n of self. This is our
condition on awaking from a perfectly forgotten period of sleep, or from
a perfectly unconscious state (if such is possible) when induced by
anaesthetics. Such gaps are, as we have seen, easily filled up, and the
sense of identity restored by a kind of retrospective "skipping." On the
other hand, the confusion which arises from too great and violent a
transformation of our _remembered_ experiences is much less easily
corrected. As long as the recollection of the old feelings remains, and
with this the sense of violent contrast between the old and the new
ones, so long will the illusion of two sundered selves tend to recur.

The full development of this process of imaginative fission or cleavage
of self is to be met with in mental disease. The beginnings of such
disease, accompanied as they commonly are with disturbances of bodily
sensations and the recurring emotions, illustrate in a very interesting
way the dependence of the recognition of self on a certain degree of
uniformity in the contents of consciousness. The patient, when first
aware of these changes, is perplexed, and often regards the new feelings
as making up another self, a foreign _Tu_, as distinguished from the
familiar _Ego_. And sometimes he expresses the relation between the old
and the new self in fantastic ways, as when he imagines the former to be
under the power of some foreign personality.

When the change is complete, the patient is apt to think of his former
self as detached from his present, and of his previous life as a kind of
unreal dream; and this fading away of the past into shadowy unreal forms
has, as its result, a curious aberration in the sense of time. Thus, it
is said that a patient, after being in an asylum only one day, will
declare that he has been there a year, five years, and even ten
years.[135] This confusion as to self naturally becomes the
starting-point of illusions of perception; the transformation of self
seeming to require as its logical correlative (for there is a crude
logic even in mental disease) a transformation of the environment. When
the disease is fully developed under the particular form of monomania,
the recollection of the former normal self commonly disappears
altogether, or fades away into a dim image of some perfectly separate
personality. A new ego is now fully substituted for the old. In other
and more violent forms of disease (dementia) the power of connecting the
past and present