In attempting to approach the task of building up a world-view based on ethical experience, it became unavoidable to consider the method by which the approach might be made, and for this purpose to contrast the methods of science and the methods of ethics. Science, as we have seen, collects its bricks and builds its house by composition. Science analyzes phenomena into units, which it then combines. The mystery is how science can achieve certainty in respect to certain phenomena of nature without previous knowledge of the whole of nature. Kant’s answer is that there is partial congruity between the mental functions and the data that come to us from the unknown. Kant’s _Critique of Pure Reason_ faces in two directions. It expels the older metaphysics which assumed that the empirical world is rational throughout, or rationalizable, and which thence argued the existence of the unconditioned as necessarily implied in the existence of the conditioned, and of a first cause as actually implied in the chain of causes and effects. Kant contends that there is an irrational element, namely, bare juxtaposition (part outside part), and bare sequence (part before and after part), while the logical or rational relation implies that the part is to be conceived as implicit in the whole. Juxtaposition and sequence, therefore, can never be completely rationalized. On the other hand, Kant undertakes to prove that whatever of reality we know is traceable to the projection of the rational factor upon the irrational. One might even say that, according to Kant, the mind itself produces the irrational factor, since the intuitions of space and time are according to him, functions of the mind itself—the mind setting up a manifold so constituted as to receive sense impressions. At any rate the capital point to which we were led up was that science puts her foot on _terra firma_ in a restricted area, without reference to what lies beyond, while if we are to proceed in ethics at all, we must begin with some ideal plan of the whole, since in ethics we are not interpreting a foreign nature, but act upon natures similar to our own; and since, in the case of conduct, there is no such partial concurrence of the rational and irrational as in physics, no one of the so-called moral modes of behavior being moral when taken separately. Hence the conclusion that there is no possibility of establishing the conception of worth unless we have some ideal of the whole in which and in relation to which the incomparable worthwhileness of a human being can be made good.