think of its general meaning and relations, the fact that it is of gold, that it is for
the purpose of keeping time, that it was a present to me, that I wear it in my left
pocket, you then have an idea of the watch. Our idea of an object is, therefore,
the general meaning of relations we ascribe to it. It should be remembered,
however, that the terms image and idea are employed rather loosely, and that
there is not yet general uniformity among writers in their use.
All Our Past Experience Potentially at Our Command.—Images may in a
certain sense take the place of percepts, and we can again experience sights,
sounds, tastes, and smells which we have known before, without having the
stimuli actually present to the senses. In this way all our past experience is
potentially available to the present. All the objects we have seen, it is potentially
possible again to see in the mind's eye without being obliged to have the objects
before us; all the sounds we have heard, all the tastes and smells and
temperatures we have experienced, we may again have presented to our minds in
the form of mental images without the various stimuli being present to the end-
organs of the senses.
Through images and ideas the total number of objects in our experience is
infinitely multiplied; for many of the things we have seen, or heard, or smelled,
or tasted, we cannot again have present to the senses, and without this power we
would never get them again. And besides this fact, it would be inconvenient to
have to go and secure afresh each sensation or percept every time we need to use
it in our thought. While habit, then, conserves our past experience on the
physical side, the image and the idea do the same thing on the mental side.
3. INDIVIDUAL DIFFERENCES IN IMAGERY
Images to Be Viewed by Introspection.—The remainder of the description of
images will be easier to understand, for each of you can know just what is meant
in every case by appealing to your own mind. I beg of you not to think that I am
presenting something new and strange, a curiosity connected with our thinking
which has been discovered by scholars who have delved more deeply into the
matter than we can hope to do. Every day—no, more than that, every hour and
every moment—these images are flitting through our minds, forming a large part
of our stream of consciousness. Let us see whether we can turn our attention
within and discover some of our images in their flight. Let us introspect.
I know of no better way to proceed than that adopted by Francis Galton years