221 A. It is well known that a great variety of slight causes - hunger, fatigue, slight poisoning by impure air, a small degree of fever, etc. - are sometimes enough to produce a transient perturbation of personality of the most violent kind. I give as an instance the following account of a feverish experience, sent to me by the late Robert Louis Stevenson, from Samoa, in 1892 (and published in Proceedings S. P. R., vol. ix. p. 9). In Stevenson's paper on his own dreams, alluded to in 314, we have one of the most striking examples known to me of that helpful and productive subliminal uprush which I have characterised as the mechanism of genius. It is, therefore, interesting to observe how, under morbid conditions, this temperament of genius - this ready permeability of the psychical diaphragm - transforms what might in others be a mere vague and massive discomfort into a vivid though incoherent message from the subliminal storm and fire. The result is a kind of supraliminal duality, the perception at the same time of two personalities - the one rational and moral, the other belonging to the stratum of dreams and nightmare.

Vailima Plantation, Upoho, Samoan Islands, July 14th, 1892.

Dear Mr. Myers, - I am tempted to communicate to you some experiences of mine which seem to me (ignorant as I am) of a high psychological interest.

I had infamous bad health when I was a child and suffered much from night fears; but from the age of about thirteen until I was past thirty I did not know what it was to have a high fever or to wander in my mind. So that these experiences, when they were renewed, came upon me with entire freshness; and either I am a peculiar subject, or I was thus enabled to observe them with unusual closeness.

Experience A

During an illness at Nice I lay awake a whole night in extreme pain. From the beginning of the evening one part of my mind became possessed of a notion so grotesque and shapeless that it may best be described as a form of words. I thought the pain was, or was connected with, a wisp or coil of some sort; I knew not of what it consisted nor yet where it was, and cared not; only I thought, if the two ends were brought together, the pain would cease. Now all the time, with another part of my mind, which I ventured to think was myself I was fully alive to the absurdity of this idea, knew it to be a mark of impaired sanity, and was engaged with my other self in a perpetual conflict. Myself had nothing more at heart than to keep from my wife, who was nursing me, any hint of this ridiculous hallucination; the other was bound that she should be told of it and ordered to effect the cure. I believe it must have been well on in the morning before the fever (or the other fellow) triumphed, and I called my wife to my bedside, seized her savagely by the wrist, and looking on her with a face of fury, cried: "Why do you not put the two ends together and put me out of pain ? "

Experience B

The other day in Sydney I was seized on a Saturday with a high fever. Early in the afternoon I began to repeat mechanically the sound usually written "mhn," caught myself in the act, instantly stopped it, and explained to my mother, who was in the room, my reasons for so doing. "That is the beginning of the mind to wander," I said, "and has to be resisted at the outset." I fell asleep and woke, and for the rest of the night repeated to myself mentally a nonsense word which I could not recall next morning. I had been reading the day before the life of Swift, and all night long one part of my mind {the other fellow) kept informing me that I was not repeating the word myself, but was only reading in a book that Swift had so repeated it in his last sickness. The temptation to communicate this nonsense was again strongly felt by myself, but was on this occasion triumphantly resisted, and my watcher heard from me all night nothing of Dean Swift or the word, nothing but what was rational and to the point. So much for the two consciousnesses when I can disentangle them; but there is a part of my thoughts that I have more difficulty in attributing.

One part of my mind continually bid me remark the transrational felicity of the word, examined all the syllables, showed me that not one was in itself significant, and yet the whole expressed to a nicety a voluminous distress of one in a high fever and his annoyance at and recoil from the attentions of his nurses. It was probably the same part (and for a guess the other fellow) who bid me compare it with the nonsense words of Lewis Carroll as the invention of a lunatic with those of a sane man. But surely it was myself (and myself in a perfectly clear-headed state) that kept me trying all night to get the word by heart, on the ground that it would afterwards be useful in literature if I wanted to deal with mad folk. It must have been myself, I say, because the other fellow believed (or pretended to believe) he was reading the passage in a book where it could always be found again when wanted.