Page:Popular Science Monthly Volume 50.djvu/529

Rh seized upon by somebody. One refers hypnotic states to excessive blood supply, another to diminished blood supply, another to accumulation of waste products in the blood, another to inhibition of the association paths, another to inhibition of the frontal region, another to inhibition of one hemisphere, another to inhibition of the entire cortex, and so on. There may be an element of truth in some of these theories, but it is certain that no one is sufficient to account for all the facts, even if the alleged super-normal facts be excluded as non-proved.

In fact, we know very little indeed about the brain processes which are immediately related to consciousness, and consequently many psychologists are reluctant to resort to them for explanations of what goes on in consciousness. They prefer to limit the inquiry to the facts and laws of mind and to formulate the phenomena of suggestibility and automatism in mental terms alone. It is not possible for me to analyze these theories here, as each presupposes a knowledge of the particular psychological point of view from which it is conceived. The ideas of inhibition of attention, interference with association, inhibition of will, influence of imagination and expectation, figure largely in all these theories. That which I have been developing in these pages belongs to this type, but is distinguished by its free use of conceptions derived from the theory of dependence. Assuming that consciousness depends upon and indicates the existence of physical processes, that these physical processes have the attributes of other physical forces, that they in some way coalesce and interact in the brain cortex, I borrowed these physical conceptions and applied them directly to those mental phenomena which we regard as dependent upon the physical. Thus, if the simultaneous grasping of several mental facts indicates a coalescence of their physical bases, and vice versa, then inability to become conscious of any mental fact the physical basis of which we have reason to believe exists would indicate that its physical basis had failed to coalesce with the others. In such cases I described the mental fact as itself "cut off from" or "dissociated from" the other mental states, although, manifestly, mental states, which do not themselves occupy space, can not be spatially cut off from or separated from anything whatever. The phenomena of suggestibility I ascribed to the removal through this dissociation of the checks and counterchecks exerted by mental states upon one another, thus allowing suggested sensations and ideas to work out their results more freely than usual.

Analogous conceptions have been worked out by other writers without explicit reference to the physical basis of consciousness. Thus, Dr. Hans Schmidkunz, in a bulky and learned but badly written book (Psychologie der Suggestion, Munich, 1892), makes