We readily grant that all our empirical knowledge is confined to phenomena in their orders of co-existence, succession, and resemblance. "To our objective perception and comparison nothing is given but qualities and changes; to our inductive generalization nothing but the shifting and grouping of these in time and space." Were it, however, our immediate concern to discuss the question, we could easily show that sensationalism has never succeeded in tracing the genetic origin of our ideas of space and time to observation and experience; and, without the _à priori_ idea of _space_, as the place of bodies, and of _time_, as the condition of succession, we can not conceive of phenomena at all. If, therefore, we know any thing beyond phenomena and their mutual relations; if we have any cognition of realities underlying phenomena, and of the relations of phenomena to their objective ground, it must be given by some faculty distinct from sense-perception, and in some process distinct from inductive generalization. The knowledge of real Being and real Power, of an ultimate Reason and a personal Will, is derived from the apperception of pure reason, which affirms the necessary existence of a Supreme Reality--an Uncreated Being beyond all phenomena, which is the ground and reason of the existence--the contemporaneousness and succession--the likeness and unlikeness, of all phenomena. The immediate presentation of phenomena to sensation is the _occasion_ of the development in consciousness of these _à priori_ ideas of reason: the possession of these ideas or the immanence of these ideas, in the human intellect, constitutes the original _power_ to know external phenomena. The ideas of space, time, power, law, reason, and end, are the logical antecedents of the ideas of body, succession, event, consecution, order, and adaptation. The latter can not be conceived as distinct notions without the former. The former will not be revealed in thought without the presentation to sense, of resistance, movement, change, uniformity, etc. All actual knowledge must, therefore, be impure; that is, it must involve both _à priori_ and _à posteriori_ elements; and between these elements there must be a necessary relation.