Saturday, March 12, 2005

The Importance of Mental Names

In a comment to my last post, Clark alerted me to an interesting post at Certain Doubts. In the post is an example that is supposed to bear on whether we can, under some circumstances, be mistaken about the content of our own minds. Here is the example (quoted from the post):
You go to the doctor complaining of an itch. He listens to your complaint, observes the location of the itch, writes down how the problem started, and the details about physical symptoms including duration and intensity of the experience. Then he tells you that he thinks he knows what the problem is. He tells you that it’s not really an itch, but a pain. People have confused these two in the past, but we now have a well-confirmed theory that distinguishes the two in a slightly different way than “the folk” do. The theory has led to two technologies. One is a machine for distinguishing the two underlying states, and the other is medicine for treating the two conditions. Your doctor tells you that one of the medicines will solve the problem if you’re experiencing a pain, but not the itch; and the other medicine will have the alternative results. You insist that you’re experiencing an itch, but he uses the machine and shows you the results: you’re in pain, it says. If you still insist, he’ll give you the itch medicine. You do, and he does; you return two weeks later, still suffering, and ask for the pain medicine. You take it and get well. So you say, “I guess I was wrong. It was a pain, not an itch, after all!”
Clark thinks that the problem in this example has to do with names, and I think he's right. In fact, I think this example presents a very nice analog to Barbara Malt's "water" experiment that I described in the previous post. In that experiment, participants' beliefs about the H2O content of various liquids were not correlated with their use of the name "water" to describe the liquids. Malt uses this result to argue, effectively I think, that people are not using names to refer to essences. In the pain example, the patient refers to "pain" that is not consistent with what the doctor believes to be its essence, namely the presence of certain physical states (presumably composed of patterns of neural firings). Obviously there's an important difference between the two examples: in the Malt experiments, participants' uses of a name were inconsistent with their own beliefs about the essential content of the referents, while in the pain example, the patient's use of a name is inconsistent with the doctor's belief about the essential content of the referent. Also, to even consider the possibility that the patient is mistaken about her mental states, we have to accept a reductionist theory of mental content, which is more difficult than accepting some form of reductionism about the nature of water. Differences aside, though, if the Malt experiment shows that people do not use names to refer to essences, can we conclude from the example that the patient is using the name incorrectly, and is thus mistaken about the content of her mental states? It seems reasonable to conclude that the name "pain" is not co-extensive with the physical essence of pain, just as the name "water" is not co-extensive with H2O. In that case, the example doesn't show that the patient is making a mistake. In fact, until we actually determine the meaning of "pain," as used by the patient, the example doesn't really tell us anything.

In Malt's "water" experiment, it appears that there are two senses (or intensions) for "water," one which is scientific (water = H2O), and one which is broader, and used in everyday speech. In fact, to describe Malt's experiment, you have to use both senses. Participants' beliefs about the water (in the scientific sense) content of a liquid are not correlated with whether participant call that liquid water (in the everyday sense). I suspect that the same can be said of the "pain" example. The scientific sense of "pain" involves a theory about the physical states that cause pain, while the everyday sense refers to a range of qualitative experiences. That range of qualitative experiences may not be co-extensive with the range of experiences caused by the physical states scientifically referred to as pain.

It could turn out that there really is a one-to-one mapping between brain states and qualitative experiences, and thus that the patient really is mistaken about the content of her mental state. But what would that mean (and why do I feel like J.L. Austin when I ask that?)? How could I possibly have a qualitative experience that mistakes itself? Perhaps a lapse of memory, which causes the patient to believe that the content of her mental state is more similar to past experiences of pain, when in fact it is more similar to past experiences of itching, might cause this. I'd be willing to bet that, given the fuzzy nature of categories, and the ambiguity of some experiences, this is possible. The patient's qualitative experience might be on the experiential border shared by itching and pain, and thus difficult to categorize. However, if it really does feel like pain, I see no reason to say that the patient should be considered wrong in calling it pain. The doctor may need to think of it as pain, in the scientific sense, in order to treat it effectively, but the patient, in order to classify her experience, should label it in a way that is most consistent with her own experience. How would doing otherwise help her?