History of physics and the Platonic legacy: a problem in Marburg Neo-Kantianism

In this article, I argue that the interpretation of Kant's a priori in Marburg neo-Kantianism involved a historiographical problem concerning the Platonic interpretation of the history of exact sciences. According to Hermann Cohen, the history of modern science supports the philosophical view initiated by Plato and revived by Kant that ‘the diversity of things has to be dissolved in differences of ideas’ and thus points to the “victory of idealism” over empiricism and materialism. I first examine how Cohen and Paul Natorp tried to confirm this epistemological thesis in their historical research on Plato and modern physics. Then I focus on Cassirer's work, which provides the most extensive realization of this historiographical programme and, I submit, clearly shows the problematic gap between the ‘Platonic’ epistemology of the Marburg school and the historical reality of physics from Galileo to the early twentieth century.