801. The reader, however, who has followed me thus far must be well aware that a large class of phenomena, of high importance, is still awaiting discussion. Motor automatisms, - though less familiar to the general public than the phantasms which I have classed as sensory automatisms, - are in fact even commoner, and even more significant.

Motor automatisms, as I define them, are phenomena of very wide range. We have encountered them already many times in this book. We met them in the first place in a highly developed form in connection with multiplex personality in Chapter II (Disintegrations Of Personality). Numerous instances were there given of motor effects, initiated by secondary selves without the knowledge of the primary selves, or sometimes in spite of their actual resistance. All motor action of a secondary self is an automatism in this sense, in relation to the primary self. And of course we might by analogy extend the use of the word still further, and might call not only post-epileptic acts, but also maniacal acts, automatic; since they are performed without the initiation of the presumedly sane primary personality. Those degenerative phenomena, indeed, are not to be discussed in this chapter. Yet it will be well to pause here long enough to make it clear to the reader just what motor automatisms I am about to discuss as evolutive phenomena, and as therefore falling within the scope of this treatise; - and what kind of relation they bear to the dissolutive motor phenomena which occupy so much larger a place in popular knowledge.

802. In order to meet this last question, I must here give more distinct formulation to a thesis which has already suggested itself more than once in dealing with special groups of our phenomena.

It may be expected that supernormal vital phenomena will manifest themselves as far as possible through the same channels as abnormal or morbid vital phenomena, when the same centres or the same synergies are involved.

To illustrate the meaning of this theorem, I may refer to a remark long ago made by Edmund Gurney and myself in dealing with "Phantasms of the Living," or veridical hallucinations, generated (as we maintained) , not by a morbid state of the percipient's brain, but by a telepathic impact from an agent at a distance. We observed that if a hallucination - a subjective image - is to be excited by this distant energy, it will probably be most readily excited in somewhat the same manner as the morbid hallucination which follows on a cerebral injury. We urged that this is likely to be the case - we showed ground for supposing that it is the case - both as regards the mode of evolution of the phantasm in the percipient's brain, and the mode in which it seems to present itself to his senses.

And here I should wish to give a much wider generality to this principle, and to argue that if there be within us a secondary self aiming at manifestation by physiological means, it seems probable that its readiest path of externalisation - its readiest outlet of visible action, - may often lie along some track which has already been shown to be a line of low resistance by the disintegrating processes of disease. Or, varying the metaphor, we may anticipate that the partition of the primary and the secondary self will lie along some plane of cleavage which the morbid dissociations of our psychical synergies have already shown themselves disposed to follow. If epilepsy, madness, etc, tend to split up our faculties in certain ways, automatism is likely to split them up in ways somewhat resembling these.

This argument might be illustrated by various physical analogies. Let us choose as a simple one a musical instrument of limited range. The consummate musician can get effects out of this instrument which the ordinary player cannot rival. But he does this at the risk of evoking occasional sounds such as only the most blundering of beginners is wont to produce.

Savages take epilepsy for inspiration. They are thus far right, that epilepsy is (so to speak) the temporary destruction of the personality in consequence of its own instability, whereas inspiration was assumed to be the temporary subjugation of the personality by invasion from without. The one case (if I may use the metaphor) was a spontaneous combustion; the other an enkindlement by heavenly fire. In less metaphorical language, explosion and exhaustion of the highest nervous centres must have somewhat the same look, whatever may have been the nature of the stimulus which overcame their stability.