Adam Smith famously stated that “from the cradle to the grave” humans strive to improve their situation. However, taking human “opportunism” seriously, the original Hobbesian rational choice model re-emerges, rendering Smith’s own account of the legal order – including his policy proposals for improving it – implausible. The Hobbesian model of case-by-case future-directed opportunity taking behavior in view of the causal consequences of each choice act taken separately has far reaching implications: rationality and maximization may clash, the so-called Folk theorem of game theory seizes to be operative in the ideal world of fully rational beings, and the creation of “law and social order” among ideally rational actors becomes infeasible.

Taking “Hobbes to heart” the presentation shall show: First, British Moralists directly following Hobbes – and, late in his life, even Hobbes himself – already rejected the view that social interaction and order could be explained solely in rational choice terms. Second, the early philosophical criticisms can be reformulated more precisely and validated by borrowing certain concepts of “equilibrium refinement” from modern game theory. Third, Herbert Hart’s account of social and legal institutions explains their existence in terms of the rule-following behavior of individuals who can do both, follow rules and take opportunities. Fourth, since game theory shows that regularities in overt institutionalized behavior cannot be fully explained in terms of “identical responses to regularly repeated sufficiently similar choice situations” we should conclude that collective commitments to rules cannot be explained without introducing some intrinsically motivated (“Wittgensteinian”) rule following of individuals. Fifth, it deserves to be emphasized that the impossibility of reducing full-fledged social institutions to opportunity taking rational choice behavior does not rule out the presence of opportunity taking behavior altogether.