  Behaviorism of one sort or another was an immensely popular research program or methodological commitment among students of behavior from about the third decade of the twentieth century through its middle decades, at least until the beginnings of the cognitive science revolution.  Cognitive science began to mature roughly from 1960 until 1985 (see Bechtel, Abrahamsen, and Graham, 1998, pp. 15–17). In addition to Ryle and Wittgenstein, philosophers with sympathies for behaviorism included Carnap (1932–33), Hempel (1949), and Quine (1960). Quine, for example, took a behaviorist approach to the study of language. Quine claimed that the notion of psychological or mental activity has no place in a scientific account of either the origins or the meaning of speech. To talk in a scientifically disciplined manner about the meaning of an utterance is to talk about stimuli for the utterance, its so-called “stimulus meaning”. Hempel (1949) claimed that “all psychological statements that are meaningful … are translatable into statements that do not involve psychological concepts,” but only concepts for physical behavior (p. 18).