David Chalmers on Consciousness
The second segment of the "Is There a Sixth Sense?" episode of Through the Wormhole (TTW) discusses consciousness and whether it is explainable in physical terms. The episode of TTW can be viewed here. Part 1 of my series of critiques is here.
The main reason this discussion of consciousness appears to be on the show is that it is intended to show that people can perceive something without being conscious of that perception. Thus, we might have a sixth sense without being aware of the operation of that sixth sense and we may need subtle third-person experiments to discover this sixth sense. In a way, this is a very odd claim to make. How could one have a sensory modality and not realize that one has it? And why should a discussion of the ineffability of conscious experience support this contention?
In fact, there are cases in which people have a 'sense' of which they are not aware. People, for example, have an ability to echolocate. Try walking (slowly) with your eyes closed down a quiet corridor on a hard floor. You might put your hand in front of your nose just to be safe. You'll find that you'll stop only a little distance from the wall. We're able to detect from the echoes of our footfalls that the wall is very near in front of us. It's not easy to describe the experience to people who haven't tried the experiment, but it does work. This is not really a new sense since it is just hearing, but one is using one's hearing in a way that one is not ordinarily accustomed to doing. Here's a rather striking example of the use of echolocation in humans.
So, we could show people that they have a 'sense' of which they were previously unaware, but it's not likely that only subtle, third-person experiments could bring it out. Senses are generally the sorts of things produce experiences that are in some way "present" to our consciousness, so the best way to show that there is a new 'sense' is to put people in circumstances in which they become aware of it. It is unlikely that there is a sense that one could not in principle become aware of from a first-person perspective although blindsight (noted in the previous installment) does provide such a case. Still, let's suppose that a sense of which we are completely unaware is theoretically possible.
However, you don’t need Chalmers to explain this possibility, and you don't need Chalmers to make sense of consciousness. Indeed, selecting Chalmers is more likely to make the concept of consciousness mysterious than it is to elucidate it. I'd be happy to hear about the problems Nagel, Jackson, Levine and even Chalmers have raised about consciousness, but you should at least (1) give the arguments for their Mysterian view of consciousness (that we cannot explain consciousness from a physical, reductionist or third-person perspective) instead of relying on mere descriptions of the position (and the apparent authority of Chalmers), and (2) present some alternatives or critiques.
Chalmers tells us that consciousness is a “fundamental building block” of the world on a par with the fundamental forces discovered by physics. Consciousness is like electromagnetism; electromagnetism was originally thought to be explainable in mechanistic terms, as a result of movements of particles with only mechanical properties, but was only later realized to require an entirely new force distinct from those already known to physics. One supposes such a view of consciousness is possible (epistemically--as far as we know, it is possibole) in the same way that there might be a god or an immaterial soul. We can conceive that the universe could be that way, but conceivability does not imply possibility. And arguing that the universe actually is that way requires a whole lot more argument.
Here's the argument in a nutshell against Chalmers's view. If consciousness is a fundamental force, then it can only be a coincidence that it occurs when but only when certain complex neural structures are in place. This coincidence appears to require some explanation, and on Chalmers's view, it is in principle impossible to give such an explanation in terms of other features of the universe (the other facts about complex neurological or functional features of entities). So, we either take on faith that there is this correlation, as Chalmers would have us do, or we suggest that there is some explanation for it.
Presumably Chalmers could say that simplicity is not a perfect guide to truth, and so his theory might be correct even if it introduces brute correlations. I don't see any way that Chalmers gains any explanatory insight by making his "fundamental building block" assumption, so it looks like simplicity provides a strong reason to reject his view.
A panpsychist could say that, in fact, there is no brute correlation between complex neural structures and consciousness but only that certain neural structures allow consciousness to be expressed or identified from the third-person perspective. Thus, anything might be conscious, but we are only capable of recognizing consciousness in those organisms with a particular sort of complex neural structure. This response would imply that consciousness plays no causal role in behavior (at least) since the complex neural structures appear to do all the causal/explanatory work. And if consciousness, on Chalmers's view, has no causal power, then we should reject his view. It's just wildly unlikely that consciousness doesn't do anything.
Don't get me started on the arguments for Chalmers's view.
So, Chalmers's view is only a bare epistemic possibility, not something that's reasonably supported by evidence. We cannot show that it is metaphysically impossible for consciousness not to be a fundamental building block of nature, but there is no reason to take this view seriously. Thus, talking only to Chalmers about consciousness is like asking Shaggy whether there's really a ghost pirate ship terrorizing the beach-goers. Maybe this time there really is a ghost, but you probably should talk to Fred, Daphne, and Velma first, and you definitely should put the burden on anyone who thinks there is no natural explanation (or explanation in known natural terms) for the phenomena in question. Relying on Chalmers's authority is far too flimsy.
Conclusion: Sixth sense fail.
This segment of the program could have been very interesting and informative, but it went for cheap titillation instead of education. Consciousness, whether mysterious or not, is not a sixth sense previously undiscovered by science. It's probably just a very complex physical phenomenon whose explanation we have yet to fathom. Also, Chalmers gets major demerits for his pretentious rock and roll posing.