Why zombies are inconceivable (short version)

Consciousness does work.  My being consciously aware of various things motivates me to react in various ways, to do things in response.  The zombie scenario claims that consciousness has been removed, and everything else left the same, with "everything else" including the work that consciousness does getting done.  But that's impossible; if consciousness is removed, what it does won't get done unless something else does it instead (and the zombie scenario is certainly not supposed to be adding any substitutes).

To put it another way, if in a physical duplicate world the work consciousness does is still getting done, something physical must be doing the work in that world.  But if it's a physical duplicate world, whatever it is that is doing the work in that world is also present in this world.  But in this world consciousness is doing the work.  So whatever that physical thing that's doing the work is must, after all, just be consciousness.

This didn't end up being as short as I expected.  Still shorter than the last two posts on the topic, I suppose.

Comments

[Richard]

"My being consciously aware of various things motivates me to react in various ways, to do things in response."

That's not a conceptual truth. It's conceivable that all the physical behaviours we actually exhibit are not caused by phenomenal consciousness at all. You can't rule out the zombie world a priori.

At most, yours is an argument for the metaphysical impossibility, not the inconceivability, of zombies. But it rests on the controversial premises that (i) consciousness is causally efficacious, and (ii) there cannot be causal overdetermination, i.e. if physical event P suffices for outcome E, there cannot be a distinct mental event M which actually causes E. Zombiephiles will thus reject one or both of these premises.

[Aaron Boyden]

I don't see how it's not a conceptual truth that consciousness is causally efficacious. It seems to me to be part of what I mean by consciousness that it's this state that does certain things.

I confess that rampant over-determination strikes me as such a desperate move that it had not occurred to me to try to address it. I suppose it's good to have topics for future posts, though.

[Richard]

"It seems to me to be part of what I mean by consciousness that it's this state that does certain things."

Hence my worry in the earlier post that you were changing the subject, or at least that we are talking past each other. What I mean by 'phenomenal consciousness' is simply the quality of what it feels like to be in a certain state. Whether such 'raw feels' have any further effect is a secondary question, and certainly no part of the essential definition of the term. But there's no point squabbling over terms. So long as you allow that my concept is coherent and all that, we may dub it 'conscious*', and proceed to rewrite the argument against materialism in those terms.

[Aaron Boyden]

You don't seem to understand. I'm saying that it seems to me that what it feels like is what motivates me to act in certain ways, and to have certain other thoughts, etc. That very thing, the feeling, by being the way it is, has causal powers. Only a different feeling could have different causal powers; in order for something to be that feeling, it'd have to be the feeling that makes me want to do certain things, that leads to other thoughts, etc. I avoid painful things because of what pain feels like; something I didn't want to avoid couldn't feel like pain, because I want to avoid anything that feels like pain. In other words, I don't think your concept is coherent and all that, since you seem to be trying to distinguish something from itself, and nothing is distinct from itself.

[Richard]

Oh right. I actually explored that idea a bit in this post. I'm not entirely sure what to make of it (cf. pain asymbolia, a condition wherein people report feeling the raw feel of pain without being particularly bothered by it. And that's an actual case. When we shift to the merely possible, why couldn't someone experience epiphenomenal pain, which has no other effect at all? It's at least not obvious why this should be inconceivable).

But the feel of a mental state and its functional role are surely distinct features of it, even if you theorize that the latter is necessary for the former. (And it doesn't follow that the latter is *sufficient* for the former, as the materialist requires.) Talk of qualia is not talk of functional roles; epiphenomenalists are not blatantly contradicting themselves.

[Aaron Boyden]

No, I think epiphenomenalists are contradicting themselves. I don't know if it's blatant; that seems to be a subjective judgment.

I have, of course, oversimplified the case of pain. There can be confounding factors, and likely what it is to be pain is not wholly settled in certain marginal cases. While I think it may not be as easy to construct a case as Lewis thought (and so that in particular details his case failed), I do think that there can be what Lewis called mad pain. I don't think it's a problem for materialism, though, any more than Lewis did in providing his materialist account of mad pain (in "Mad Pain and Martian Pain.") It just shows that the materialist account needs to be a bit more complicated to respect all the details of a complicated phenomenon.

I wonder if that's part of the intuition that motivates opposition to any form of materialist analysis of qualia. Qualia seem to be simple, and any materialist analysis with any plausibility is going to be very complex. However, intuitive judgments of simplicity are extremely suspect, so while this may be a motivation for resistance to materialism, it isn't much of an objection to materialism.