804: Dynamic Theory. 



involving a prolonged and more exclusive concentration of the same 

 attention which in our ordinary state is directed temporarily and by 

 turns to every sensation, purpose, and action of life. It is often re- 

 marked that we cannot do or think of two things at once. This is only 

 a popular recognition of the fact, that attention is necessarily exclusive, 

 and that when it is engrossed by one stimulus, the others are in abey- 

 ance and fail for the time of producing their effect. In ordinary life we 

 are surrounded and assailed by a multitude of sensory impressions and 

 suggestive ideas projected upon us from without. The one possessing 

 the greatest tension will first control our movements, and the moment 

 its tension becomes reduced below that of some other one in waiting, 

 that one, No. 2, will control till its tension is reduced, and so on. 



We are also assailed by ideas from within, constructed in the cere- 

 brum from perceptions of former sensations. These also may at any time 

 become stimuli and in their turn absorb the attention. 



That person is the most wide-awake, versatile, and comprehensive 

 who is susceptible to the impact of the greatest number and variety of 

 these stimuli. But by reason of inherited peculiarities, strengthened or 

 modified by the habits put upon us by our environment, all of us have 

 become more susceptible to the influence of some stimuli than to that of 

 others, so that in the presence of these we are apt to be, to a great ex- 

 tent, oblivious of the existence of others. That is to say, we are in a 

 state of chronic abstraction as against those stimuli which fail to draw 

 our attention. 



For obvious reasons we never know what these are unless some one 

 tells us. In any community all the people are exposed to practically 

 the same external stimuli, and by their social habit of reminding each 

 other of those which are liable to neglect some and to impress others too 

 strongly, the tendency is to the formation of communities in which 

 the individual components are very much alike, and the stimulating 

 agencies, both external and internal, which engage their attention and 

 regulate their actions, are practically the same for all. And likewise 

 those stimuli which are habitually ignored and neglected are practically 

 the same for all. And it is obviously due to this, that we are in a con- 

 dition of practical oblivion of the fact that we are all of us in a state of 

 abstraction as to the stimuli which in numbers, and doubtless importance, 

 greatly exceed the stimuli of which we ever become conscious. 



The smaller the number of stimuli by which we are liable to be influ- 

 enced, the more concentrated and intense is the stimulation. Those 

 further stages of abstraction which go under the names of reverie, ab- 

 sence of mind, biology, hypnotism, somnambulism, and dreaming, simply 

 represent the condition after further reductions in the number of 

 stimuli ; and they exhibit their increased concentration and intensit}-. 

 They do not involve any new principle whatever. 



