264 PSYCHOLOGY. 



On the Command or Presence of Mind. 



Every part that acts in consequence of sensation must be at the com- 

 mand of the will, for the will is formed out of sensation. The iris of 

 the eye contracts immediately upon light being thrown upon an eye 

 sensible to that stimulus, that is an action arising immediately from such 

 sensibility. It is possible that we might not be able to imitate it by 

 the will. But as the iris also contracts and dilates upon bodies being- 

 placed near or far off [the eye], we can, in the dark, contract our iris 

 by putting the eye into that form which it assumes when it is viewing 

 a near body ' ; and, on the contrary, we can make the iris dilate in the 

 light [by putting the eye into that form], as when viewing an object at 

 a distance. 



As sensations form the will, so can the will attend to any sensation. 

 The will can attend to one sensation out of many. In many sounds the 

 ear can, by the will, follow one of them singly. 



The mind is formed by habit, as the body is. The body may be made 

 to endure many things, as fatigue, heat, cold, ifcc, without inconvenience 

 to itself, or without making the mind sensible of it. The mind may be 

 made to endure almost anything, and it may be so humoured as hardly 

 to bear any inconvenience. 



It is curious to see how much the mind, abstracted from the body, is 

 similar to the body influenced by the mind. A man, when anxious to 

 do a thing well, and more especially if another is in some degree con- 

 cerned, seldom does it well ; and, the more he endeavours, the worse he 

 performs it ; in like manner, if a man does not readily remember a 

 thing, and becomes anxious to remember it, he will not in the least 

 remember it, excepting some relative circumstance or connexion brings 

 the tiring into his mind. But if he can get naturally into the train 

 of thinking that leads to the thing, without art or intention, he will 

 immediately remember it. 



Thus if a man were made to repeat anything he did not perfectly 

 remember, he would probably forget how to begin. When he had begun, 

 he might go on ; but if he forgot any part, he would not find it out by 

 the mind endeavouring to recollect it. He might go on if he began 

 again ; and would go on if he had no fears, doubts, or even thoughts 

 in his mind, of the possibility of forgetting any part. If he could do it so 

 carelessly as not to be conscious he was doing it at all, he most probably 

 would go through the whole without interruption. So much is the train 

 of habitual thinking interrupted by the immediate interference of the 

 will, producing a state of mind which adds to the interruption. 



1 [By the act of looking intently upon an ideally near body.] 



