484 THE BRAIN. 



proper relation between them, and of originating in consequence an in- 

 telligent volitional act. 



The cerebral hemispheres as a whole are therefore evidently the 

 centres in which the nervous mechanism of mental action is accom- 

 plished. The mental endowments which are concerned in the manifesta- 

 tions of the intelligence are mainly the memory, the reason and the 

 judgment. 



Memory is the simplest and most essential of these faculties for the 

 due performance of intelligent acts. The recollection of names, and of 

 the objects to which they belong, is indispensable even to the use of 

 articulate language ; and a deficiency of memory seems often to be the 

 immediate condition upon which the incapacity of idiotic children to 

 talk depends. It is also constantly essential in the ordinary occupations 

 of life, in enabling us to retain past impressions as a guide for imme- 

 diate or future acts. 



The reason may be considered as the faculty by which we appreciate 

 the character of the nervous impressions received, and are enabled to 

 refer them to their external source. This is quite different from the 

 simple power of perception, which continues, as experiment has demon- 

 strated, after the removal of the cerebral hemispheres. The mental 

 action which is excited by an impression coming from without is one 

 which transfers the attention from the internal sensation to its external 

 source ; and when this action is prompt and effectual, we at once acquire 

 an idea of whence the impression originated and what is its significance. 

 The perfection of this quality consists in the certainty with which it 

 appreciates the relation between an effect and its cause, and the relative 

 importance of different phenomena. This capacity is deficient or absent 

 in idiots, and consequently they cannot avoid dangers or provide for 

 their necessities. For the same reason it is useless to punish an idiot, 

 because, although he may feel the pain inflicted, he does not refer it as 

 a consequence to any previous action of his own. A deficiency of the 

 same quality in the insane, or in those in whom it is naturally imper- 

 fect, produces a want of power to comprehend the importance and connec- 

 tion of different events. They are said to be " unreasonable," because 

 they expect results which are unlikely to follow from certain causes, 

 and because they assume the existence of causes which are not realty 

 indicated by the results. 



The judgment is the faculty by which the appropriate means are 

 selected for the accomplishment of a particular end. Its exercise re- 

 quires the existence of reason and memory, which supply the necessary 

 conditions upon which it is based ; but its own action is one which 

 looks to the future rather than to the past. An individual in whom the 

 judgment is well developed employs, under the guidance of experience, 

 means which are well adapted to attain the end he has in view ; one 

 who is deficient in this respect resorts to means which are insufficient 

 or inappropriate, and is consequent!}' unsuccessful. Whether the act 

 performed in this manner be a simple mechanical operation, like that of 





