to time,
auditory, kinesthetic, tactile and olfactory images. So that the
"mixed type" is the only real type, the extreme visualist or audile,
etc., being exceptional and not typical.

{371}

Limitations of Imagery

Recalled sensations are commonly inferior to their originals, both in
the enjoyment they afford and in the use that can be made of them.
They are likely to be inferior in several respects.

(1) An image has usually less color, or tone--less body, realism and
full sensory quality--than a sensation aroused by its appropriate
peripheral stimulus. While you may be able to call up a fairly good
image of your absent friend's face, the actual presence of your friend
would be more satisfactory, just as a sensory experience. You may be
able to run over a piece of music "in your head", and if your auditory
imagery is strong you may even run over an orchestral piece, and get
the tone quality of the various instruments; but, after all, such a
mental concert is an imperfect substitute for a real orchestra. You
enjoy a real whiff of the sea more than the best olfactory image you
can summon. There is something lacking in these recalled sensations,
and the trouble seems to be that they are not sensations enough; they
lack sensory body.

(2) Images are apt to be sketchy and lacking in detail, and also
narrow and lacking in background.

(3) Images are apt to be unsteady and fleeting, as compared with
actual sensations. Where the peripheral stimulus, continuing, keeps
the sensation going, the substitute stimulus that recalls a sensation
is not so effective in this respect, any more than in giving body and
detail. In all these respects, an image is less enjoyable and
satisfying than an actual sensation.

(4) On the more practical side, images are inferior to the actual
presence of an object, in that we cannot utilize the image as a source
of new information. {372} We _cannot observe facts_ in the image of a
thing that we have not observed in the actual presence of the thing.

At one of the universities, there is a beautiful library building,
with a row of fine pillars across the front, and the students pass
this building every day and enjoy looking at it. It has long been a
favorite experiment in the psychology classes at that university to
have the students call up an image of the library, and to have them
state how clear their image is, how complete and how vivid. Then they
are asked to count the pillars from their