problems, and that all existence is so fundamentally of one type that we can argue from the sensuous to the supersensuous, from appearance to reality. When they fell into difficulties, they pleaded the insufficiency of human reason, and yet were all the while unquestioningly relying upon it in the drawing of the most tremendous inferences. Such, for instance, are the assumptions which underlie Moses Mendelssohn’s contention that since animals as well as men agree in the apprehension of space, it must be believed to be absolutely real.[84] These assumptions also determine Priestley’s assertion that though every event has its cause, there is one causeless happening, namely, the creative act to which the existence of the world is due.[85] On such terms, metaphysics is too patently easy to be even plausible. “Indifference, doubt, and, in final issue, severe criticism, are truer signs of a profound habit of thought.”[86] The matter of experience affords no data for metaphysical inference. In the _a priori_ forms of experience, and there alone, can metaphysics hope to find a basis, if any basis is really discoverable. This is Kant’s reason for so emphatically insisting that the problem of the _Critique_ is to determine “how much we can hope to achieve by reason, when all the material and assistance of experience is taken away.”[87] But in keeping only this one point in view Kant greatly misrepresents the problems and scope of the _Critique_. Throughout the _Preface_ he speaks the language of the _Aufklärung_. Even in the very act of limiting the scope of reason, he overstresses its powers, and omits reference to its empirical conditions. It is well to contrast this teaching with such a passage as the following: “The position of all genuine idealists from the Eleatics to Berkeley is contained in this formula: ‘All cognition through the senses and experience is nothing but mere illusion, and only in the ideas of pure understanding and Reason is there truth.’ The fundamental principle ruling all my idealism, on the contrary, is this: ‘All cognition of things solely from pure understanding or pure Reason is nothing but mere illusion, and only in experience is there truth.’”[88]