Page:Philosophical Review Volume 2.djvu/177

No. 2.] this criterion is, we learn from the chapter on "The Discipline of Pure Reason." "Our reason," it is there stated, "ought to be compared to a sphere the radius of which may be determined from the curvature of the arc of its surface (corresponding to the nature of synthetical propositions a priori), which enables us likewise to fix the extent and periphery of it with perfect certainty." To determine the sphere of reason, which is the object of the Critique, what is given is the curvature of its arc, namely, a priori synthetic judgments. And the method of solving this problem is itself a priori, so that the results are absolutely indisputable. The subject of investigation for the Critique is a priori knowledge and the investigation itself (i.e. the Critique) is a priori knowledge.

It is a flattering view of one's own work that makes it as definitive and as absolute as a proposition in mathematics. But in Kant's case it was not the result of vanity. He believed in a mythological entity called reason, a self-poised organic unity, which was the source of a priori knowledge, and ought therefore, he supposed, to determine a priori what a priori knowledge it possessed and the conditions of it. Kant's absolutist pretensions are the natural counterpart of a heaven-scaling rationalism which will have "all or nothing." But since the outcome of the Critique is that we can have a priori knowledge only of objects of a possible sense-experience, it is not easy to see how the Critique itself can claim to be such a priori knowledge. If a priori knowledge is explained and justified as a condition of the possibility of experience, is it pretended that the Critique is also necessary to experience? If not, it is not a priori knowledge, has no claim to absoluteness or necessity, and remains merely an hypothesis to account for a (assumed) fact. Does not the Critique open with the declaration that all our knowledge begins with impressions of sense? Whence then your knowledge of the a priori forms?

I have called reason, in Kant's sense, a mythical faculty. Consider only what functions he attributes to it. It knows a priori; it criticises a priori what it knows a priori, and it