AbstractThe [ethogenic] analysis of human social behaviour proposed by Harré and Secord is based on the idea of man as a freely choosing purposeful agent, contrasted with the mechanistic, or deterministic, conception of man which is the basis of most traditional research and theory in social psychology.The idea that a person's social behaviour is governed by social rules is central in the ethogenic scheme. But the same idea is also implicit in much traditional research and theory. A consideration of the concept of social rule in the study of social behaviour helps to clarify the relation in which ethogenics stands to traditional social psychology and highlights a fundamental difference between them in their respective fields of enquiry. Harré and Secord's claim that the ethogenic paradigm should replace traditional models is misplaced because the two approaches are demonstrably compatible. Indeed, the necessity of a causal mechanistic account can actually be derived from certain assumptions of the ethogenic paradigm itself.It is shown that important headway may be made in social psychology, particularly in relation to the study of physical and mental illness, by acknowledging the compatibility of the two approache