th the mysterious but undisputed phenomena of hypnotism will realize
how naturally this question arises, and how difficult it is to answer it
otherwise than in the affirmative. Every one knows Mr. Louis Stevenson's
wonderful story of "Dr. Jekyll and Mr. Hyde." The dual nature of man,
the warfare between this body of sin and death, and the spiritual
aspirations of the soul, forms part of the common stock of our orthodox
belief. But the facts which recent researches have brought to light seem
to point not to the old theological doctrine of the conflict between
good and evil in one soul, but to the existence in each of us of at
least two distinct selfs, two personalities, standing to each other
somewhat in the relation of man and wife, according to the old ideal
when the man is everything and the woman is almost entirely suppressed.

Every one is familiar with the phenomenon of occasional loss of memory.
Men are constantly losing consciousness, from disease, violence, or
violent emotion, and emerging again into active life with a gap in their
memory. Nay, every night we become unconscious in sleep, and rarely, if
ever, remember anything that we think of during slumber. Sometimes in
rare cases there is a distinct memory of all that passes in the sleeping
and the waking states, and we have read of one young man whose sleeping
consciousness was so continuous that he led, to all intents and
purposes, two lives. When he slept he resumed his dream existence at the
point when he waked, just as we resume our consciousness at the point
when we fall asleep. It was just as real to him as the life which he
lived when awake. It was actual, progressive, continuous, but entirely
different, holding no relation whatever to his waking life. Of his two
existences he preferred that which was spent in sleep, as more vivid,
more varied, and more pleasurable. This was no doubt an extreme and very
unusual case. But it is not impossible to conceive the possibility of a
continuous series of connected dreams, which would result in giving us a
realizing sense of leading two existences. That we fail to realize this
now is due to the fact that our memory is practically inert or
non-existent during sleep. The part of our mind which dreams seldom
registers its impressions in regions to which on waking our conscious
personality has access.

The conception of a dual or even a multiple personality is worked out in
a series of papers by Mr. F. W. H. Myers[1]