f mental mechanisms
created by dissociation.

Hypnotism represents an extreme but temporary form of dissociation of
the memories, artificially produced. Fascination and abstraction
(absent-mindedness) are milder forms of the same phenomena with this
difference, that they occur "in nature" and without artificial
stimulation.

A more permanent dissociation is represented in moods. The memories
which connect themselves with moods are invariably such as will support
the dominant emotion. At the same time memories which tend in any way to
modify the prevailing tone of the mood are spontaneously suppressed.

It is a familiar fact that persons whose occupations or whose mode of
life brings them habitually into different worlds, so that the
experiences in one have little or nothing in common with those of the
other, inevitably develop something akin to a dual personality. The
business man, for example, is one person in the city and another at his
home in the suburbs.

The most striking and instructive instances of dissociation, however,
are the cases of dual or multiple personality in which the same
individual lives successively or simultaneously two separate lives, each
of which is wholly oblivious of the other. The classic instance of this
kind is the case of the Rev. Ansel Bourne reported by William James in
his _Principles of Psychology_. Ansel Bourne was an itinerant preacher
living at Greene, Rhode Island. On January 19, 1887, he drew $551.00
from a bank in Providence and entered a Pawtucket horse car and
disappeared. He was advertised as missing, foul play being suspected.

On the morning of March 24, at Norristown, Pennsylvania, a man calling
himself A. J. Brown awoke in a fright and called on the people of the
house to tell him who he was. Later he said he was Ansel Bourne. Nothing
was known of him in Norristown except that six weeks before he had
rented a small shop, stocked it with stationery, confectionery, and
other small articles, and was carrying on a quiet trade "without seeming
to anyone unnatural or eccentric." At first it was thought he was
insane, but his story was confirmed and he was returned to his home. It
was then deemed that he had lost all memory of the period which had
elapsed since he boarded the Pawtucket car. What he had done or where he
had been between the time he left Providence and arrived in Norristown,
no one had the slightest information.

In 1890 he was induced by William James to s