The Principles of Psychology, Volume 2 (of 2)

Are almost colorless;

Have lively coloration;

Are continuously enduring;

Incessantly disappear, and have to

be renewed by an effort of will.

At last even this fails to revive them.

Cannot be voluntarily changed.

Can be exchanged at will for others.

Are exact copies of originals.

Cannot violate the necessary laws of

appearance of their originals—e.g.,

a man cannot be imagined from

in front and behind at once. The

imagination must walk round him,

so to speak;

Are more easily got with shut than

Are more easily had with open than

with open eyes;

with shut eyes;

Seem to move when the head or eyes

Need not follow movements of head

move;

or eyes.

The field within which they appear

The field is extensive in three

(with closed eyes) is dark, contracted,

dimensions, and objects can be

flat, close to the eyes, in

imagined in it above or behind

front, and the images have no

almost as easily as in front.

perspective;

The attention seems directed forwards

In imagining, the attention feels as

towards the sense-organ, in

if drawn backwards towards the

observing after-images.

brain.

Finally, Fechner speaks of the impossibility of attending to both after-images and imagination-images at once, even when they are of the same object and might be expected to combine. All these differences are true of Fechner; but many of them would be untrue of other persons. I quote them as a type of observation which any reader with sufficient patience may repeat. To them may be added, as a universal proposition, that after-images seem larger if we project them on a distant screen, and smaller if we project them on a near one, whilst no such change takes place in mental pictures.

[56] [I am myself a good draughtsman, and have a very lively interest in pictures, statues, architecture and decoration, and a keen sensibility to artistic effects. But I am an extremely poor visualizer, and find myself often unable to reproduce in my mind's eye pictures which I have most carefully examined.—W. J.]