Understanding has hitherto been in error about itself and was, therefore, inadequately equipped for the task of giving a true account of its relatives, of the phenomena of nature and life. Nevertheless it has acquired training in the course of culture and has progressively accomplished better things. Its errors have never been valueless, and its truths will never be sufficient. That this is so, is not due to the defective condition of our intelligence, but to the inexhaustibleness of being, the indescribable wealth of nature. The self-conscious, philosophically trained understanding and intelligence has now the means of knowing that the accuracy of all investigation is limited, that for this reason all its future results will be affected by error. But a science which is backed up by such an enlightened understanding, is reconciled to its limitations and transforms them into a hall of glory. Self-conscious limitation is aware of its partnership in the absolute perfection of the universe. The self-conscious intellect improved by the positive product of philosophy knows that it can understand, describe, the whole world in a natural, sensible way. There is nothing that can resist it. But in the sense of a transcendental metaphysics, our understanding is not worthy of that name. In return, this metaphysics is pure vagary in the eyes of critical reason. Taking its departure from fantastical ideals, from contradictions, especially between being and not being, metaphysics has gradually transformed itself in the course of civilization and become philosophy, which in its turn has progressed step by step the same as all other science. Philosophy was at first impelled by the nebulous desire for universal world wisdom and has finally assumed the form of a lucid special investigation of the theory of understanding. This theory is part, and the most essential part at that, of psychology or the science of the soul. Modern psychologists have at least divined, if not recognized, that the human soul is not a metaphysical thing, but a phenomenon. Like Professor Haeckel, they also complain about the dead classification in their specialty. The human soul is presented to them as a multitude of _faculties_. There is the faculty of understanding, of feeling, of perceiving, etc., without number and end. But how is life infused into them? Where is the consistent connection?