Darwinian evolutionary theory denied that the history of living beings followed any conscious plan or definite aim. Evolutionary theorists of social development like Friedrich von Hayek also insist that rational calculation has a much more limited role in social life than usually assumed. Institutions and extended orders of social life evolved through the innumerable fumbling efforts of individuals who did not know what they were doing. Thomas Schelling, David Lewis, and Edna Ullmann-Margalit have, however, shown that rational choice theory can offer a valuable tool for analysing even the most eminent field of evolutionary social theory, the emergence of conventions and norms. In game theoretical terms, conventions solve a coordination problem in situtations with multiple equilibria when actors have to find the same equlibrium. Cristina Bicchieri later argued that the knowledge of the game being played and the self-evident principles of rationality were not sufficient to guarantee that an equilibrium would be attained. In the case of the emergence of norms, game theoretical analysis has to be complemented by evolutionary explanation. Brian Skyrms also emphasizes the superiority of dynamical models of evolution over the models of rational calculation in the explanation of large scale social processes. But neither Bicchieri nor Skyrms want to replace rational choice analysis by an evolutionary approach, they rather combine them. Skyrms calls his approach evolutionary game theory.