cases than others. For example,
in an appeal to the eye, rectangular shape in proportion of three to five,
that is to say, three units of measurement wide by five units of
measurement long is more likely to attract favorable attention than a
square. Similarly, any object in motion or having the illusion of motion,
is more likely to attract favorable attention than an object at rest.
Black letters upon a white background attract more favorable attention
than white letters upon a black background. Many such psychological
problems have been worked out. They are valuable, but they have no place
in this work, since our task here is not to deal with averages, but rather
with variations in individuals--how to discern them and how to deal with
them.

INTEREST

In a similar way, psychologists have determined that the average
individual more quickly becomes interested in that which he can understand
than in that which he cannot understand, in that which appeals to
something in his own experience than in that which has no such appeal, in
that which appeals to his tastes and his feelings than in that which
appeals to his judgment. These are rules applicable to the average, but
they are very general and are of little use to you unless you add to them
specific knowledge of every individual whom you wish to persuade.

DESIRE

Desire, as you will see by the terms of the law of sale, is merely
interest intensified. Desire is the main spring of action. It is the real
force of every motive. Contradictory as it may seem at first sight, people
always do what they want to do even when they act most reluctantly. Their
action is inspired by a desire to escape what they believe to be the
certain penalty of inaction or of contrary action. The boy who slowly
approaches his father to receive a promised whipping, does so because he
wants to. And he wants to because he knows he will be whipped so much
harder if he runs away. Desire is, therefore, the great citadel toward
which all of the campaign of the persuader must be directed. Given a
powerful enough desire, decision and action follow as a matter of course.

Psychologists have determined that imagination is the most powerful mental
stimulus to desire. Imagination presents to the mind, as it were, a more
or less vivid mental picture of the individual enjoying the gratification
of his desire--be it physical, intellectual, or spiritual. The longer this
picture remains in the mind, the more viv