Recently, the study of biological function has been reaccepted as a legitimate focus of research in the field of animal learning. This "new" functionalism suffuses 2 distinct perspectives with which researchers approach the study of Pavlovian conditioning. Those who adopt the ecological perspective explore the role of conditioning within functional, naturally occurring categories of behavior, for example, intraspecific defense, reproduction, or food recognition. From this perspective, the central question is, In what ways does conditioning contribute to animals' ability to survive and reproduce? For those researchers who explore the cause rather than the function of conditioning, the central question is, How, and under what circumstances, does conditioning occur? Although, historically, those who studied causal mechanisms eschewed functional considerations, close examination of the new cognitive perspective reveals decidedly functional themes. A brief review of research originating in each of these 2 perspectives demonstrates the ways in which they increasingly are finding common ground in a "new" study of function.