But as we go further we can no longer limit the problem in this way,--to the activities of the automatist's subliminal self. We cannot always assume that some portion of the automatist's personality gets at the supernormal knowledge by some effort of its own. Our evidence, as we know, has pointed decisively to telepathic impacts or influences from without. What, then, is the mechanism here? Are we still to suppose that the automatist's subliminal self executes the movements--obeying somehow the bidding of the impulse from without? or does the external agent, who sends the telepathic message, himself execute the movements also, directly using the automatist's arm? And if telekinetic movements accompany the message (a subject thus far deferred, but of prime importance), are we to suppose that these also are effected by the percipient's subliminal self, under the guidance of some external spirit, incarnate or discarnate? or are they effected directly by that external spirit? We cannot really say which of these two is the easier hypothesis. From one point of view it may seem simpler to keep as long as we can to that acknowledged _vera causa_, the automatist's subliminal self; and to collect such observations as may indicate any power on its part of producing physical effects outside the organism. Such scattered observations occur at every stage, and even Mrs. Newnham (I may briefly observe in passing) thought that her pencil, when writing down the messages telepathically derived from her husband, was moved by something other than the ordinary muscular action of the fingers which held it. On the other hand, there seems something very forced in attributing to an external spirit's agency impulses and impressions which seem intimately the automatist's own, and at the same time refusing to ascribe to that external agency phenomena which take place outside the automatist's organism, and which present themselves to him as objective facts, as much outside his own being as the fall of the apple to the ground. Reflecting on such points--and once admitting this kind of interaction between the automatist's own spirit and an external spirit, incarnate or discarnate--we find the possible combinations presenting themselves in perplexing variety;--a variety both of agencies on the part of the invading spirit, and of effects on the part of the invaded spirit and organism. What is that which invades? and what is that which is displaced or superseded by this invasion? In what ways may two spirits co-operate in the possession and control of the same organism?