208. If we imagine these obscure operations under some such form as this, we get the advantage of being able to connect these insistent ideas in a coherent sequence with the more advanced phenomena of hysteria. We have seen that the insistent ideas are essentially a kind of small displacements of the habitual level of consciousness. They imply that some small but necessary scraps of supraliminal equipment have dropped, so to say, through chinks in the floor of the waking mind (as where the visual field has been narrowed hysterically), and have sunk to a point whence only hypnotic suggestion is likely to be able to call them back to use. Or in some cases we may go a step further, and say that these fixed ideas show us, not merely an ordinary supraliminal instinct functioning without due check, but rather a submerged and primitive instinct rising with a subliminal uprush into undesired prominence, and functioning wildly instead of remaining hidden and quiescent. That is to say, we have to do with an instability of the conscious threshold which often implies or manifests a disorderly or diseased condition of the hypnotic stratum, - of that region of the personality which, as we shall see, is best known to us through the fact that it is reached by hypnotic suggestion.

Now we shall find, I think, that all the phenomena of hysteria are reducible to the same general conception. To understand their many puzzles we have to keep our eyes fixed upon just these psychological notions - upon a threshold of ordinary consciousness, above which certain perceptions and faculties ought to be, but are not always, maintained, and upon a "hypnotic stratum" or region of the personality to which hypnotic suggestion appeals; and which includes faculty and perception which surpass the supraliminal, but whose operation is capricious and dreamlike, inasmuch as they lie, so to say, in a debateable region between two rules - the known rule of the supraliminal self, adapted to this life's experience and uses, and the conjectured rule of a fuller and profounder self, rarely reached by any artifice which our present skill suggests. Some of these conscious groupings have got separated from the ordinary stream of consciousness. These may still be unified in the subliminal, but they need to be unified in the supraliminal also.

The normal relation between the supraliminal and the subliminal may be disturbed by the action of either.

Let us now see how far this view, which I suggested in the S. P. R. Proceedings as far back as 1892,1 fits in with those modern observations of hysteria, in Paris and Vienna especially, which are transforming all that group of troubles from the mere opprobrium of medicine into one of the most fertile sources of new knowledge of body and mind.