In his 1948 address to the Division of Theoretical-Experimental Psychology of the American Psychological Association, Kenneth W. Spence discussed six distinctions between cognitive and stimulus-response (S-R) theories of learning. In this article I first review these six distinctions, and then focus on two of them in the context of my own research. This research concerns the specification of stimulus-stimulus associations in associative learning, and the characterization of neural systems underlying those associations. In the course of describing Spence's views and my research, I hope to communicate some of the richness of Spence's S-R psychology, and its currency within modern scientific analyses of behavior.