Preface to the 1923 Edition

Against this, the objections might be raised that in such a treatment the content of the book would lose its unity. I am not of that opinion. An historical account will become the more faithful the more the phenomena are allowed to speak for themselves. It cannot be the task of an historical presentation to fight materialism or to distort it into a caricature, for within its limits it is justified. It is right to represent materialistically those processes of the world that have a material cause. We only go astray when we do not arrive at the insight that comes when, in pursuing the material processes, we are finally led to the conception of the spirit. To maintain that the brain is not a necessary condition of our thinking insofar as it is related to sense perception is an error. It is also an error to assume that the spirit is not the creator of the brain through which it reveals itself in the physical world through the production and formation of thought.