 (Ibid., p. 212) Decades later, Simon used a similar terminology to distinct two meanings of "rationality", which have developed separately in economic and psychology.He defined substantive rationality, stemming from the concept of rationality within economics, as behavior that "is appropriate to the achievement of given goals within the limits imposed by given conditions and constraints".Procedural rationality, based in psychology, refers to behavior that "is the outcome of appropriate deliberation".