My aim here is by no means to assert that this is how it really is concerning the specific grav ity of the variety of matters, but only to establish, on the basis of a principle of pure understanding, that the nature of our perceptions makes an explanation of this sort possible, and that it is false to assume that the real in appearance is always equal in degree and differs only in aggregation and its extensive magnitude, especially when this is allegedly asserted on the basis of a principle of understanding a priori.