Identity versus determinism: Émile Meyerson׳s neo-Kantian interpretation of the quantum theory

• Meyerson offers a unique neo-Kantian interpretation of quantum physics.
• His interpretation leads him to alter some of his central philosophical views.
• His discussion of positivism shows its influence on debates about quantum physics.
• I evaluate Meyerson׳s interpretation, comparing and contrasting it with other neo-Kantian approaches.

Despite the praise his writing garnered during his lifetime, e.g., from readers such as Einstein and de Broglie, Émile Meyerson has been largely forgotten. The rich tradition of French épistémologie has recently been taken up in some Anglo-American scholarship, but Meyerson—who popularized the term épistémologie through his historical method of analyzing science, and criticized positivism long before Quine and Kuhn—remains overlooked. If Meyerson is remembered at all, it is as a historian of classical science. This paper attempts to rectify both states of affairs by explicating one of Meyerson׳s last and untranslated works, Réel et déterminisme dans la théorie quantique, an opuscule on quantum physics.I provide an overview of Meyerson׳s philosophy, his critique of Max Planck׳s interpretation of quantum physics, and then outline and evaluate Meyerson׳s neo-Kantian alternative. I then compare and contrast this interpretation with Cassirer׳s neo-Kantian program. Finally I show that, while Meyerson believes the revolutionary new physics requires "profoundly" modifying our conception of reality, ultimately, he thinks, it secures the legitimacy of his thesis: that science seeks explanations in the form of what he calls "identification." I hope my research will enable a more general and systematic engagement with Meyerson׳s work, especially with a view to assessing its viability as a philosophical method today.