Let's Read: Facing Up to the Problem of Consciousness (1995), by David Chalmers

Facing Up to the Problem of Consciousness (1995) is a famous paper by David Chalmers, and it talks about the easy problem of consciousness, the hard problem of consciousness, a sketch of how "usual" attempts to solve the hard problem fails, and how it might be solved.

Chalmers did a TED talk about his ideas. A Let's Read to the paper itself follows.

The easy problems and the hard problem

The easy problems of consciousness are those... phenomena explainable in terms of computational or neural mechanisms.

 Some "easy" problems are:

the focus of attention

the difference between wakefulness and sleep

the ability of a system to access its own internal states

The hard problems are the problems that are not easy.

The main problem of consciousness is "Why does consciousness exist?".

... an organism is conscious if there is something it is like to be that organism, and a mental state is conscious if there is something it is like to be in that state. Sometimes terms such as "phenomenal consciousness" and "qualia" are also used here, but I find it more natural to speak of "conscious experience" or simply "experience".

Here, Chalmers distinguishes between "awareness" and "consciousness". "Awareness" for the functional parts of consciousness, for how it works. "Consciousness" for the inner feeling of consciousness.

The easy question is for awareness. The hard problem is for consciousness.

Functional explanation

We know how to explain how something works. We don't know how to explain how something feels. That's why the easy problem is easy and the hard problem is hard.

... if someone says "I can see that you have explained how information is discriminated, integrated, and reported, but you have not explained how it is experienced", they are not making a conceptual mistake. This is a nontrivial further question.

Why doesn't all this information-processing go on "in the dark", free of any inner feel? Why is it that when electromagnetic waveforms impinge on a retina and are discriminated and categorized by a visual system, this discrimination and categorization is experienced as a sensation of vivid red? ... There is an explanatory gap (a term due to Levine 1983) between the functions and experience...

"in the dark" is to be a "philosophical zombie". Personally, I suspect that we are philosophical zombies, and the real question is why humans think that humans are not philosophical zombies.

The p-zombie: Pinkie zombie, or Pony zombie?

Some case-studies

Chalmers considers a few theories of consciousness and shows they are not.

1. Some explain something else. They usually deal with the easy problems.
2. Some deny the phenomenon. They claim the hard problem is not a real problem, and thus has no need for answer. Chalmers thinks the hard problem is real, so he disagrees.
3. Some claim to be explaining experience. This but actually only explains awareness.
4. Some explain the structure of experience, for example, that for a dog, the colors of the world has only 2 dimensions. This is useful but not enough.
5. Some isolate the substrate of experience. Basically, this is what "neural correlate of consciousness" is about, finding out what physical systems are conscious in what ways. Such a theory would, for example, take a look at two brains, one sleepwalking and one wokewalking, and figure out which is conscious. Chalmers still thinks it's not enough.

The extra ingredient

New ideas must be used for explaining consciousness.

To account for conscious experience, we need an extra ingredient in the explanation... chaos and nonlinear dynamics... nonalgorithmic processing... quantum mechanics... 

Perhaps the most popular "extra ingredient" of all is quantum mechanics. The attractiveness of quantum theories of consciousness may stem from a Law of Minimization of Mystery: consciousness is mysterious and quantum mechanics is mysterious, so maybe the two mysteries have a common source.

Law of Minimization of Mystery my flank

Chalmers disclaimed them all, because they are not mysterious enough. That is, they are still functional. They can explain how consciousness function, but not why it feels. The same for any "physicalist" explanation.

For any physical process we specify there will be an unanswered question: Why should this process give rise to experience? Given any such process, it is conceptually coherent that it could be instantiated in the absence of experience. It follows that no mere account of the physical process will tell us why experience arises. The emergence of experience goes beyond what can be derived from physical theory.

Here's the zombie argument again. Chalmers claims that

1. There can be a world that's exactly the same in all its physical laws and still have only philosophical zombies.
2. We are not philosophical zombies.
3. Thus, physicalism is false.

Nonreductive explanation

Since physics can't explain consciousness, to explain consciousness, we have to include consciousness as fundamental in our physics. Make consciousness as fundamental as spacetime and mass. Once we do that, and add some axioms of consciousness, the hard problem can be solved.

Of course, by taking experience as fundamental, there is a sense in which this approach does not tell us why there is experience in the first place. But this is the same for any fundamental theory... A theory of matter can still explain all sorts of facts about matter, by showing how they are consequences of the basic laws. The same goes for a theory of experience.

Outline of a theory of consciousness

Chalmers gropes around for how such a theory of consciousness should be like.

Raw data for the theory: introspection, verbal description from other people, etc.

Tools for the study: thought-experiments, philosophy, mathematical elegance/simplicity, 

Chalmers guesses 3 possible psychophysical principles: rules for what a physical system would feel. First two he considers necessary, and the third, speculative.

The principle of structural coherence

... wherever we find consciousness, we find awareness. Wherever there is conscious experience, there is some corresponding information in the cognitive system that is available in the control of behavior, and available for verbal report. Conversely, it seems that whenever information is available for report and for global control, there is a corresponding conscious experience... It is this isomorphism between the structures of consciousness and awareness that constitutes the principle of structural coherence.

In mathspeak, awareness is isomomorphic to consciousness.

If this is true, then it'd mean that as we solve the problem of awareness, we would also solve the physical basis of consciousness. So for example, if we figure out which kind of physical system can distinguish electromagnetic wavelengths, we will also figure out that it is the kind of physical system necessary in any conscious experience of color.

Chalmers seems to regard consciousness as the "semantics" for the syntax of awareness. As such, he admits the possibility of a consciousness that experiences red and green in the opposite way but in a functionally isomorphic way.

The principle of organizational invariance

... any two systems with the same fine-grained functional organization will have qualitatively identical experiences. If the causal patterns of neural organization were duplicated in silicon, for example, with a silicon chip for every neuron and the same patterns of interaction, then the same experiences would arise.

In mathspeak, two consciousnesses are identical if they are isomorphic to isomorphic awarenesses. 

This, in particular would mean that mind-uploading is definitely possible provided that the computer simulates your brain's exact functions [Chalmers doesn't talk about whether a consciousness would remain the same after significant functional reorganization of awareness. Presumably it'd be a problem for future consciologists.]. And also that it'd be impossible, for example, to "flip a switch" in your consciousness so that you perceive red and green oppositely, without also changing how your brain functions.

The argument Chalmers did is the "gradual uploading" argument:

• Suppose there exists two functionally isomorphic physical systems A, B, that has two different consciousnesses a, b. For example, A is you, and B is you but with red and blue switched (inverted qualia). 
• Then if we switch A to B part-by-part (as in mind-uploading by gradually changing each neuron into an electronic substitute), consciousness would remain the same all the way, because otherwise it would feel something has changed and would "cry out in surprise", which would function differently from the original consciousness, since the original consciousness would not cry out in surprise.
• But we already assumed that the physical systems don't function differently ever, contradiction.

There are a few ways to attack this argument.

• It's possible that a and b are "simple consciousnesses", that is, A and B has no parts at all, and there's no way to be gradual about this. Some people actually think God has no parts (divine simplicity).
• Once we recognizes this possibility, we see that even gradual switching is not that different. Switching from A to B in one step, or 100 steps, isn't that different. Imagine if in the first 99 steps, going from A to (0.01A + 0.99B), there's no change in consciousness, but in the very last step, to B, the consciousness suddenly switches to b. It's certainly conceivable, even if it sounds rather dumb.

Chalmers though, for all his talk about the fundamental importance of qualia, does not consider this "dancing qualia" relevant.

It is a central fact about experience, very familiar from our own case, that whenever experiences change significantly and we are paying attention, we can notice the change; if this were not to be the case, we would be led to the skeptical possibility that our experiences are dancing before our eyes all the time.

In other words: who cares if I'm a philosophical schizophrenic? As long as I'm not a philosophical zombie. 

In effect, Chalmers is claiming that feelings/qualia exists, but all we can ever know is the relationship between the feelings, and that's just fine. Two consciousnesses are the same if they are isomorphic. That is, if I experience all red and blue invertedly, I would be the same me, because I would be isomorphic to the me before the qualia inversion.

Which to me means it should be revised to this:

Two consciousnesses are identical if they are isomorphic.

Or:

Consciousness is fully defined by the structure of it.

The basic building blocks are irrelevant.

The double-aspect theory of information

Here Chalmers considers the basic building blocks of consciousness. The first two principles were simply about how consciousness is built up from parts. 

Since information can be represented in many different kinds of physical stuff, like how you can make a computer out of silicon or carbon, this sounds a lot like how consciousness can be represented in many different kinds of physical stuff, too.

Also, consider the idea of it from bit, that is, physics is fundamentally about information...

So... maybe information is all there is to it. Information makes up the physical world, and makes up consciousness. 

We are led to a conception of the world on which information is truly fundamental, and on which it has two basic aspects, corresponding to the physical and the phenomenal features of the world.

There are two possibilities: one, only certain kinds of information has consciousness. This might allow philosophical zombies to be constructed.

Or two, which I think is more likely than one, all information has consciousness. This means that we are in a panpsychic world. The world is thus teeming with consciousness.

Panpsychism is back again! Hooray!

when you realize Panpsychism isn't crazy

Have a panic attack wherever you are!