 7. There is one final common feature of Neo-Kantian philosophers that should not be overlooked: the Neo-Kantians were great historians of philosophy. It’s not surprising that the Neo-Kantians wrote extensively on Kant, producing commentaries (e.g., Cohen 1885; Cassirer 1918) and critical editions of his writing. But the Neo-Kantians also wrote extensively on other philosophers, ancient and modern, and on the history of science and mathematics (e.g., Windelband 1891; Cassirer 1906, 1907a). These historical works were not thought of as side projects, but as essential aspects of their philosophy. Neo-Kantians did not sharply distinguish history of philosophy from philosophy (see Introduction to Windelband 1891; §I of the 1902 version of Cohen 1898).