%PART II.  FROM KANT TO THE PRESENT TIME.%

CHAPTER IX.

KANT.

The suit between empiricism and rationalism had continued for centuries, but still awaited final decision.  Are all our ideas the result of experience, or are they (wholly or in part) an original possession of the mind?  Are they received from without (by perception), or produced from within (by self-activity)?  Is knowledge a product of sensation or of pure thought?  All who had thus far taken part in this discussion had resembled partisans or advocates rather than disinterested judges.  They had given less attention to investigation than to the defense of the traditional theses of their schools; they had not endeavored to obtain results, but to establish results already determined; and, along with real arguments, popular appeals had not been despised.  Each of the opposing schools had given variations on a definite theme, and whenever timid attempts had been made to bring the two melodies into harmony they had met with no approval.  The proceedings thus far had at least made it evident to the unbiased hearer that each of the two parties made extravagant claims, and, in the end, fell into self-contradiction.  If the claim of empiricism is true, that all our concepts arise from perception, then not only the science of the suprasensible, which it denies, but also the science of the objects of experience, about which it concerns itself, is impossible.  For perception informs us concerning single cases merely, it can never comprehend all cases, it yields no necessary and universal truth; but knowledge which is not apodictically valid for every reasoning being and for all cases is not worthy the name.  The very reasons which were intended to prove the possibility of knowledge give a direct inference to its impossibility.  The empirical philosophy destroys itself, ending with Hume in skepticism and probabilism.  Rationalism is overtaken by a different, and yet an analogous fate—­it breaks up into a popular eclecticism.  It believes that it has discovered an infallible criterion of truth in the clearness and distinctness of ideas, and a sure example for philosophical method in the method of mathematics.  In both points it is wrong.  The criterion of truth is insufficient, for Spinoza and Leibnitz built up their opposing theories—­the pantheism of the one and the monadology of the other—­from equally clear and distinct conceptions; tried by this standard individualism is just as true as pantheism.  Mathematics, again, does not owe its unquestioned acceptance and cogent force to the clearness and distinctness of its conceptions, but to the fact that these are capable of construction in intuition.  The distinction between mathematics and metaphysics was overlooked, namely, that mathematical thought can transform its conceptions into intuitions, can generate its objects or sensuously present them, which philosophical thought