Recently, much has been written on the doctrine of duplex personality, notably by Mr. F. W. H. Myers, in a series of papers read before the Society of Psychical Research. Professor Newbold has also written very entertainingly and instructively on this subject. While not fully accepting the theory of "duplex personality," _i. e._, active consciousness and _subliminal consciousness_ (Myers' name for the pseudo-dormant consciousness), as having been proven, Newbold says: "Of all the theories developed from the point of independence, Mr. Myers' is the most comprehensive in its scope, is kept in most constant touch with what the author regards as facts, and displays the greatest philosophic insight."[101] According to the theory of duplex personality, many instincts, desires, and emotions have been crowded out of the active consciousness and have been relegated to the pseudo-dormant consciousness. This has been brought about by a "process of selection out of an infinity of possible elements solely on the grounds of utility." Thus the _cause_ for our horror of incest is hidden away in our subliminal consciousness; yet we cannot but think, with Westermarck, that this instinct is but the result of natural selection,[102] the utility of the factor or factors occasioning it being no longer in evidence or required. Again, at certain seasons, man is seized with _waldliebe_ (forest-love) and longs to flee from the haunts of men, and, with gun and rod, to revert, as far as possible, to the state of his savage ancestors. The desire is safely hidden away in his subliminal consciousness until favoring circumstances tempt it forth. It is not alone in "sleep, dreams, hypnosis, trance, and ecstacy that we see a temporary subsidence of the upper consciousness and the upheaval of a subliminal stratum"; there are many other states and many other causes for this strange psychical phenomenon. [101] Newbold: _Appleton's Popular Science Monthly_, February, 1897, p. 516. [102] Westermarck: _History of Human Marriage_, p. 352.