Another and kindred fact is explained, adding still further confirmation of the correctness of this theory. With perfect intentions men fulfil objective duty only in measure. Duty is only approximately accomplished, in varying degrees, from very faulty success to high grades of accuracy and completeness. A correct view of the ground of right must necessarily allow a consistent explanation of this fact. Sometimes the fact has been looked upon as inconsistent with any absolute dividing line between right and wrong, on one or the other side of which every action must fall. Not all good acts are perfect or faultless; not all evil ones are equally violations of duty. Of right actions some measure up better than others toward all that full duty requires. Dr. Martineau, partly in order to account for this scope of variety in moral correctness, urges a special definition of right and wrong: "Every action is right, which, in presence of a lower principle, follows a higher; every action is wrong, which, in presence of a higher principle, follows a lower."[61] By the great difference in the rank of moral motives the reason of men's differing grades in the ascending or descending scale of character seems to come into view. But while the definition furnishes a rule frequently serviceable for guidance in questions of duty, it fails to define the ground of right; for it leaves unsettled the very point in this question, viz.: why one principle (as a motive) _is_ morally "higher" or "lower" than another, or why some intentions or actions are right or wrong in any degree. And the offered explanation is unnecessary; for the unquestionable principle of moral requirement developed in relations, and discerned by the intuitive insight of the conscience fully explains the variety, when we remember the various degrees of accuracy and fulness with which these relations are understood and estimated. Every relation calling for duty is composite and complex, the various parts being often so connected as to come only partially or one-sidedly into view, preventing full insight of the moral demand, or accurate adjustment of sentiment and conduct to it. Rarely is any relation simple and alone. Often, indeed commonly, conscience has to decide duty as a resultant obligation out of very complicated and even antagonistic relationships. All this is amply sufficient to explain the different degrees in which the conduct meets duty. It is the necessary result of the impossibility of exactly fitting the moral sentiment or act to the demands of the moral relations. And the transparent explanation which this theory furnishes of the fact of such degrees strongly corroborates its scientific correctness. ==Verified in Moral Concepts.==