108 MENTAL OPERATIONS IN RELATION TO TIME. 



common and natural connexions. The thoughts in 

 such persons are inconsecutive and fragmentary ; and 

 the mind, working dreamily within itself, takes little 

 heed of what comes from without, even of the responses 

 of common conversation. Some of these cases, of which 

 I have seen many, tend to more serious mental aberra- 

 tion, forming one of the several links with insanity 

 under the multiform shapes which mental maladies 

 assume. All these abnormal states form a large school 

 for study, in reference to the successions and correla- 

 tions of mental acts of which I have now been speaking. 

 The idiot and the maniac interpret to us many of the 

 conditions of the soundest and most capacious minds. 1 



How different, again, are the modes of thinking of 

 the same mind at different times ! I have already 

 alluded to this ; but everyone who cares to do so may 

 collect illustrations replete with interest from his own 

 consciousness. Take the instance of that sudden 

 quickening and elevation of mental power which is 

 obtained when the faculties are strongly evoked by 

 occasion or necessity, as in public speaking, in close 

 and cogent argument, in the repartee of wit. The case 

 of the orator is perhaps the most striking. As he 

 warms with his theme ' ubi res agitur, et vera dimi- 

 catio est' thoughts, memories, images, and words 

 crowd upon him for utterance with unwonted rapidity, 

 and for a time his mind seems raised to a higher level 

 of genius and power. Conversely, the faculties which 



1 When Roger North describes his brother Dr. John North as ' the 

 most intense and passionate thinker who ever lived and was in his right 

 mind,' he is using phrases which do not go beyond the frequent reality. 



