Hermann Cohen and His Idea of the Logic of Pure Knowledge

Hermann Cohen, as it is well known, criticised the Kantian notion of the thing-in-itself. And before him the Kantian thing-in-itself was criticised by Fichte and other German idealists. Probably for this reason, Hermann Cohen is sometimes regarded as a person who said things similar to Fichte. This gives a completely wrong perspective, making it impossible to understand the philosopher's ideas. The basis for his critique of the Kantian thing-in-itself is quite different from the motives, determining the criticism of Kant in the classical German Idealism. Such interpretation does not allow to see close connection of Cohen's theoretical philosophy with revolution in physics which took place at the turn of the nineteenth and twentieth centuries. The article explains how Cohen's demand that pure thinking must form its own content is connected with transformations taking place in physics and mathematics, and the peculiarity of Cohen's understanding of idealism is demonstrated: for him, correct idealism must realize that autonomous, free thinking should work seriously with sense data. The closeness of Cohen's ideas to the postpositivist thesis of the theory-ladenness of observation is explained. For Cohen, serious work with sense data is opposite to uncritical acceptance of them as given. The origin of scientific thinking is thinking itself. It responds to the challenge of sensory material by creating its own constructs. Mathematized natural science becomes for Cohen both an example and a confirmation of this thesis. For him, what is real is what is described in the language of mathematical analysis, i.e. continuous processes, in spite of the fact that any data are discrete. It is shown that the source of Cohen's assertions on this issue is in Kant's Critique of Pure Reason, namely in the doctrine of the Principles of pure natural science and, more specifically, in the Anticipations of Perception. Cohen's conviction of the constructive character of the theories of mathematized natural science is confirmed in the article by references to the authority of A. Einstein.