experiences produces no appreciable
effect.[124] This is most strikingly illustrated in those imperfect
kinds of recollection in which we are unable to definitely localize the
mnemonic image. To the consideration of these we will now turn.

B. _Indefinite Localization._

Speaking roughly and generally, we may say that the vividness of an
image of memory decreases in proportion as the distance of the event
increases. And this is the rule which we unconsciously apply in
determining distance in time. Nevertheless, this rule gives us by no
means an infallible criterion of distance. The very fact that different
people so often dispute about the dates and the order of past events
experienced in common, shows pretty plainly that images of the same age
tend to arise in the mind with very unequal degrees of vividness.

Sometimes pictures of very remote incidents may suddenly present
themselves to our minds with a singular degree of brightness and force.
And when this is the case, there is a disposition to think of them as
near. If the relations of the event to other events preceding and
succeeding it are not remembered, this momentary illusion will persist.
We have all heard persons exclaim, "It seems only yesterday," under the
sense of nearness which accompanies a recollection of a remote event
when vividly excited. The most familiar instance of such lively
reproduction is the feeling which we experience on revisiting the scene
of some memorable event. At such a time the past may return with
something of the insistence of a present perceived reality. In passing
from place to place, in talking with others, and in reading, we are
liable to the sudden return by hidden paths of association of images of
incidents that had long seemed forgotten, and when they thus start up
fresh and vigorous, away from their proper surroundings, they invariably
induce a feeling of the propinquity of the events.

In many cases we cannot say why these particular images, long buried in
oblivion, should thus suddenly regain so much vitality. There seems,
indeed, to be almost as much that is arbitrary and capricious in the
selection by memory of its vivid images as in the selection of its
images as a whole; and, this being so, it is plain that we are greatly
exposed to the risk of illusion from this source.

There is an opposite effect in the case of recent occurrences that, for
some reason or another, have left but a faint impression on the memory