The principle of transfer or stimulus induction supplies a fourth explanation of how a response to private stimuli may be maintained by public reinforcement. A response which is acquired and maintained in connection with public stimuli may be emitted, through induction, in response to private events. The transfer is not due to identical stimuli, . . . , but to coinciding properties. Thus, we describe internal states as “agitated,” “depressed,” “ebullient,” and so on, in a long list. Responses in this class are all metaphors (including special figures like metonomy). (p. 422)
