The moral argument has been presented in various forms by important writers of the t9th and 2oth centuries. Theories of ethics naturally fall into two classes, (I) those which take the fundamental concept in morals to be duty and the moral law; (2) those which take the idea of the Good to be fundamental. From both of these standpoints Theistic conclusions have been defended. James Martineau in his Types of Ethical Theory and A Study of Religion adopts on the whole the first, T. H. Green's Prolegomena to Ethics and W. R. Sorley's Moral Values and the Idea of God are salient representatives of the second, while Dr. Hastings Rashdall's Theory of Good and Evil combines to some extent both points of view.
There are three elements in the moral consciousness on which stress is laid in Theistic arguments. (a) The authority which the conscience attributes to the moral ideal. This unique authority cannot, it is urged, be explained on any view which does not allow us to find the moral law in some way built into the structure of the world, grounded in Reality. Other possible accounts of the source of the sense of obligation really issue in an explaining away of the moral "ought," and hence in the consequence that the fully moral life is irrational. Further, it is urged, the Theistic view is the view which most clearly enables us to hold that the moral law is not simply imposed externally but is the expression of the deepest self and also that it is no mere individual product, but of universal validity. (b) The "objectivity" of the moral ideal. The conscience cannot be satisfied with the belief that the
moral ideal is dependent upon opinion, whether of the individual or of groups. In spite of the obvious fact that moral ideas change, the moral life depends upon the conviction that the moral ideal itself is absolute. Though men's apprehension of it may grow, their apprehension does not create it. It may be argued that Theism gives us the most rational account of this aspect of the moral consciousness, since it suggests that the moral ideal may exist in the thought of God. (c) The content of the moral ideal, particularly when viewed in its social aspect. Though we know what we mean by progress, we cannot conceive any temporal con dition which would be the final goal of social progress. Unless therefore we are prepared to allow that progress is towards an end which is inherently unattainable, we are led to the thought of an End which is beyond the temporal order. Here again the theistic hypothesis appears to offer the most reasonable view, since it would hold that perfect communion with God and herein with all rational beings, is the nature of the highest Good. The central thought of the moral argument in all its forms is this : given man's moral experience at its highest we have the choice of regarding it as rational and significant, or of explaining it away as partially founded on a mistake with the probable consequence of weakening its effectiveness. If we choose to regard it as rational and significant Theism is the view of the world which will most adequately fulfil our demands.