This chapter demonstrates that an extreme form of positivism, the purely descriptive approach derived from Bridgman and Mach rather than the logical positivism of the Vienna Circle which, through its development of logical empiricism, became more accommodating to the epistemological assumptions of even interpretivist consumer researchers, has much to offer a genuinely pluralistic consumer research. The chapter describes some depth the ontology and methodology of radical behaviorism, and its ultimate reliance upon interpretive methods in order to give an account of complex human behavior. Four classes of consumer behavior identified by the model are analyzed using this interpretive method: Accomplishment, Pleasure, Accumulation, and Maintenance. The chapter evaluates this approach to consumer and marketing research. It argues that even radical behaviorism, founded upon an extreme positivism, cannot sustain this naturalistic position in the treatment of complex social experience in human affairs, notably in the economic psychology of purchase and consumption.