38 J. S. HALDANE. In order to get a clearer idea of the conception which we have now reached of the nature of life, we may compare this new conception with that of reciprocity. The parts of a whole of reciprocity are thought of as having a certain independence of their own, manifested in properties which they possess individually, apart from their relation to the whole. And this independence is an essential part of the conception. For it is not merely that the parts seem independent when we leave out of account the whole ; but it is of the essence of a whole of reciprocity that its parts are at the same time dependent on it and independent of it. In so far as the parts participate in the system formed by the whole, the influence of the whole in them is not the influence of something foreign to themselves. They are not deter- mined by another, as in causal determination, but by them- selves through another. In. as far, however, as regards that in the parts with respect to which they are essentially independent, in so far is the influence of the whole in them a foreign determining influence. It is thus true of a whole of reciprocity that its parts are at the same time free and determined by another. In the case, however, of the con- ception of a whole which determines the parts through and through it is different. For, so far as concerns what is essential to the conception, there is nothing in the parts that is not a manifestation of the whole. The shape, consistence, size, and other properties in which the inde- pendence of the parts previously seemed to show itself, are now only manifestations of the whole. In all that the parts do and all that they are they only show forth the whole. It follows from this that if we speak of them as determined by the whole, we use the word ' determined ' in a sense altogether different from its ordinary sense. For, since the parts are what they are, only as taking part in the whole, there can clearly be nothing foreign to them in. their deter- mination. In this apparent determination they are only manifesting what they are in themselves. I shall devote the rest of this article to showing how this conception may be brought to bear on specific biological questions. Some apparent difficulties which suggest them- selves in connexion with these questions will at the same time be considered. In the phenomena of reflex action those who uphold the belief that the organism is at bottom only a complicated piece of mechanism find what appears to afford to that belief a reasonable basis. If the finger be lightly and quickly drawn across the sole of the foot it will be noticed that the
