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Unformatted text preview: he individual, and to which he must react, must find an organism ready to
respond in some way or other. A sleeping man naturally does not adjust himself to danger, nor does a
paralyzed man fly. The most attractive female in the world causes no response in the very young male child
and perhaps stirs only reminiscences in the aged. Food, which causes the saliva to flow in the mouth of the
hungry, may disgust the full. Throughout life there are factors in the internal life of the organism instantly
changing one's reaction to things of physical, mental and moral significance. He talks loudest of restraint and
control who has no desire; and in satiation even the sinner sees the beauty of asceticism. There must be a
coincidence of stimulus, readiness and opportunity for the full, successful response to take place.
 A slang epigram puts it better: The time, the place, and the girl.
The simplest response to any stimulus from the outer world is the reflex act. Theoretically a reflex act is
dependent upon the interaction of a sensory surface, a sensory nerve cell, a motor nerve cell and a muscle, i.
e., a receptive apparatus and a motor apparatus in such close union that the will and intelligence play no part.
Thus if one puts his finger on a hot stove he withdraws it immediately, and such responses are present even in
the decapitated frog and human for a short time. So if light streams in on the wide-open pupil of the eye, it
contracts, grows smaller, without any effort of the will, and in fact entirely without the consciousness of the
individual. Swallowing is a series of reflexes in a row, so that food in the back part of the mouth sets a reflex
going that carries it beyond the epiglottis; another reflex carries it to the esophagus and then one reflex after
the other transports the food the rest of the way. Except for the first effort of swallowing, the rest is entirely
involuntary and even unconscious. Those readers who are interested would do well to read the work of
Pavlow on the conditioned reflex, in which the great Russian physiologist builds up all action on a basis of a
modification of the pr...
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- Spring '11