I need hardly say that as regards the inner nature of this close co-ordination, this central government, science can at present tell us little or nothing. The growth of the nervous mechanism may be to some extent deciphered; but how this mechanism is centrally governed; what is the tendency which makes for unity; where precisely this unity resides, and what is its exact relation to the various parts of the multicellular organism--all these are problems in the nature of _life_, to which as yet no solution is known. The needed clue, as I believe, can be afforded only by the discovery of laws affecting primarily that unseen or spiritual plane of being where I imagine the origin of life to lie. If we can suppose telepathy to be a first indication of a law of this type, and to occupy in the spiritual world some such place as gravitation occupies in the material world, we might imagine something analogous to the force of cohesion as operating in the psychical contexture of a human personality. Such a personality, at any rate, as the development of higher from lower organisms shows, involves the aggregation of countless minor psychical entities, whose characteristics still persist, although in a manner consistent with the possibility that one larger psychical entity, whether pre-existent or otherwise, is the unifying continuum of which those smaller entities are fragments, and exercises over them a pervading, though an incomplete, control. It is plainly impossible to say beforehand what will be the relation to the ordinary stream of consciousness of a personality thus composed. We have no right to assume that all our psychical operations will fall at the same time, or at any time, into the same central current of perception, or rise above what we have called the ordinary conscious threshold. We can be sure, in fact, that there will be much which will not so rise; can we predict what _will_ rise? We can only reply that the perception of stimuli by the supraliminal consciousness is a kind of exercise of function; and that here, as in other cases where a function is exercised, part of its range will consist of such operation as the primary structure of the organism obliges it to perform, and part will consist of such operation as natural selection (after the structure has come into being) has trained it to perform. There will be something which is structurally inevitable, and something which was not structurally inevitable, but which has proved itself practically advantageous.