certain Processes of the Human Understanding. 83 



coming virtually single conceptions are executed by single movements. One 

 act of volition can direct the most complicated movement when it is once thus 

 conceived. And it is a very remarkable and highly confirmatory fact, that the 

 slightest attempt to direct the attention to any of the separate components or 

 signs, would instantly disconcert the most practised skill. This Mr. Stewart 

 would have seen and profited by seeing, had he not selected examples of which 

 the component acts are not necessarily simultaneous. A performer on some kind 

 of instrument requiring a succession of uncompounded movements, may un- 

 doubtedly, by playing more slowly, attend to his separate touches, but then he is 

 not a case in point : for that species of acceleration of the mental processes 

 which can be actually observed, is not that for which Mr. Stewart would contend. 

 The point here to be established, is not that the mind may not operate with any 

 imaginable velocity, but that the assumption of an acceleration so great as to es- 

 cape all consciousness, is unnecessary for certain purposes, and a departure from 

 an observable and well known process. It is one thing to assert that the mind 

 can by distinct steps follow and regulate certain rapid changes of motion, and 

 another to assume that this process may become so rapid, as to be impossible for 

 the apprehension to follow it distinctly. The real difficulty which I shall have to 

 surmount is this, that there appears in this case, and some others, to be two dis- 

 tinct trains of thought going on. I mean, further on, to show that this is but 

 apparent, and I shall at the same time show that Mr. Stewart's assumption vastly 

 aggravates this difficulty. 



A curious instance of the effect of separate attentions and volitions in cases 

 of complex action is not very uncommon. When a person of a very anxious 

 temper is called on for an exhibition of skill in some act which requires very 

 complex acts of mind, it sometimes occurs, that extreme anxiety to succeed forces 

 the attention from the common process, as here described, to an intimate notice 

 of the separate acts of the combination : and the links of complex volition are 

 thus broken, so that embarrassed movements follow. The best illustration of 

 this will occur farther on. 



This last circumstance is most frequently observable in that extensive class of 

 acts, which, in popular phrase, we call mechanical. They are, indeed, nearly de- 

 cisive against Mr. Stewart; for, while they consist, for the most part, of complex 

 movements, the separate acts of which they are framed have never been recognized 



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