ver, that the feeling which
prompts to flight or serves to deter from harm's way might be useful. It
is plain that there is an advantage in the tense muscle, the set teeth,
the held breath, and the quickened pulse which accompany the emotion of
anger, and also in the feeling of anger itself, which prompts to the
conflict. But even if we are not able in every case to determine at this
day why all the instinctive responses and their correlate of feeling
were the best for the life of the race, we may be sure that such was the
case; for Nature is inexorable in her dictates that only that shall
persist which has proved serviceable in the largest number of cases.

An interesting question arises at this point as to why we feel emotion
accompanying some of our motor responses, and not others. Perceptions
are crowding in upon us hour after hour; memory, thought, and
imagination are in constant play; and a continuous motor discharge
results each moment in physical expressions great or small. Yet, in
spite of these facts, feeling which is strong enough to rise to an
emotion is only an occasional thing. If emotion accompanies any form of
physical expression, why not all? Let us see whether we can discover any
reason. One day I saw a boy leading a dog along the street. All at once
the dog slipped the string over its head and ran away. The boy stood
looking after the dog for a moment, and then burst into a fit of rage.
What all had happened? The moment before the dog broke away everything
was running smoothly in the experience of the boy. There was no
obstruction to his thought or his plans. Then in an instant the
situation changes. The smooth flow of experience is checked and baffled.
The discharge of nerve currents which meant thought, plans, action, is
blocked. A crisis has arisen which requires readjustment. The nerve
currents must flow in new directions, giving new thought, new plans, new
activities--the dog must be recaptured. It is in connection with this
damming up of nerve currents from following their wonted channels that
the emotion emerges. Or, putting it into mental terms, the emotion
occurs when the ordinary current of our thought is violently
disturbed--when we meet with some crisis which necessitates a
readjustment of our thought relations and plans, either temporarily or
permanently.

THE DURATION OF AN EMOTION.--If the required readjustment is but
temporary, then the emotion is short-lived, while if the readjustmen