Natorp, Cassirer and the Influence of Relativity Theory on Neo-Kantian Philosophy

In this paper, I will survey the “received view” of the interpretation of relativity theory in Natorp and Cassirer. Neo-Kantian and non-neo-Kantian scholars (such as Hentschel or Ferrari) usually distinguish Natorp’s reading from Cassirer’s by virtue of “immunising” and “revising” strategies. “Immunisation” consists of a strict defence of Kantian philosophy, while “revision” pertains to the modification of Kantianism depending on relativity theory. In this respect, I will suggest some arguments that will put things in perspective. In particular, I will show that Natorp’s interpretation is justified considering the state of physical research in 1910. By the same token, I will highlight where Cassirer leverages immunising strategies. However, I will demonstrate that, in contrast to Natorp, the influence of general relativity (GR) is pivotal to Cassirer and it does have an impact on his whole epistemology (and philosophy), implying a highly radical reform of pure intuition in light of general covariance. I will also add that Cassirer may have a bearing on Einstein as to the possibility of reconsidering his former censure of Kantian philosophy.