Suppose epiphenomenalism is true about qualia, so qualia are nonphysical properties that have no causal impact on anything. Let w0 be the actual world and let w1 be a world which is exactly like the actual world, except that (a) there are no qualia (so it’s a zombie world) and (b) instead of qualia, there are causally inefficacious nonphysical properties that have a logical structure isomorphic to the qualia of our world, and that occur in the corresponding places in the spatiotemporal and causal nexuses. Call these properties “epis”.
The following seems pretty obvious to me:
- In w1, nobody knows about the epis.
But the relationship of our beliefs about qualia to the qualia themselves seems to be exactly like the relationship of the denizens of w1 to the epis. In particular, neither are any of their beliefs caused by the obtaining of epis, nor are any of our beliefs caused by the obtaining of qualia, since both are epiphenomenal. So, plausibly:
- If in w1, nobody knows about the epis, then in w0, nobody knows about the qualia.
Conclusion:
- Nobody knows about the qualia.
But of course we do! So epiphenomenalism is false.
That’s an interesting thought experiment. The only issue I have with it is that I’m not sure how you are distinguishing between qualia and epis. You say how they are the same, but you don’t say how they are different. Maybe you just mean to say epis are definitely causally inert, but qualia only MIGHT be causally inert. Or maybe you mean to say epis are like qualia in every way except that there’s no first person subjectivity to epis. I’m not sure.
ReplyDeleteIf the lack of subjectivity is what distinguishes epis from qualia, then the fact that nobody in W1 knows about the epis doesn’t tell us anything about whether the people in W0 know about qualia, so I feel like there’s something I’m not understanding about your argument.
Maybe you mean to say the only way we COULD know about qualia or epis is if one or the other was causally efficacious. The only way that makes sense to me is to suppose that *we* are distinct from our qualia, or that our beliefs are distinct from qualia. Unless I’ve got some misunderstanding of what qualia are, isn’t the thought, “I’m in pain,” or “I’m thinking about chocolate,” an example of qualia? Can you distinguish beliefs from qualia? I thought beliefs (or at least the ones we’re currently thinking about) were examples of qualia.
If I come across as an amateur, it’s because I am. But I’m very interested in this subject.
I wanted to ask you one other thing if you don't mind. I've had a lot of conversations with people about epiphenomenalism and mental causation. I've used zombie thought experiments to try to illustrate why I think epiphenomenalism is a likely consequence of physicalism. The objection I most often hear is that it's a question-begging argument I'm making. The reason is because if it turns out that minds are the products of brain activity, or if they are the same thing as, then you cannot have the exact same brain activity in a different world without the corresponding mental activity. Zombie thought experiments are incoherent. Do you think that's a good argument against zombie thought experiments?
ReplyDeleteA belated Happy Easter, Professor Pruss. Christ is risen!
ReplyDeleteSam:
ReplyDelete1. I meant the epis to be irrelevant to consciousness.
2. As I think qualia are normally understood, the thought "I'm in pain" is not a quale. It is a thought about the occurrence of a quale. The quale is the feel of pain itself. An individual can probably host a quale without any beliefs (likely, a turtle in pain does not have any belief that it is in pain).
3. I don't think zombie thought experiments are compelling to everyone. Some have a strong intuition that there is nothing about the material arrangement that ensures consciousness. Others lack that intuition. Personally, what I find stronger are arguments that on computational theories of mind (which are the best alternative to dualism) it is too easy to get mind, as well as arguments that computation itself cannot be defined apart from a mind or a primitive teleology.
James:
He is risen indeed!