Chapter II: The Special Facts of Consciousness (3)

We can will to do only that which in its elements we have previously done by instinct. If we do not know how a movement feels when we perform it, of course we cannot bring it about by way of our consciousness, that is, by our will. Children have as much command of speech as they have acquired by instinctively producing speech sounds in response to accidental stimulations. This instinctive production occurs usually rather late in the case of certain sounds, as _k_, _r_, _sh_; and accordingly, in spite of all special efforts on the part of the parents, children learn to produce those sounds only at that late time. We presuppose, of course, that they are not deaf. For in deaf children the speech sounds instinctively produced do not enter into an association with the kinesthetic sensations and therefore cannot be voluntarily reproduced; that is, the children remain dumb. Many a grown person remembers that all his attempts at learning the pronunciation of a certain sound in foreign speech (take for example the gutteral German _r_, or the German _ch_, or the French nasal sounds) were in vain until by a mere accident, instinctively, he pronounced that very sound. After that he had command of it.

This interweaving of the instinctive reactions of the body with conscious life is of the greatest practical significance. However well adapted the inherited reflexes may be to the purpose of keeping the young animal alive, they are very insufficient in meeting the ever growing complications of life. And they are not perfect even in the beginning. A reflex is the response to a present and direct impression upon the organism; but very similar impressions may come from things of different properties. Poisonous substances often look and taste like articles of food. The enemy assumes the attitude of a friend welcoming you. Reflex action is powerless to give the organism the protection needed in such cases. Instinct is easily deceived. But as soon as the harmful consequences impress themselves upon the organism, the instinct is modified, and in the future these consequences will be avoided. The instincts are ready-made institutions intended to be applied to average conditions. Their readiness and completeness is in so far of inestimable advantage to the organism. If it had to learn everything necessary for life, it could not survive. But for the manifold deviations of the external world from the average no provision can be made in this manner.

The variation of the organism’s response is made possible by the existence of higher nerve centers, that is, of connecting neurons of a higher order, more remote from the sensory and motor points of the body. Let us imagine the proverbial reaction of a child to the sight of a flame, and discuss the successive stages of development by the help of figure 15. (1) The visual stimulation starts a nervous process from _s_{1}_, which passes through the bulb and spinal cord into the muscles of the arm at _m_{1}_. A small part of the current may branch off at _a_ and, instead of passing down towards _b_, take the direction of _v_. But the resistance in this direction is for the present so high that only an insignificant part of the process can take this way, and so no corresponding motor response is noticeable.

(2) While all this is still going on and the child’s arm is still moving forward, the heat of the flame acts as a pain stimulus at _s_{2}_. The nervous process produced passes over _c_ and _d_ to the muscles at _m_{2}_, whose contraction results in the arm’s being pulled back. This results in a third stimulation at _s_{3}_, which we need not trace farther here. But not the whole of the nervous process passes from _c_ down to _d_. A part of it, of considerable absolute magnitude because of the intensity of stimulation, passes from _c_ up to _p_ and thence over _k_ down to _d_ and finally also into _m_{2}_. This process going from _p_ to _k_, according to a general law of nervous activity, tends to attract other, weaker nervous processes, if the neuron connections make this possible. Consequently the nervous process from _s_{1}_ to _a_ is now turned mostly into the path _a-v-p_ and only an insignificant part of it continues to go from _a_ towards _b_. The consequence is that the resistance of the path _a-v-p-k-d_ is soon reduced to less than the resistance of the path _a-b_. The great significance of this fact becomes clear in the third stage of development.

(3) At some later time the flame again acts as a visual stimulus. But now, because of the change of resistance just explained, the nervous process takes for the most part the path over _a-v-p-k-d_, and the reaction follows at _m_{2}_ instead of at _m_{1}_. The child has learned to avoid the flame. The child, when seeing the flame, is conscious of the pain, as imagery, without having to receive the actual stimulation at _s_{2}_.

Thus the inflexible regularity of reaction gives place to another type of reaction, an adaptation, not only to those conditions which at the time make their impression upon the organism, but also to those conditions which are mere future possibilities. The experience of the past guides the organism into the future.

QUESTIONS

117. What is the twofold connection into which instinctive movement
enters with consciousness?

118. Why is the movement of a billiard ball often accompanied by
movements of the players or spectators?

119. What is a voluntary movement?

120. In what manner is will dependent on instinct?

121. Why do deaf children not acquire speech? Can they be taught to
speak?

122. Why is the acquisition of foreign speech sounds by grown
people often so slow?

123. What is the advantage to the organism of voluntary over
instinctive action?

124. Can you describe the three stages of nervous development
illustrating the proverb “A burnt child fears the fire”?