solution of those problems which are of greatest interest to the human consciousness, he opens the door to every kind of fantastic and arbitrary speculation, undermining at the same time the most stable foundations of moral life. His physiological interpretation of the a priori of Kant deprives science of all essential and universal value, narrowing it down to a sceptical subjectivity, and merely sets the problem without solving it. Our physiological constitution is undoubtedly a part of the world of experience, and therefore the a priori conditions of its possibility demand investigation. Lange is not aware that he is moving in a vicious circle: the basis of mechanical explanation is to be found in our organic structure, but this structure in its turn demands a mechanical explanation. It is impossible to conceive of the physiological organism without making use of those intuitive forms and categories which are supposed to be deduced therefrom, and it therefore presumes the laws of thought and the activity of the knowing subject. With Lange begins that confusion between epistemological, psychological, and physiological problems which serves later as the basis of empirio-criticism and pragmatism. Thus, then, the doubt as to the reality of the thing in itself to which it gives expression is but the first step to phenomenalism which calls upon psychology and physiology to explain the illusion of the two opposing terms. On the other hand, if intelligence be unable to discover the sources of our organisation which are also the sources of thought, and if feeling and poetic insight succeed where intelligence failed, is not creative intuition anterior and superior to the intellect? How else, Bergson would ask, can we reach the inmost heart of things? We have seen that the philosophical system of Lange is vitiated by his incurable habit of begging the question; it is nevertheless of great historic value in as much as it strives to overcome sordid materialism, but unfortunately he fails to free himself wholly from its toils, and to place intellectual knowledge on a sure foundation.
