LIFE AND MECHANISM. 37 To get over the difficulty we must conclude that the determination of the parts as members of a system extends, not only to their behaviour relatively to one another, but also to properties in them which they seemed to possess independently. For only in this way can we account for the circumstance that the ' design ' which is seen in the parts is not accidentally present in them, apart from the fact of their determination as members of the system, but is dependent on this fact. There is, then, not merely a reciprocal determination of one another by the parts as subordinate independent wholes ; but this reciprocal deter- mination extends right through the parts. That is to say, what appeared to belong to the parts independently of their relation to the whole, for instance their size, shape, and structure, is really only the manifestation in the parts of the influence of the whole. 1 The nature of this conception of the whole determining the parts through and through, may be made more clear if we consider its application in a much less complicated case. The general contour, at any moment, of that part of the earth's surface which is covered by the sea is due, not merely to the mutual attraction between all parts of the earth, but also, as shown by the tides, to the mutual attraction between the earth and other members of the solar system. We may therefore consider that the contour of the sea is a manifesta- tion in the earth of the influence of the solar system regarded as a whole. There is thus in the case even of the solar system something more than a reciprocal determination by the parts of one another as subordinate independent wholes. For, so far as our illustration is concerned, the influence of the whole manifests itself right through one of these sub- ordinate wholes, and determines its shape, which is one of the properties as to which the parts of a whole of reciprocity are independent. The general conception of reciprocity must here give way to that of the whole determining the parts through and through, so that their essential indepen- dence of the whole is lost. Here again it may be well to state that in the application to biological phenomena of this idea of the whole determining the parts through and through, the existence of no mysterious force is postulated. All that is done is to take a more concrete and comprehensive view of forces with which physiology familiarly deals, the previous view having turned out to be narrow and abstract. 1 The word ' whole ' is used here, not in the sense of a spatial whole, but with a significance which the context sufficiently determines.
