ding of the words "this morning" is not the habit of
associating the words with a fixed object, but the habit of associating
them with something having a fixed time-relation to our present. This
morning has, to-day, the same time-relation to my present that yesterday
morning had yesterday. In order to understand the phrase "this morning"
it is necessary that we should have a way of feeling time-intervals,
and that this feeling should give what is constant in the meaning of the
words "this morning." This appreciation of time-intervals is, however,
obviously a product of memory, not a presupposition of it. It will be
better, therefore, if we wish to analyse the causation of memory by
something not presupposing memory, to take some other instance than that
of a question about "this morning."

Let us take the case of coming into a familiar room where something has
been changed--say a new picture hung on the wall. We may at first
have only a sense that SOMETHING is unfamiliar, but presently we shall
remember, and say "that picture was not on the wall before." In order to
make the case definite, we will suppose that we were only in the room
on one former occasion. In this case it seems fairly clear what happens.
The other objects in the room are associated, through the former
occasion, with a blank space of wall where now there is a picture. They
call up an image of a blank wall, which clashes with perception of the
picture. The image is associated with the belief-feeling which we found
to be distinctive of memory, since it can neither be abolished nor
harmonized with perception. If the room had remained unchanged, we
might have had only the feeling of familiarity without the definite
remembering; it is the change that drives us from the present to memory
of the past.

We may generalize this instance so as to cover the causes of many
memories. Some present feature of the environment is associated, through
past experiences, with something now absent; this absent something comes
before us as an image, and is contrasted with present sensation. In
cases of this sort, habit (or association) explains why the present
feature of the environment brings up the memory-image, but it does
not explain the memory-belief. Perhaps a more complete analysis could
explain the memory-belief also on lines of association and habit, but
the causes of beliefs are obscure, and we cannot investigate them
yet. For the present we must content ourselves