The arrangement and composition of an Encyclopaedia of the Philosophical Sciences demands from its Editor more than a systematic justification of his undertaking. He must also, and above all, give the grounds of the implications contained in the very name and title. It would seem certain that, before any science can hope to attain, or lay stress upon, a fairly secure starting-point for further progress by means of a Bibliography or Encyclopaedia, it must have already reached a certain definite stage of development. Even in the drawing up of a Bibliography, which involves nothing more than an apparently mechanical and technical collecting and arranging of contributions already made, the conception of the science concerned must be firmly grasped; for it is not a question of putting together everything which has been produced on the subject, but of selecting that which falls within a definite and comprehensive conception of the science. Only in that way can the historical progress of the particular science be secured and the contributions already made serve as a criterion for later writers. If, then, the modest compilation of a Bibliography involves a certain stage of maturity, of unity of direction on the part of a science both as regards matter and method, how much more the compilation of an Encyclopaedia! But if we may confront the task of collecting together the results of a particular sphere of scientific research not without joy and confidence, we cannot attempt to gather together and present as final the results of a period of philosophical speculation without much misgiving. For, however we may understand the idea of Philosophy, whether as the comprehending of spirit . . .