ed by the movement of imagination in going
back to it from the present. And this is the same thing as to say that
it depends on our retrospective sense of the intervening space. That is
to say, the sense of distance in time, as in space, is the recognition
of a term to a movement. And just as the distance of an object will seem
greater when there are many intervening objects affording points of
measurement, than when there are none (as on the uniform surface of the
sea), so the distance of an event will vary with the number of
recognized intervening points.

The appreciation of the distance of an event in time does not, however,
wholly depend on the character of this movement of imagination. Just as
the apparent distance of a visible object depends _inter alia_ on the
distinctness of the retinal impression, so the apparent temporal
remoteness of a past event depends in part on the degree of intensity
and clearness of the mnemonic image. This is seen even in the case of
those images which we are able distinctly to localize in the
time-perspective. For a series of exciting experiences intervening
between the present and a past event appears not only _directly_ to add
to our sense of distance by constituting an apparently long interval,
but _indirectly_ to add to it by giving an unusual degree of faintness
to the recalled image. An event preceding some unusually stirring series
of experiences gets thrust out of consciousness by the very engrossing
nature of the new experiences, and so tends to grow more faint and
ghost-like than it would otherwise have done.

The full force of this circumstance is best seen in the fact that a very
recent event, bringing with it a deep mental shock and a rapid stirring
of wide tracts of feeling and thought, may get to look old in a
marvellously short space of time. An announcement of the loss of a dear
friend, when sudden and deeply agitating, will seem remote even after an
hour of such intense emotional experience. And the same twofold
consideration probably explains the well-known fact that a year seems
much shorter to the adult than to the child. The novel and comparatively
exciting impressions of childhood tend to fill out time in retrospect,
and also to throw back remote events into a dimly discernible region.

Now, this same circumstance, the degree of vividness or of faintness of
the mnemonic image, is that which determines our idea of distance when
the character of the intervening