Current theories of organizational learning tend to concentrate on the mental states of organization members. Knowledge management is a good example in case. In this article a number of objections are raised against this emphasis on mental variables, elaborated in a critical analysis of the concept of knowledge management. As an alternative, a behavioral theory of organizational learning is presented, based on the work of Bateson, Weick and Skinner. Central concepts in this theory are proto-learning and deutero-learning, which are outlined in general terms and applied to organization and management.