Publisher Summary This chapter describes various research, which demonstrate that the establishment of stimulus-reinforcer contingencies (i.e., Pavlovian conditioning) produces powerful effects on skeletomotor activities of the whole organism. Even though the animal's behavior does not affect unconditioned stimulus (US) delivery, the organism moves toward or away from environmental stimuli, depending on whether these stimuli are positively or negatively correlated with the reinforcer. Moreover, behavior directed at signals of impending reinforcement is surprisingly difficult to eliminate and frequently persist even if it actually prevents the delivery of a scheduled reinforcer. The fact that the experimental arrangements produce directed actions and yet fulfill most of the usual criteria for Pavlovian conditioning raises serious questions about the respondent-operant distinction. The results indicate that the learning of a relationship between a stimulus and reinforcer precedes and guides skeletal movements in various situations. The results of the research described in this chapter imply that the operant-respondent distinction is not very helpful and may be quite misleading, as all behavioral tasks involve potential interplay between stimulus→stimulus and response→stimulus relations, even if the experimenter does not explicitly arrange them.