knowledge. I shall speak of it as "true" memory, to distinguish it
from mere habit acquired through past experience. Before considering
true memory, it will be well to consider two things which are on the way
towards memory, namely the feeling of familiarity and recognition.

* See his "Life and Habit and Unconscious Memory."

We often feel that something in our sensible environment is familiar,
without having any definite recollection of previous occasions on which
we have seen it. We have this feeling normally in places where we have
often been before--at home, or in well-known streets. Most people and
animals find it essential to their happiness to spend a good deal of
their time in familiar surroundings, which are especially comforting
when any danger threatens. The feeling of familiarity has all sorts
of degrees, down to the stage where we dimly feel that we have seen a
person before. It is by no means always reliable; almost everybody
has at some time experienced the well-known illusion that all that is
happening now happened before at some time. There are occasions when
familiarity does not attach itself to any definite object, when there is
merely a vague feeling that SOMETHING is familiar. This is illustrated
by Turgenev's "Smoke," where the hero is long puzzled by a haunting
sense that something in his present is recalling something in his past,
and at last traces it to the smell of heliotrope. Whenever the sense of
familiarity occurs without a definite object, it leads us to search the
environment until we are satisfied that we have found the appropriate
object, which leads us to the judgment: "THIS is familiar." I think
we may regard familiarity as a definite feeling, capable of existing
without an object, but normally standing in a specific relation to some
feature of the environment, the relation being that which we express in
words by saying that the feature in question is familiar. The judgment
that what is familiar has been experienced before is a product of
reflection, and is no part of the feeling of familiarity, such as a
horse may be supposed to have when he returns to his stable. Thus
no knowledge as to the past is to be derived from the feeling of
familiarity alone.

A further stage is RECOGNITION. This may be taken in two senses,
the first when a thing not merely feels familiar, but we know it is
such-and-such. We recognize our friend Jones, we know cats and dogs
when we see them, and so o