[385:11] Royce: _Conception of God_, pp. 19, 43-44. This argument is well summarized in Green's statement that "the existence of one connected world, which is the presupposition of knowledge, implies the action of one self-conditioning and self-determining mind." _Prolegomena to Ethics_, p. 181. [387:12] Kant: _Critical Examination of Practical Reason_. Translated by Abbott in _Kant's Theory of Ethics_, p. 180. [391:13] Quoted from McTaggart: _Op. cit._, pp. 231-232. [393:14] Emerson: _Op. cit._, pp. 30-31. [394:15] Royce: _The World and the Individual, First Series_, p. 465. CHAPTER XII CONCLUSION [Sidenote: Liability of Philosophy to Revision, Due to its Systematic Character.] § 195. One who consults a book of philosophy in the hope of finding there a definite body of truth, sanctioned by the consensus of experts, cannot fail to be disappointed. And it should now be plain that this is due not to the frailties of philosophers, but to the meaning of philosophy. Philosophy is not additive, but reconstructive. Natural science may advance step by step without ever losing ground; its empirical discoveries are in their severalty as true as they can ever be. Thus the stars and the species of animals may be recorded successively, and each generation of astronomers and zoölogists may take up the work at the point reached by its forerunners. The formulation of results does, it is true, require constant correction and revision--but there is a central body of data which is little affected, and which accumulates from age to age. Now the finality of scientific truth is proportional to the modesty of its claims. Items of truth persist, while the interpretation of them is subject to alteration with the general advance of knowledge; and, relatively speaking, science consists in items of truth, and philosophy in their interpretation. The liability to revision in science itself increases as that body of knowledge becomes more highly unified and systematic. Thus the present age, with its attempt to construct a single comprehensive system of mechanical science, is peculiarly an age when fundamental conceptions are subjected to a thorough reëxamination--when, for example, so ancient a conception as that of matter is threatened with displacement by that of energy. But philosophy is _essentially unitary and systematic_--and thus _superlatively liable to revision_. [Sidenote: The One Science and the Many Philosophies.]