There is thus left unexplained a totality which encompasses all the single members of experience--a unity compared to which the several categories are only a collection of fragments--an infinite which commands and regulates the finite concepts of the experiential intellect. But in the region of rational thought there is no objective and independent standard by which we can verify the conclusions of Reason. There are no definite objects, lying beyond the borders of experience, towards which it might unerringly turn; and its sole authentic use, accordingly, is to see that the understanding is thorough and exact, when it deals in the co-ordination of experiences. In this want of definite objects, Reason, whenever it acts for itself, can only fall into perpetual contradictions and sophistries. Pure Reason, therefore, the faculty of ideas, the organ of Metaphysics, does not of itself 'constitute' knowledge, but merely 'regulates' the action of the understanding. By this rigour of demonstration Kant dealt a deadly blow, as it seemed, to the dogmatic Metaphysics, and the Deism of his time. Hume had shaken the certainty of Metaphysics and thrown doubt upon Theology: but Kant apparently made an end of Metaphysics, and annihilated Deistic theology. The German philosopher, as Hegel has said and Heine has repeated, did thoroughly and with systematic demonstration what Voltaire did with literary graces and not without the witticisms with which the French executioner gives the _coup de grâce._ When a great idea had been degraded into a vulgar doctrine and travestied in common reality, the Frenchman met its inadequacies with graceful satire, and showed that these half-truths were not eternal verities. The German made a theory and a system of what was only a sally of criticism; and rendered the criticism wrong, by making it too consistent and too logical[1].