Foucault on the Marginal Revolution in Economics: Language and the Cartesian Legacy

Scholars have long debated the ‘revolutionary’ character of the ‘Marginal Revolution’ in economics, focusing on theoretical foundations, methodological devices, social context and political aspects. This article offers a new perspective by investigating ontological and epistemological conditions of that intellectual movement. This requires, in turn, a characterization of those conditions, for which purpose we will draw on Foucault's configurations of thought into ‘epistemes’ in The Order of Things. Although not mentioning those conditions, there have been few references in economics to Foucault's approach. They have mainly claimed that he neglected its importance because he did not see it as a ‘revolution’ in The Order of Things. It is argued here that he actually considered it a ‘revolution’ in The Archaeology of Knowledge. A revision of Foucault's account provides some ideas regarding deep philosophical conditions of the emergence of neoclassical theory and defies some usual interpretations of the circumstances that led to the mathematization of economics. The main conclusion is that its revolutionary character did not stem from a change of ontological beliefs, but—just as many historians of economics have defended—it was a methodological revolution. This study suggests a reinterpretation of that event, claiming that it resulted from a new conception of language and a crisis of Descartes's project of a mathematical unifying science. Going beyond that debate, these reflections proffer ideas that deserve an appraisal in economics.