Two days ago I presented an argument to the effect that if more than one qualia could be associated with a single internal state then it would be impossible to know which qualia we were experiencing. And part of this argument turned on the fact that the only way to defend knowledge of our own qualia given such an assumption would be to know the laws by which qualia operate, and that we could not rely on our knowledge of such laws because positing them presupposes that we can have knowledge of our qualia. Michael Pauen has presented a similar argument (Michael, P. (2006). Feeling Causes. Journal of consciousness studies, 13(1-2), 129-152) against the position that qualia are non-physical and epiphenomenal, also relying on the fact that we cannot know the laws by which qualia operate given such an assumption. Alexander Staudacher has written a response to this argument (Staudacher, A. (2006). Epistemological Challenges to Qualia-epiphenomenalism. Journal of consciousness studies, 13(1-2), 153-175) in which he claims that it is unsuccessful. And if Staudacher is right that may very well mean that my argument is flawed as well, since it is so similar to Pauen’s. However, I do not think that Staudacher’s response is successful, and so the argument against epiphenomenal qualia, and the possibility of more than one qualia being associated with a single internal state, is safe.
Staudacher raises three objections to Pauen’s argument. The first is that if we can’t have knowledge about epiphenomenal qualia then we can’t have knowledge about qualia under any theory. He claims that just as we can’t justify, according to Pauen, the proposed laws by which qualia operate then neither can we justify a claim that they are identical to certain functional properties, and takes this as a reductio ad absurdum of Pauen’s position. (Actually Staudacher presents analytical functionalism as the only way out, and says that if we can know the identification a priori then we can know the laws a priori. But obviously analytic functionalism is not the only way out, any theory which identifies qualia with something physical will do.) However this objection involves a false premise, that we must justify identity claims in the same way we justify laws. It should be obvious that this is not the case. For example, if it was claimed that Hesperus had a certain law-like effect on Phosphorous which explained why neither was seen at the same time we would require this law to be justified by observations of it in effect in other situations. But we don’t expect the claim that Hesperus is Phosphorous to be justified by observations of the identity relation (how can you even observe the identity relation?). An identify claim can only be disproved, either by making an observation in which identity is impossible (in this case seeing Hesperus and Phosphorous at the same time) or by demonstrating that such an identity would require the violation of some other known law (in this case possibly by requiring the planet to move too fast or in some other unusual manner in order to account for observations of both Hesperus and Phosphorous). So, epistemically, positing the existence of a law and positing an identification are significantly different. And, while we cannot justify positing laws for qualia without first being able to know what our own qualia are, we can justify positing an identification between our qualia and some part of our internal state, provided that we have never observed a qualia and the internal state it is supposed to be identical with “coming apart”, and that such an identification doesn’t contradict a theory about qualia with more empirical justification. Thus Staudacher’s first objection is not valid.
Staudacher’s second objection is that if qualia are simply to be identified with whatever fulfills a particular causal role within the brain then our knowledge of our qualia is not special or first-personal in any way. This is, again, supposed to be a reductio ad absurdum of the position that we can know about our qualia because they do have a causal effect. But it is easy to explain why our knowledge of our own qualia is special, even if qualia are physical. The difference between our knowledge of our own qualia, and say someone who is observing the operation of our brain, is the content of our beliefs about them. In our beliefs about our qualia we are intentionally directed at them, as is the party observing our brain. But the way we are intentionally directed at them is not the same. Both a blind man and a man without any sense of touch may be intentionally directed at the same tree, but they will not be intentionally directed at the tree in the same way. The blind man will be intentionally directed at it through his expectations of the way the tree feels, and the man without touch will be intentionally directed at it through his expectations about the way it looks. Similarly we are intentionally directed at our own qualia through the way they feel, the way they affect our consciousness (a kind of inner sense, if you will), while the external observer is directed at them only though their observations of the device they are measuring our brains with. So our knowledge of our own qualia will always be uniquely first personal, even if qualia are physical, because of the way we are related to them and come to know them.
Staudacher’s final objection is that the radical possibility that we may not have qualia need not affect whether we are justified in believing in them, just as we can’t justify believing that our reasoning isn’t defective, but nevertheless treat conclusions based on reason as justified. Of course these situations are not as similar as Staudacher would like us to believe that they are. The ability to reason is a precondition of being able to consider whether our beliefs are justified, and so we may just accept it as something we must accept without justification. But qualia are not a precondition of doing epistemology. In any case Pauen only needs to lean on the possibility that we do not in fact have qualia in order to demonstrate that if qualia are epiphenomenal then we have no evidence that they exist (by pointing out that things would be exactly the same were they gone). But the possibility of having inverted qualia, or radically different qualia, or qualia that are really identical to some physical process can equally serve as an alternative to the possibility of non-physical and epiphenomenal qualia for Pauen’s purposes. Thus we do not need to posit the possibility of absent qualia in order to demonstrate that we have no evidence for epiphenomenal qualia. And my version of the argument is especially safe against this objection, because all I need to posit is the possibility of qualia altered without having any causal effect, and that very possibility is what my argument is a reaction to. Staudacher’s objection is based on the premise that we can ignore alternatives that are motivated by skeptical considerations when reasoning about justification, and, while we might accept that, he is begging the question if he thinks we can rule out considering the possibility of physical qualia in our epistemic considerations for that reason.