IMPULSE (from Lat. impulsus, incitement, front Miff/it-re, to incite, from in, in + pcllere, to drive). The typical motive to voluntary ac tion. (See AcTIoc.) Such action is, at first, unequivocally determined: that is to say, the bodily movement follows, without hesitation or reflection, upon the formation of single. unehal 1( aged motive. As the physical organism and the mind grow in complexity. voluntary action come to be equivocally V0111111101111; there is a period of deliberation and doubt, characterized by a eon tliet of motives, some one Of which ultimately prevails. as actual motive, over the potential motives, its rivals.
The simplest form of voluntary action, that which is prompted unequivocally by one unques tioned motive, is termed in psychology impul sive action, and the motive itself an impulse. The scientific definition of the terms is reflected in popular usage: we call a character 'impulsive' acts off-hand, without balancing of alterna tives: though the ideas of waywardness and unaccountability that we associate with the idea of an 'impulsive character' do not attach to the impulse as such, but indicate rather some in twilled idiosyncrasy or defect of early training. The impulse proves, on analysis, to be a fairly stable connection of sensational and affective proc esses. If we look at it in its complete or perfect ferffi. but make its constituent processes as simple as possible, we find the following com ponents: III the perception of an object to which we are attracted or from which we are re pelled: (2) an idea of our own movement to ward or away from the object. based upon pre vious experience of actual movements; (3) an idea of the result of our movement : and (4) an affective process. the resultant of the affective colorings--oftentimes mutually opposed—of the three sensory factors. It is not difficult, in laboratory practice, to arrange for the formation of a motive in which these latter processes shall be represented on practically equal terms. In real life, although (as we said) the impulse is fairly stable in composition. we usually find a predominance of some one of the three ideas, and a subordination of the others. Thus, the idea of our own movement may recede far into the back ground of the impulsive Where it finds expression. perhaps, only in some incon spicuous fringe of organic sensation; while, as the reach of consciousness increases, the idea of object comes more and more to be lost sight of in comparison with the idea of end or result. It should be remarked, further, that the idea of our own movement, important 114 it is at a cer tain level of mental development, be con tained in the very first impulse, and cannot be of much importance for a considerable time after voluntary movements have been initiated: for, on the one hand, we must have moved before we can have an idea of our movement (so that the most primitive action of all is an 'action upon piesentation,' made in response to the simple perception of object) ; and, on the other. primi
tive movements are too vague. and too little dif ferentiated, to play the regulating and refining part that they later assume. Conversely, the complex motives that enter into con filet with one another in volitional and selective action are simply complicated impulses, in which the place of perception and idea is taken by associations of ideas or by judgments or trains of reasoning.
It is diffieult to give an illustration of an im pulsive action, for the reason that what is im pulsive in one man's consciousness need not he so in another's. The impulsive action which we select may have been repeated so often as to have degenerated into ideomotor action, or even into a secondary reflex; or it may be so unaccustomed as rather to the or volitional action. We can. however, take a fictitious ease. Suppose that a boating party, arriving at a secluded hay, are seized with the impulse to bathe. Here we have the objeet-per ception of the cool, clear water: the anticipation in idea of the free movements of diving and swimming; and the further forecast of the bodily vigor and refreshment that will ensue. All three ideas are pleasant. An opposition of affective processes might arise if the water is distinctly cold: in this case, the combined pleasantness of movement and result overcome the unpleasant ness of the object-perception. It is, however, easy to see that, for persons who always bathed when they had the opportunity. the action would be rather ideomotor than impulsive; whereas, by those members of the party who were weak swim mers. the plunge might he taken only after a geod deal of hesitaney and indecision.
Binuoonarwv. Wundt. Grundziige der phy siologist-hen Ps yehologie (Leipzig, IS93) ; id., Lee, fires on H um a n and Psychology (New York, 1896) : Schneider, Der tierische Wine (Leipzig. ISSO) : id., Der menschliehe (Berlin. 1SS2.); Titehener. Outline of Psychology (New York. IS09) ; Sully, Human Mind (Lon don, IS92) ; Breyer, Die 8eele des Kindcs (Leip zig, 1S90).