The conception of morality as a system of positive Divine Law, and the ‘juridical method’ which is said to mark early Christian writers on ethics, is perhaps attributable to the growth of an imperial spirit in the Church when she found herself confronted with the task of reducing to order the social chaos into which the fall of the Empire plunged Europe. S. Leo may be said to embody this spirit in a majestic personal form. The mark of Roman authority rests on the ordinances of the Church of this period. It may be that her rules of duty wear something of the aspect of a fixed, unvarying code. The moral problems with which she has to deal are comparatively simple; they admit of clear, concise treatment, in accordance with a fixed system of discipline; sharp distinctions are possible: and the Gospel thus presents to the world the features of an external Law.

Be this as it may, widely different conditions seem now to demand a definite system of Christian duty,—a study of ‘special’ or ‘applied ethics.’ The main feature of modern life is not social disorganization, but complexity of relationships; and although in the abstract no such thing is possible as a ‘conflict of duties;’ yet it is clear that duty is not always simple, or obvious. We need in fact something like a system of casuistry; of ethics applied to novel spheres, and special points of obligation.