This chapter outlines Elinor Ostroms inter-disciplinary perspective, which links social and natural sciences. Ostroms broad methodological approach is discussed and the Institutional Analysis and Development (IAD) framework is introduced. The theoretical framework of IAD was based upon game theory. Game theorists have generally assumed that participants in the game would engage in backward induction that would help the sub-optimal Nash equilibrium. Methodological individualism was strongly linked to the idea of personal freedom and political autonomy but via institutions like RAND Corporation might also, paradoxically or not, be associated with militarism and imperialist domination. Some of the practical research methods used by Ostrom including case studies, RAND Corporation, experiments, agent based models and satellite surveys, are described. John Searle, best known for his book Speech Acts (1969), developed a philosophy of language, drawing upon a tradition of pragmatism and the work of Austin and Wittgenstein.