Furthermore, on the question to which these considerations lead up; that of the ultimate interpretation we are to put on the reality of the world, the issue is not so indeterminate as it might seem from some points of view. Taking it that the very notion of metaphysics excludes the material and the physical as ultimate types of the real, we are left with the notions of the immaterial and the psychic; and while the former is indefinite, it is a fact that in the psychic and especially in the form of it which man realizes in his own experience, he finds an intelligible type and the only one that is available to him for the definition of the immaterial. He has his choice, then, either to regard the world as _absolutely opaque_, showing nothing but its phenomenal dress which ceases to have any meaning; or to apply to the world's inner nature the intelligible types and analogies of his own form of being. That this is the alternative that is embodied in the existence of metaphysics is clearly demonstrated by the fact that the metaphysical interpretation embodies itself in the categories of _reason_, _design_, _purpose_, and _aim_. Whatever difficulties we may encounter, then, in the _use_ and application of the _psychic analogy_ in determining the nature of the real, it is clear that its employment is inevitable and indispensable. Let us, then, employ the term _rational_ to that characterization of the nature of things which to metaphysics is thus inevitable and indispensable. The world must in the last analysis be _rational_ in its constitution, and its agencies and forms of being must be construed as _rational_ in their type.