PSYCHIC ADAPTATION 109 



the other hand, ceased to be healthy, from want of 

 nourishment or some irregularity shown by a loss 

 of strength, a want of balance, degeneration made 

 its appearance, and with it all human miseries ; the 

 brain lost its completeness, and, unable duly to 

 repair its strength, ceased to be susceptible to the 

 external stimulus, separating itself from the real 

 and leading to the era of visionaries, as happened 

 during the long dark period of the Middle Ages. 



" The work of human intelligence," says Taine, 

 " like the work of Nature, is only to be explained 

 through the medium." 



And in fact, when the medium improves, men 

 become more healthy, the conditions necessary for 

 cerebral activity are realised, a better contact is 

 established between Nature and the brain, and a 

 phenomenon such as electrical induction takes place, 

 and hence the astounding impulse manifested by 

 nations under these conditions. The human brain 

 when sound has forces still more wonderful than 

 the lately discovered power of radio-activity ; the 

 intelligence must possess some of these wonderful 

 properties by which phenomena are registered in a 

 series uniform with that of the natural laws, and 

 by means of which, when the substance on which 

 the intelligence is based is kept in a healthy state, 

 the forces of universal mechanics are diffused 

 throughout the human brain, in order to impart to 



