to it.  On the one hand too much, and on the other too little, is regarded as the original possession of the understanding.  The question “What concepts are innate?” can be decided only by answering the further question, What are the concepts through which the faculty of judgment connects the representations obtained from experience?  These connective concepts, these formal instruments of synthesis are a priori.  The agreement of the two schools is still greater in regard to the relation of sense and understanding, notwithstanding the apparently sharp contrast between them.  The empiricist considers thought transformed, sublimated perception, while the rationalist sees in perception only confused and less distinct thought.  For the former concepts are faded images of sensations, for the latter sensations are concepts which have not yet become clear; the difference is scarcely greater than if the one should call ice frozen water, and the other should prefer to call water melted ice.  Both arrange intuition and thought in a single series, and derive the one from the other by enhancement or attenuation.  Both make the mistake of recognizing only a difference in degree where a difference in kind exists.  In such a case only an energetic dualism can afford help.  Sense and understanding are not one and the same cognitive power at different stages, but two heterogeneous faculties.  Sensation and thought are not different in degree, but in kind.  As Descartes began with the metaphysical dualism of extension and thought, so Kant begins with the noetical dualism of intuition and thought.

Much more serious, however, than any of the mistakes yet mentioned was a sin of omission of which the two schools were alike guilty, and the recognition and avoidance of which constituted in Kant’s own eyes the distinctive character of his philosophy and its principiant-advance beyond preceding systems.  The pre-Kantian thinker had proceeded to the discussion of knowledge without raising the question of the possibility of knowledge.  He had approached things in the full confidence that the human mind was capable of cognizing them, and with a naive trust in the power of reason to possess itself of the truth.  His trust was naive and ingenuous, because the idea that it could deceive him had never entered his mind.  Now no matter whether this belief in man’s capacity for knowledge and in the possibility of knowing things is justifiable or not, and no matter how far it may be justifiable, it was in any case untested; so that when the skeptic approached with his objections the dogmatist was defenseless.  All previous philosophy, so far as it had not been skeptical, had been, according to Kant’s expression, dogmatic; that is, it had held as an article of faith, and without precedent inquiry, that we possess the power of cognizing objects.  It had not asked how this is possible; it had not even asked what knowledge is, what may and must be demanded of it, and by what means our reason is