We have said that moral investigation, when conducted on the Socratic method, is as truly inductive as any process in physical science. But there is a {61} distinction, and that a very vital one. In moral inquiries we can often start directly with deduction from some inward principle, implanted in the human mind by the Author of our being. The love of truth, for instance, as above set forth, is one of those principles; our general term in this case we bring with us; and any induction which we may require is not to prove the existence of such an instinct, but to verify, to extend, and to correct our notions of its applicability, or perhaps merely to confirm us in our original sacred faith, by showing in detail that society never has existed, and in fact never can exist, without that regard to truth in all dealings of man with man, the necessity of which we had asserted originally from the constraining power of the inborn moral imperative decree. And if our moral principles always existed in a vivid and healthy state, there might be little need for the slow retrogressive process of induction in ethics; but as these instincts are peculiarly liable to be enfeebled, curtailed, and perverted by individual neglect, as well as social constraint, the corrective and cathartic process by induction on a more extended basis becomes necessary for the worst men, and not without utility for the best. At the same time, of the noblest minds in the moral world it may always be asserted that their whole life has been rather a practical deduction from lofty truths given by original inspiration from the Divine Source of all vitality than the product of any induction from an acquired survey of facts. The work of a great moral teacher or reformer, such as the apostle Paul or Thomas Chalmers, is in fact a creation as much as the poems of a Shakespeare or the paintings of a Raphael; and has a {62} manifest affinity also with the grand deductions of mathematical genius, which, from the postulated form of a triangle, a circle, or other figure of which the conditions are dictated by the mind, not gathered from observation, evolves an array of the most curious relations, of which no one had hitherto dreamed, and which are each one as necessary and absolutely true as the postulate from which they came forth. Exactly so with Morals. An admitted postulate--say of truthfulness, of love, or whatever inborn original principle you please,--may be worked out as the world advances into ever new and more noble practical applications, which shall be as unconditionally right as the original diving force out of which they grew. And as the propositions of Euclid can be proved _a posteriori_ by empirical measurements, though they do not depend on these measurements, in the same way the great truths of ethical science may be proved from induction, though in the case at least of great moral teachers they are the direct and pure products of an inspired deduction.