This paper is the introduction essay to an edited collection entitled "Law, Economics, and Evolutionary Theory", forthcoming with Edward Elgar. The volume brings together work by legal scholars, economists, historians and sociologists and aims at a critical investigation of the parallel and often competing theoretical architectures of legal and economic governance from an evolutionary perspective. By reconstructing discussions in law over the relationship between legal realism, law & society, and law & economics, and in economics over the merits and prospects of institutional and neo-institutional economics from an evolutionary perspective, the introduction argues that a theory of governance must today build on and incorporate the developments in both of these regulatory disciplines. Contributions from evolutionary theory and sociology, in particular in the important field of economic sociology, provide a fresh perspective on the particular dynamics of disciplinary development. Authors to the volume include Marc Amstutz, Amitai Aviram, Bruce Benson, Gralf-Peter Calliess, Fabio Carvalho, Paul David, Simon Deakin, Bart Du Laing, Martina Eckardt, Thráinn Eggertsson, Jörg Freiling, Wolfgang Kerber, Richard McAdams, Joel Mokyr, Eric Posner, Moritz Renner, Erich Schanze, Jan Smits and Mauro Zamboni.