  But by no means has behaviorism disappeared. Robust elements of behaviorism survive in both behavior therapy and laboratory-based animal learning theory (of which more below). In the metaphysics of mind, too, behavioristic themes survive in the approach to mind known as Functionalism. Functionalism defines states of mind as states that play causal-functional roles in animals or systems in which they occur. Paul Churchland writes of Functionalism as follows: “The essential or defining feature of any type of mental states is the set of causal relations it bears to … bodily behavior” (1984, p. 36).  This functionalist notion is similar to the behaviorist idea that reference to behavior and to stimulus/response relations enters centrally and essentially into any account of what it means for a creature to behave or to be subject, in the scheme of analytical or logical behaviorism, to the attribution of mental states. 