Mind, Matter, and Nature

3. The Case against Dualism: The Problem of Mind-Body Interaction

58 Chapter 3 The Case against Dualism The Problem of Mind-Body Interaction In our last chapter we considered several valid (if their premises are true, then their conclusion likewise must be true) arguments for dualism, but their soundness (whether in addition to being valid the arguments have true premises) is something about which there can be legitimate disagreement. We concluded that even if these arguments do not rise to the standard of complete philosophical demonstration, it is not unreasonable for a dualist to justify her position on such grounds. Along the way we considered objections to some of the premises of the dualists’ arguments that we might expect materialists to introduce, which we found to have significant force, even if not themselves decisive. Notice, however, to refute (or call into question) the argument for a position is not the same thing as to prove that such a position is false. For example, I might give you good reasons to 59 The Case against Dualism doubt somebody’s argument in support of the existence of the Easter Bunny, but that is not to say that I have necessarily given you good reasons to conclude that there is no such being.1 In this chapter, we will turn our attention not just to objections to arguments in support of dualism, but to attempts to prove that dualism is false (or at least that it is unreasonable to accept such a doctrine). If these arguments against dualism are successful, then we would have good reason to reject dualism, even in light of the arguments we discussed in the previous chapter. As we shall see, the attempt to show that dualism is false (or at least not something we can reasonably believe) is the first step in the materialist’s overall project. After putatively showing the absurdity of dualism, the materialist typically attempts to give an account of psychological states in entirely physical terms (or to reject the reality of psychological states entirely). That is, materialists try to show how sensations and thoughts could turn out to be material objects, or that there really are no such states, despite the appearance otherwise. If thoughts and sensations could plausibly be claimed to be material objects or merely illusions, then our certainty in the key premises of the various arguments for dualism should be seriously shaken. Successfully casting doubt on these premises, coupled with a successful criticism of dualism , would give the materialist a particularly strong case for his position. Thus, materialists employ a two-phase strategy in their rejection of dualism: (a) They point to the problem of mind-body interaction and other considerations that they suppose to give us good reasons to think dualism is false, even absurd; and (b) they offer various theories of mind that treat thoughts and sensations as either nonexistent or physical states, while attempting to show that such an account can still make sense of our commonsense notions about minds. In this chapter we will discuss in some de1 . Remember that we are assuming that the dualist and materialist share the burden of proof, though the burden of proof in the debate over the Easter Bunny would presumably fall squarely on the pro-bunny side. 60 The Case against Dualism tail the prospects for the first phase of the materialist strategy. The second phase will be our concern in the following chapter. Intelligibility One of the most compelling facts about psychological states is their effectiveness; that is, they seem to make a difference for our behavior. Brendan winced because of the pain caused by scraping his knee. Will did his homework because he wants desert. Martha said, “Seven!” because she thought that was the right answer. In all of these cases, each of which seems perfectly plausible, a sensation or thought causes a behavior involving a physical motion in the person’s body, most directly in his or her brain. Moreover, it is equally obvious that our bodily states have an effect on what psychological states we might be in; we feel pains as a result of injury to our bodies, and our actions (as both moral and intellectual agents) are often prompted by an encounter with some physical object. One of our primary experiences of ourselves is as agents speaking or acting because of some prior psychological state, and subsequently it is hard for us to take at all seriously even the suggestion that our...