The purpose of this essay in descriptive psychology is to provide a survey of a comprehensive aspect of human psychic endowment. The very definition of psychology as the science of consciousness has tended to focus attention upon conditions of high introspective lucidity, and, by implication, to look upon areas from which such illumination is withdrawn, as quite too obscurely lighted for profitable examination. Thus casually visited, and with no vital share in the psychologist's concerns, the abode of the subconscious has drifted into the service of a lumber-room, in which to deposit what finds no place in the mind's active economies.
The word subconscious has a dubious sound; and those to whom it brings slight illumination associate it with questionable phenomena of rare occurrence and unusual significance. It should be a homely term; and its place is close to the hearth of our psychological interests. The word, in company with others of analogous origin, has been made the symbol of an inner mystery, a pale double of ourselves, disporting itself strangely when our oversight is relaxed, and capable, if only . . .