From the 1960s to the First World War, there was a trend to re-study and develop Kant's philosophy in Germany, and the so-called neo-Kantianism was formed, with the representative slogan "Return to Kant", among which the more influential factions were Marburg School and Freiburg School (or Southwest School). The founder of Marburg School is Herman Cohen (1842— 19 18), who developed Kant's transcendental idealism from the perspective of natural science methodology. Cohen abolished the dualism of sensibility and intellectuality in Kant's philosophy, and thought that space and time were not the innate form of sensibility as Kant said, but the construction mode of "pure thought". The so-called pure thought is his own innate principle system, which can be changed with the progress of science.

On the other hand, Cohen put forward ethical socialism, which is a moral ideal. The transcendental moral law requires that all social systems must become democratic systems and all individuals should become legislators in order to express their unified will and desire. This view has been appreciated by some people in the Second International. William Windelband (1848- 19 15) is the founder of Freiburg School, and he emphasized the humanities. He put forward a widely circulated but controversial view: natural science pursues the establishment of universal laws, so it can be called legislative (universal) knowledge; But historical science seeks to describe unique individual historical events, so it should be called individual knowledge.

Another representative of Fribourg School, Henry H. Richter (1863-1936), inherited this view of Vendel's class, and further proposed that the task of historical science or cultural science is to discover the universally accepted values in culture shown by specific historical events, because it is these cultural values or ideals that determine the historical significance of an event. These viewpoints of neo-Kantianism had a certain influence on natural science, social science and philosophy at that time.