170 HENRY SIDGWICK : comprehensive account which he gives of it, is stated to be a " Theory of the Good as Human Perfection ". The Perfec- tion which is thus taken to be the ultimate end of rational conduct is otherwise described as the " realisation," " de- velopment " or " completion " of human " faculties " or " capabilities ". If we ask further to what part of man's apparently composite nature these " faculties " or " capabili- ties " belong, we are told that they are " capabilities of the spirit which is in man " to which, again, a " divine " or " heaven-born " nature is attributed. The realisation of these capabilities is, in fact, a " self-realisation of the divine principle in man " ; that is, of the " one divine mind " which " gradually reproduces itself in the human soul ". " God," we are elsewhere told, " is a being with whom the human spirit is identical, in the sense that He is all which the human spirit is capable of becoming " (p. 198). Hence the conception of the Divine Spirit presents to the man who is morally aspiring an " ideal of personal holiness " with which he contrasts his own personal un worthiness. If, however, we are to obtain from these notions anything more than a vague emotional thrill, which, however salutary it may be, cannot carry with it any ethical instruction, we must go on to ask how this relation of man to God is philo- sophically known, and what definite and reasoned content
- can be given to this notion of a Divine Spirit. It would
appear from the order of Green's treatise, and the pro- portions of its parts, that an answer to these questions was intended to be given in Book i., on the " Metaphysics of Knowledge ". Here we are certainly introduced to a " spiritual principle in nature " corresponding to the spiritual principle implied in all human knowledge or experience. It is argued (pp. 30, 32) that to constitute the " single, all- inclusive, unalterable system of relations," which we find in nature, properly understood, something beyond nature is needed : " something which renders all relations possible," and supplies the " unity of the manifold " which is involved in the existence of these relations. " A plurality of things cannot of themselves unite in one relation, nor can a single thing of itself bring itself into a multitude of relations there must therefore be something other than the manifold things themselves which combines them." Such a " combining agency " in each one's experience is his own intelligence, his intelligent self which unites the objects of his experience while distinguishing itself from them. Hence if we suppose nature to be real " otherwise than merely as for us," we must " recognise as the condition of this reality
