ne.
A cat which is put into a cage of which it has had experience behaves
differently from the way in which it behaved at first. We can easily
invent hypotheses, which are quite likely to be true, as to connections
in the brain caused by past experience, and themselves causing the
different response. But the observable fact is that the stimulus of
being in the cage produces differing results with repetition, and that
the ascertainable cause of the cat's behaviour is not merely the cage
and its own ascertainable organization, but also its past history
in regard to the cage. From our present point of view, the matter is
independent of the question whether the cat's behaviour is due to some
mental fact called "knowledge," or displays a merely bodily habit. Our
habitual knowledge is not always in our minds, but is called up by the
appropriate stimuli. If we are asked "What is the capital of France?"
we answer "Paris," because of past experience; the past experience is as
essential as the present question in the causation of our response. Thus
all our habitual knowledge consists of acquired habits, and comes under
the head of mnemic phenomena.

(b) IMAGES.--I shall have much to say about images in a later lecture;
for the present I am merely concerned with them in so far as they are
"copies" of past sensations. When you hear New York spoken of, some
image probably comes into your mind, either of the place itself (if you
have been there), or of some picture of it (if you have not). The image
is due to your past experience, as well as to the present stimulus of
the words "New York." Similarly, the images you have in dreams are
all dependent upon your past experience, as well as upon the present
stimulus to dreaming. It is generally believed that all images, in their
simpler parts, are copies of sensations; if so, their mnemic character
is evident. This is important, not only on its own account, but also
because, as we shall see later, images play an essential part in what is
called "thinking."

(c) ASSOCIATION.--The broad fact of association, on the mental side, is
that when we experience something which we have experienced before,
it tends to call up the context of the former experience. The smell of
peat-smoke recalling a former scene is an instance which we discussed a
moment ago. This is obviously a mnemic phenomenon. There is also a more
purely physical association, which is indistinguishable from physical
habit. This i