These thoughts have brought us to the most essential considerations of this lecture. Whether the Positive _savant_ puts in a plea of ignorance or of blank negation, we care not. We will treat it as a challenge thrown down, and do our best to meet it. Succeed or not, we will take no refuge in ambiguities, but maintain a truly positive assertion. We say that the world we live in is not one world, but two,[171] distinguishable through the laws by which each is governed. There exists such a thing as phenomenal law; we accept the fact. But distinct, broadly distinct, apart in its working, its elements, and its final result, is moral law. An appeal lies to facts, and we shall try to justify our assertion. The mode of proof now to be adopted is not metaphysical. I mention the circumstance because investigations into mind are apt to be confounded with metaphysic, and are then supposed too difficult to deserve attention. My argument will demand nothing beyond a hearing and a scrutiny. It will consist of just so much mental dissection as may be needful to show, first, a structural law of our inward nature, and, secondly, to illustrate its workings and effects. These two sets of facts will be placed side by side, in order that each may check the other, and that their coincidence may also (as I hope it will) furnish a fresh and sufficient proof of the contrast between moral and material law. Everybody knows how convincing are, and ought to be, facts separately ascertainable, yet converging into one and the same conclusion. One form of speech almost unavoidable ought to be remarked beforehand. I mean the word freedom as applied to the human will and its volitions. When compelled to use it, I shall do so only in the sense of philosophic as contrasted with theological free will. By philosophic freedom I understand that sort and degree of active choice free from constraint which is required for the idea of responsibility, an idea universally agreed on by divines opposed to each other on the point of theological freewill. By this last-named idea I understand supposed powers of spiritual attainment, which go to make up a notion of self-sufficing moral strength. With it the present lecture, being purely philosophical, can have nothing whatever to do, but I should much deplore misconception, because any theory of self-sufficingness would be repugnant to my own personal convictions.