Previously I detailed one possible response to the knowledge argument against epiphenomenal qualia (and hence dualism in general), which claims that if qualia are epiphenomenal then we cannot in fact know that we have them, and thus that the theory undermines itself by denying that it is in fact justified. The responses I discuss today share a similar problem, they engage in epistemic question begging. Epistemic question begging is when the theory itself is the only justification for thinking that we have evidence in favor of the theory. In this context epistemic question begging involves invoking the very claims of the very theory in question about how qualia are connected to physical states, that we have qualia, or how qualia are related to each other, in order to justify our knowledge of qualia. But first let me give a few absurd examples that demonstrate why epistemic question begging is unacceptable. Suppose I claim that there are angels that tag along with all of us, and that these angels systematically interfere with our qualia, and that without such interference green would seem like red and vice versa. How can we know that these angels exist? Well green seems like green and not red, and that is evidence that the angels exist. Or suppose that there is a box, which we never touch or probe in any way, with a red light and a green light. Sometimes the green light is on, and sometimes the red light is on. Now I claim that there is a single oxygen atom in the box, and that when it is on the right the green light goes on, and when it is on the left the red light goes on. How do I know that is what the lights indicate? Well you see when the green light is on the oxygen atom is on the right, and from knowing such correlations I know that is what the lights indicate.
With such situations in mind let us turn to William S. Robinson’s defense of the compatibility of epiphenomenal qualia and knowledge about them (Robinson, W. (2006). Knowing Epiphenomena. Journal of consciousness studies, 13(1-2), 85-100). He claims that we can in fact know what our qualia are because “We would not normally report that we had an F qualitative event unless the brain events that cause an F qualitative event were occurring.” And that is true, according to Robinson, because we learn to use the words describing our qualia in circumstances where we actually have them. Hopefully this is obvious as an example of epistemic question begging. Robinson is assuming that the account of epiphenomenal qualia is correct, and that in normal circumstances we really do have the qualia that we are disposed to claim that we do. But we are in search of a justification for that account, and the belief that we are usually right about our qualia. So clearly it is absurd to invoke it in defense of the idea that we know our own qualia. (Or, to come at the circularity from another direction, we only suppose that we know that such a regular connection between qualia and our reports is because we think we know what our qualia are, and that this knowledge confirms the belief that our qualia and our reports are synchronized. Obviously then the existence of this connection, which pre-supposes we can know our own qualia, can’t justify the idea that we know our own qualia.)
Chalmers gives a similar defense of our knowledge of our own qualia (Chalmers, D.J. 2002c. The Content and Epistemology of Phenomenal Belief. In (Q. Smith & A. Jokic, eds) Consciousness: New Philosophical Essays. Oxford University Press). Chalmers supposes that the content of our phenomenal beliefs depend in part on the qualia that we do in fact have. Again, this is epistemic question begging, much like the case of Robinson, with the correlation between qualia and reports of those qualia replaced with a correlation between qualia and the content of phenomenal beliefs. And again the fact that the correlation exists presupposes that the theory about qualia is correct, and so it can’t be used to justify our knowledge about our qualia.
Now epistemic question begging doesn’t always defeat a theory, specifically when that theory is motivated as the best explanation of events. For example, maybe we could argue that our theory about the oxygen atom fits the red-green light behavior of the box extremely well, and so that we are justified in positing it as an explanation. But this cannot justify an epiphenomenal account of qualia, for two reasons. First is that the best explanation is an extrapolation of justified laws into a situation where we can’t directly observe them at work. We know how oxygen atoms work, so we could use those laws of oxygen atom behavior to show that the behavior of the box fits how the box would behave were it measuring the position of the oxygen atom. That is not how epiphenomenal qualia are motivated as an explanation, we have not observed epiphenomenal qualia in action (by definition) in other places and then used that knowledge to show that the way epiphenomenal qualia behave and are connected to physical events accounts perfectly for our experience. Secondly, we must be in a situation where we have knowledge about what needs explaining, such that our knowledge of it is independent of our theories about how it is to be explained. For example, in the case of the box we could know which light was on. Obviously in the case of the human mind qualia and experience are not what need explaining, in the sense that, while we would like to explain them, explaining them cannot justify our theory because a theory about them could very well claim that we are often mistaken about them. What needs explaining then is behavior. And if it really is impossible for qualia to be physical then eliminative materialism provides a better explanation of behavior than epiphenomenal qualia. Given this epistemic question begging is sufficient to reject a theory about qualia.
With respect to qualia the same point can be put in another way. The fact that we have privileged knowledge about our qualia is something that we accept as a basis for our theories. We use our knowledge about our own qualia (and experience in general) to determine how well a particular theory about consciousness explains our consciousness. Thus our knowledge of our own qualia must be more fundamental than our theories about consciousness, meaning that while we can use our knowledge about our own qualia to verify or refute a theory about consciousness we cannot use a theory about consciousness to explain how we know our own qualia. Our knowledge of our qualia must be independent of any regularities that we introduce especially to explain consciousness, and so qualia must participate in the normal causal order. If they don’t our theories about consciousness become epistemologically without foundation, and eliminative materialism becomes the better theory (partly because it is simpler), as we would no longer be able to refute eliminative materialism by appealing to our knowledge of our own consciousness; eliminative materialism would be free to explain that as simply a strongly held but false belief.