Functionalism and Eliminative Materialism – Paul M. Churchland
In this selection, Churchland discusses two materialist alternatives to identity theory. First, he discusses functionalism, according to which the most important feature of mental states is a set of causal relations among “(1) environmental effects on the body, (2) other types of mental sates, and (3) bodily behavior.” Churchland uses the mental state of pain to illustrate his claims. Pain usually results from bodily trauma, causes other mental states (e.g., distress), and influences behavior (e.g., working to reduce or avoid the pain, wincing). According to functionalism, any mental state the fits that role (resulting from the same thing and having the same effects) just is pain. Thus, any number of differently composed beings could have pain, not just those with physiology closely resembling ours. Churchland notes that, at the time of his writing, functionalism was the most widely accepted theory among philosophers of mind. He explains why this is so, citing several advantages that the theory holds over behaviorism and the identity theory. Functionalism, though, is not without its flaws, and Churchland discusses several of these, as well as how the functionalist might try to respond.
Secondly, Churchland discusses eliminative materialism. Eliminative materialists doubt that our common-sense understanding of psychological concepts will match neatly with underlying physiological mechanisms. That is, a neuroscientific account of mental life may not mesh well with the concepts we use to describe our mental life in other contexts. To illustrate this point Churchland discusses a number of historical examples of concepts that were eliminated by advancing science. For example, people used to think that there existed a substance called “phlogiston” in woods and metals; they believed that wood burning or metal rusting was just phlogiston being released into the air. However, better science revealed that burning and rusting were the result of wood and metal gaining oxygen, not losing phlogiston. Thinking that phlogiston existed and could be explained was a mistake; it was therefore eliminated from our ontology. Eliminative materialists think that the same is true of concepts like belief, pain, sadness, and so forth. As we better understand neuroscience, we can eliminate those concepts in favor of concepts that map physiology directly. As he did with functionalism, Churchland concludes his discussion of eliminative materialism by noting considerations that weigh in favor and against it.