[Historic and functional biology: the inadequacy of a system theory of evolution]

In the first half of the 20th century neo-Kantianism in a broad sense proved itself the main conceptual and methodological background of the central European biology. As such it contributed much to the victory on the typological, idealistic-morphological and psycho-vitalistic interpretations of life. On the other hand it could not give tools to the biologists for working out a strictly darwinian evolution theory. Kant's theory of organism was conceived without evolution as a theory of the internal functionality of the organism. There was only some 'play' with the evolutionary differentiation of the species. Since then the disputes around the work of August Weismann, a synthetical evolution theory which is now behind time, arose. This theory developed from coinciding claims, elaborated by geneticists, mathematicians, and by biologists studying development, natural history and systematics. This was done under a strong influence of marxist ideas. Through the interweaving of such different approaches it was possible for this evolutionary synthesis to influence successfully the development of evolution research during more than 40 years. Philosophically speaking modern evolution theory means therefore an aversion, even a positive abolition of Kantian positions. A number of biologists however--as L. von Bertalanffy--refused to adhere to a misinterpreted Kantian methodology and oriented themselves to an approach via system theory, which obtained a place in evolution research. In fact this is a Kantian approach as well. They only repeated the Kantian dilemma of the evolution which can also be found in Lamarck and Hegel. The system theory of the functionality of the organism never reaches to the level of the evolving species, but remains always on the level of epigenetic thinking, because of its philosophical origin. This paper points out the consequences of this still current dilemma. At the same time an all-enclosing reflection on the methodological, epistemological and the important historical questions of evolutionary biology in its scientific context is recommended.