Paul Natorp was born in Düsseldorf and died in Marburg. Along with Hermann Cohen, he is known as one of the founders of the Marburg School of Neo-Kantianism. He studied history, philology, mathematics, and philosophy in Berlin, Bonn, and Strassburg. After completing his doctorate in history at the University of Strassburg in 1876, he went to Marburg where Cohen was working on the restoration of Kant's critical philosophy. In 1881 Natorp obtained his postdoctoral qualification with a thesis on the prehistory of criticism titled Descartes' Erkenntnistheorie (Descartes's theory of knowledge). He became an associate professor at the University of Marburg in 1885 and eventually a full professor of philosophy and pedagogy. In spite of being offered several chairs at other universities, Natorp remained in Marburg throughout his lifetime.

Despite their close relationship, Natorp cannot be seen as a genuine follower of Cohen, especially because of the...