher-level properties being entailed by them. Reductive explanations are explanations of higher-level phenomena solely in terms of lower-level phenomena. Supervenience conditionals are of the form: 'If the A-facts about a situation are X, then the B-facts are Y'. These are conceptual truths. The meaning of a term is its intension, which can be primary ('water') or secondary ('H2O'). There are two varieties of logical supervenience depending on this distinction. Supervenience according to secondary intension is a posteriori. Primary intensions are a priori. Almost all facts supervene logically on the physical facts, including physical laws. Possible exceptions are conscious experience, indexicality, and negative existential facts. Every supervenience relation of a high-level property upon the physical is ultimately either logically or naturally contingently supervenient. If neither of these holds then it is likely that objective high-level facts of the kind do not exist (e.g. moral facts). The supervenience conditional is itself an a priori conceptual truth. Logical supervenience is the role and natural supervenience the exception.

Chapter 3: Is consciousness logically supervenient on the physical? Chalmers argues that it is not. He gives a few arguments for the same. First, zombies are logically possible. Second, it is conceivable that someone else would have a completely inverted colour spectrum but the same functional organisation. Third, epistemic asymmetry. We know consciousness only from our own experience, not empirical observation. Fourth, the Mary's Room argument. Fifth, there is no analysis of exactly how the entailment relation would work because one would need to analyse consciousness first, and there is no such analysis.
Next, Chalmers addresses some objections. He argues too against cognitive modelling, physics-based theories, neurobiological explanation, and evolutionary explanation. He concludes that none of these accounts can really explain the nature of conscious and therefore, the reductive explanation of consciousness is mistaken.

Chapter 4: Chalmers argues for naturalistic dualism -- a dualism that is consistent with the laws of nature, but the conception of such laws needs to be expanded to account for it. It is logically possible that there could be a world physically identical to others where consciousness does not exist. This proves the falsity of materialism. This could also be a sort of neutral monism but not a materialistic monism. He then explores some objections. Especially the objection that while a zombie world is logically possible, that is, conceivable; it is metaphysically impossible. He replies that there is no reason to believe that a modality exists whereby some possible worlds are metaphysically possible and some are not. Jackson's Mary's Room Argument or the Knowledge Argument against materialism is also explored and defended. Kripke argues from the possibility of disembodied pains and zombies in other possible worlds that materialism is false. Chalmers finds the disembodiment argument inconclusive, but the zombies argument to be profound.

Chalmers argues that his view is indeed a form of epiphenomenalism as it relies on a version of the causal closure of the physical principle which seems to make consciousness explanatorily irrelevant. This is further proof in favour of his naturalistic dualism. He rejects other theories of consciousness and its relation to matter. One of the interesting theories he rejects is interactionist dualism which states that consciousness might influence the gaps between physical processes. Just like Maxwell's discovery of electromagnetism made us reevaluate what 'materialism' meant, so there is a need to re-evaluate science to make room for consciousness.

Chapter 5:
Consciousness is phenomenal, cognition is psychological. But the two are linked in nomic manner. Phenomenal judgements are psychological judgements that make a system react and give a certain output in response to a certain input. There are three orders of phenomenal judgements. First-order: That's red. Second-order: I am having a red sensation now. Third-order: Sensations are mysterious. There arises a paradox of phenomenal judgement, consciousness seems explanatorily irrelevant. We can account for everything exclusively psychologically. Yet, conscious phenomenal experience is a brute fact to be explained. Some, like Dennett deny phenomenal experience, an absurd position. The explanatory irrelevance of experience to physical behaviour may seem counter-intuitive, but there are no strong challenges against it. Epistemologically, knowledge of other things is different from our knowledge of our own experience which is direct. There is an element in my belief which is not present in my zombie twin's belief. It is only functionally that our judgements are the same -- they do not involve the same belief.

Chapter 6: In order to have a theory of consciousness, we need certain psychophysical laws. This will not be as indubitable as the laws of physics but still prove a useful heuristic. The core principle of psychophysical interaction will be the structural coherence between phenomenal consciousness and psychological awareness. When we know what information a system has access to psychologically, we can understand what phenomenal consciousness it is undergoing. Thus, we might even know what bats are experiencing even if we do not have that experience ourselves! This is a form of nonreductive functionalism whereby the structure of psychological awareness is correlated in systematic ways with phenomenal consciousness.

Chapter 7 seeks to establish the principle of organizational invariance -- if a system has a certain functional organisation, it will give rise to consciousness. This is a form of nonreductive functionalism. Chalmers defends this through a series of thought experiments -- wherein he proved the implausibility of fading qualia (that a system's qualia would fade if replaced gradually by other materials) and dancing qualia (that a system would have different experiences if the materials processing sensory input were switched on occasion). Given their implausibility, the possibility of a system being organised functionally in a way that will give rise to consciousness and yet is not conscious would be metaphysically impossible.

Chapter 8 argues, in a slogan, that experience is information from the inside, while physics is information from the outside. It locates phenomenal and psychological properties as dependent on a shared information space that forms the structure of the world. This may be seen as a variant of panpsychism whereby all things are phenomenally conscious to the extent that the structure of their organisation allows.

Chapter 9 argues that strong artificial intelligence is very much possible. Chalmers addresses a number of objections to this thesis. Against the Chinese Room argument, he noted that a structural organisation will metaphysically necessarily give rise to consciousness. Against Searle's argument that computation is syntactic whereas minds are semantic, he notes that while programmes may be syntactic, their implementations are concrete systems with causal dynamics. Against the view that simulation is not replication, he invokes the principle of organizational invariance. Against the argument that computers are inflexible, while human minds are flexible, he notes that there are no in principle objections to flexibility in machines. Against the Gödelian argument that formal systems can have true sentences within them that they cannot prove, he replies that there is no reason to believe that humans can see the truth of those sentences either. Against the argument that mental processes are continuous, whereas computational processes are discrete -- he notes that a close approximation is as good as a real thing.

Chapter 10 mostly went over my head. However, I understand that Chalmers defends the Everett interpretation of Quantum Mechanics whereby the world is in a giant superposition of states and we are experiencing only the smallest substate of the world. This is different from Wigner's interpretation which states that consciousness brings about collapse, and Bohm's interpretation that there are nonlocal hidden variables.

[Hersh Sangani · Rating 5 out of 5]

Absolutely amazing philosophy book. Super recommended for anyone who wants to learn a shit ton of real philosophy on a broad range of topics and follow how a philosopher thinks through and defends a thesis. I don’t agree with everything but it is amazingly well defended and has definitely changed how I think of consciousness. Not accessible however to readers without at least some background in philosophy.

[Joshua Stein · Rating 3 out of 5]

So, there's a lot to be said about The Conscious Mind. The most important thing is that it is stylistically and structurally very strange. Chalmers argues for his version of property dualism from an angle that is not well represented or well appreciated in philosophy of mind: theoretical metaphysics. There is something wonderfully (in my opinion) anti-metaphysical about most of the literature in philosophy of mind; most of the folks in this field (Block, Damasio, Paul Churchland, Dennett, etc.) really think that these are questions ultimately adjudicated empirically. They're about the matters of fact of how brains and minds work, and how the two relate. It is Chalmers, a lonely soldier with an unrelenting enemy, who is arguing that we ought to seriously consider some metaphysical issues.

O.K. I'm exaggerating a bit; Chalmers has a few allies, but they aren't allies who should be comfortable. It's an odd way to attack a hard problem, and Chalmers' book was attempting to break ground on a new potential approach, with a rearticulation of the problem.

The book delves into Chalmers' articulation of the problem in the first few sections, and while it has some interesting observations about the metaphysics of mind and the philosophy of science, it makes some claims that are clearly going to be a problem for views later, claims about what sorts of relations we can genuinely attribute to mental states and brain states, and how they relate in terms of their general causal structure. Those who have read a lot of philosophy will see some serious speedbumps in Chalmers' future as he coasts through the middle chapters of the book.

They really come back to bite him when he gets into saying some interesting things about the empirical issues, about information and about the relation of accessible information to phenomenal consciousness. There are some really sensible and interesting things going on in Chalmers' discussion of information in Chapter 8, but it gets undercut by some weird entailments of his broader metaphysical view, and it is easy to see why deflationist theorists since Wittgenstein have been running from these grand sorts of metaphysical ideas.

I recommend the book for those who are interested in metaphysics and interested in philosophy of mind as a historical venture, but I have to admit, I'm unconvinced that this book matters to contemporary conversations in philosophy of mind. I don't think that Chalmers says anything that a philosopher of mind who believes strongly in the empirical program that works through most of the contemporary study should feel obligated to accept. Some of the observations in the later chapters are interesting, but the amount of material you have to wade through in order to get there is a non-negligible price.

The book is well written and interestingly argued; it has some cool ideas about how to do metaphysics in relationship to philosophy of science, but I think that it is also a good study in why exactly we should take seriously a bottom-up or mathematically oriented approach to metaphysics, rather than sort of a general conceptual methodology as we've seen in some areas in 19th and 20th century philosophy of science. There are parts towards the end where it looks like Chalmers is working to reductio himself (especially his discussion of panpsychism) and I can hear the groans of American philosophers of mind reading that material, wondering why these are conclusions that Chalmers is mentioning in the body of the book, rather than burying in the footnotes.

Anyway, Chalmers is a terrific philosopher and a terrific writer; for all of my grievances and serious programmatic differences, I can see why there are many philosophers with a peripheral interest in mind who utilize him when talking about particular issues (like epiphenomenalism) in the subfield.

[Zack · Rating 4 out of 5]

In an attempt at rigour and comprehensiveness it ends up longer, more repetitive, and dryer than it might otherwise be, and than Dennet’s Bacteria. https://www.goodreads.com/review/show...

Overall I find at least the starting contentions quite convincing, I mostly agree with that. I don’t agree with all the details early on; and less so towards the end of the book. I think there's a possibility that in the future there will be more progress towards a theory of consciousness than he implies at points. I’m not sure what I think about the comments about “materialism” and “naturalistic dualism”.

It may be that at some point there’s a theory developed which shows that, after all, it isn’t possible to have philosophical zombies. Presumably many theories of consciousness would do that. But perhaps the point is just that on current reductive theories we can’t say that.

Don’t think he’s quite right on epiphenomenalism (or on the closed nature of causation), epiphenomenalism seems dubious to me, though possibly correct. The critiques he surveys of epiphenomenalism seem strong.

His use of “god” as a heuristic device or thought experiment is a bit annoying: though he clearly is an athiest.

I ultimately think he’s too strong in ruling out the possibility that it might be found, at some point, that there is a logical supervenience of consciousness on the physical; and consequently that, with such an understanding, philosophical zombies physically identical to conscious beings is logically impossible.

He may be right that with consciousness, every possibility has a problem.

The paradox of third level commentary, commentary about the strangeness of consciousness, suggests that consciousness itself has some causal efficacy. This is a novel way of posing it and seems pretty powerful to me.

His way out of the explanatory irrelevance argument by claiming that casual justification for our belief in why we are conscious isn’t the right kind (of justification? explanation? Answer? response?) seems a bit wrong to me, a bit of a sleight of hand. More generally, I’m increasingly feeling that he’s convinced me that while a zombie world may be conceivable, may seem logically consistent, so supervenience seems naturally but not logically necessary, that may well be an epistemic rather than ontological consideration. That is, if we actually had a fully described world in which the physical reality and the laws were the same, identical consciousness, identical qualia would be logically inevitable. At least as much as if we imagine all the microphysical states and laws being the same, the macrophysical states are logically inevitable.

His willing embrace of the supposed casual irrelevance of consciousness seems almost though not quite as absurd as eliminativism.

Thought provoking overall.

I'm not sure if his moves towards a theory of the psycho physical laws will cash out much.

Seems a bit thin on this and not necessarily well argued.

A lot of preamble to his sketches towards such a theory.

Could use the insights from phenomenology quite well i think: this is missing.

Claim that awareness is necessary for consciousness seems a bit dubious to be. Not sure if he's claiming it's sufficient but…

Claim that a “psycho-physical fact” as a bridge fact (briefly: between natural laws and an understanding of consciousness etc.) is sufficient awaits a convincing candidate. Otherwise I'm not sure he can insist it is sufficient.

His description of “functional organisation” of a system and equivalence in terms of causal structure is useful, better than some who leap straight to computational or information theoretical equivalents.

His assumption that a neural level is a high enough level of causality seems (wildly) implausible to me.

The concept of functional invariance, that a functional equivalent gives rise to a conscious identical experience seems correct to me, even if, beyond identical situations, the relationship is quite unstable, a slight change in functional may give a larger change than expected in consciousness.

Think he overstates rationality slightly. I think the argument against behavioural invariance analogy, while I ultimately agree, needs beefing up a little. I don’t see why an incremental look-up table is logically impossible (without consciousness).

I don’t see the problem in itself with the dancing qualia happening, aside from previous is arguments (aside from what? Not sure what I was trying to say). Would it not change the memories too? …

He moves too fast on AI. His ambitions for the (psycho-physical?) laws seem a bit strong but maybe that's just in principle.

He moves too fast, I think, to seeing a fundamentalness in information. I think there’s a social and sociological explanation for the drive to see everything in terms of information: capitalist transformation into everything as measurable exchange value; a drive to measure things; the amazing apparent powers of computers. But it seems incomplete and limited, and a way of framing the world, which we have no reason to believe the actual world is limited to. (I want to read more on this.)

It sounded though I may have not been paying attention closely enough, that he was implying there’s a 1:1 correlation in *both directions* between physical organisational structure and phenomenological structure. Surely that can’t be right though, he’s demonstrated and I think it is persuasive that a given physical causal functional organisational structure determines a particular phenomenological structure. But no reason to think that a given phenomenology can only be instantiated in one particular functional organisation. I doubt he’d think this.

I think his move to seeing reportability of consciousness as key to a theory of consciousness is not really explained, is not necessarily true, and seems an over-concession to (perhaps) linguistic similarity in the terms, or to Dennett, or to something else.

All information is conscious? Gone a bit wild here. A simple thermostat is conscious? No. He's maybe too pessimistic about the ongoing difficulty in identifying consciousness, in further studies of the brain to illuminate anything. It clearly exists in humans, and seems pretty likely not in thermostats. But…

Is it just about complexity? Or something else?

The rock/thermostat distinction doesn't hold up and seems to me to be a bit anthropocentric, untenable as such.

He thinks that other consciousness experiences arising from other areas of our brain that we aren't aware of is more counterintuitive than the thermostat. That's bonkers: it is far far less counterintuitive, to me.

I'm more sceptical about the “it from bit” thing than I maybe was.

He holds some things and gets some things right that Dennet doesn’t, but also he gets some things wrong and misses some things that Dennet gets right. The fundamental thing he gets right is in the insufficiency of Dennet’s view, though even in details he doesn’t cash that out quite right.

He talks as if he has a very sketchy and insufficient theory. But I think he just he hasn’t got a theory, so much as some thoughts about and desidera for a theory. Maybe that’s as far as is possible, now at least. But he overblows it.

The first stuff on AI seems odd to me. Mostly people want it to perform certain functions, and consciousness is not what they’re aiming for or hugely concerned with.

Are there physical laws that are not directly computable? Seems possibly, perhaps likely. (The three body problem as a basic example of something which isn’t analytically computable but requires iterative calculations? I guess this is more to do with chaos, perhaps. I should think more about this and other examples.)

His account of casual organisation being formalised in computational organisation seems, indeed, reasonable. But his understanding of information as "differences that make a difference" is converting analogue, or continuous, into digital or discreet. Epistemologically may be possible (up to an arbitrary level of exactness) but no reason to think that ontologically it holds.

His response to the Chinese room idea (if I've understood correctly) is a bit confused in outcome through in his thinking just assuming the same casual relations are used or necessary to recreate the same input-output. Surely quite a high degree would be possible with very much thinner causal relations.

Here I think it's falling back, perhaps, on Turing test ideas. Understandable but limited.

In a broad agreement on quantum interpretations and consciousness.

Superposed minds a bit less persuaded.

Brain indexicality seems correct. I see no difficulty.

To be fair, an information theoretical approach to a lot of things has proved quite fruitful. From thermodynamics to conservation laws. Think more on this.