I. Haeckel and His Opponents

A philosophy that understands itself, and turns its attention to an unprejudiced contemplation of the human spirit, thus yields a further proof of the correctness of the monistic world-conception. It is, however, quite incompatible with a dualistic natural science. (The further development and detailed proof of a monistic philosophy, the basic ideas of which I can only indicate here, I have given in my = The Philosophy of Freedom, Berlin, 1894, Verlag Emil Felber.)