194. What is temperament?
195. What is a passion?
§ [21]. Complications of Willing
We have shown in an earlier chapter how voluntary—that is, foreseeing—actions develop out of instincts. Sensations result from the instinctive action, are associated with those other impressions which called forth the instinctive response, can then be reproduced by them, and can themselves produce the action. When an action is thus foreseen, it is called voluntary. Such simple voluntary actions are then combined into complicated groups and chain-like progressions. The conscious result of the first movement calls up the idea of a further movement, its execution that of a third movement, and so on. Serial activities of this kind often go on for a long time; for example, walking, eating, dressing, writing, sewing, rowing. As experience of the relations between the external things and practice in the performance advance, such serial actions become more and more perfect in several respects. Their conscious anticipation is more and more extended, so that they may be adapted to very remote consequences, the occurrence of which is not expected until days or weeks afterward. They are more and more refined in that they adjust themselves accurately in direction, speed, and force to the special circumstances of each case. They are performed in less time and more economically; all detail movements which are either wrong or merely superfluous come to be entirely omitted.
That the conscious processes in voluntary movements tend toward simplification has been mentioned in [§ 10]. A whole series of movements, which was originally performed by each movement being consciously anticipated in order, is now performed without further consciousness as soon as the series has once begun. One fact, however, is highly interesting in this connection because it shows how the several movements of the series are actually caused. Although consciousness of all those anticipations of the movements is no longer required, the physiological sensory functions must run their course in the normal order or disturbances occur in the movement. This may be demonstrated in an animal by cutting all the sensory nerves of a limb, but carefully leaving all the motor nerves intact. The limb nevertheless appears paralyzed. A similar case in man has been described by Strümpell. A workman received a knife wound in the spinal cord. Complete recovery occurred, with the exception that the right hand and lower arm remained perfectly anesthetic: no kind of cutaneous or organic sensation was any longer perceived. The muscles of the hand and arm functioned almost normally. But movements, even very moderately complicated, could no longer be performed unless the man saw his hand and its movement. The illustration (figure 18) shows his behavior when requested to form a ring with his thumb and index finger. He could do this fairly well when permitted to look at his hand. Otherwise it was impossible, in spite of his will and the muscular capacity to perform this action. We see, then, that the peripheral impressions are necessary to bring about the several partial movements in this case of acquired serial activity, although these impressions have long ceased to become conscious whenever the act is done.
When we anticipate a final result of an extended series of movements, it frequently happens that the movement which directly leads to that result is, for one cause or other, not immediately possible. Imagine that a person for the first time sees some one pulling a cork from a bottle, pouring some of the contents into a glass, and inviting him to drink. Seeing the bottle again calls up in his mind the idea of a delicious beverage and the movement of drinking. But drinking is impossible, for there is no glass, and the bottle is corked. In such a case the idea of the result, which because of its importance is being kept constantly in mind, unrolls the total series of ideas in the reverse order. It calls up first the thoughts directly preceding the final result, then the thoughts preceding these, and so on, until an idea is reached which can be realized by a movement. In our example the person becomes conscious of the idea of pulling the cork, of the corkscrew used for this purpose, the place where the corkscrew was found hanging, the movements of preparing it for the task, and a similar set of ideas for the glass; and he thus becomes able to carry out the whole series of movements which result in the taste of the beverage.
QUESTIONS
196. Give examples of serial activities of the foreseeing kind.