… we cannot tell from form alone into which class a response falls. Fire may be (1) a mand to a firing squad, (2) a tact to a conflagration, (3) an intraverbal response to the stimulus Ready, aim …, or (4) an echoic or (5) textual response to appropriate verbal stimuli … In order to classify behavior effectively, we must know the circumstances under which it is emitted (p. 186)
