Dominant Ileas. 795 



founded, and gradually subvert such ideas and change the actions to 

 which they lead ; others show new relations and possibilities of action 

 never before dreamed of. The invention of the compass enabled mari- 

 ners to sail out of sight of land, which before they were afraid to do. 

 The invention of the telescope led to the proof that the world was not 

 the center of the universe, and thus undermined the notion of its rela- 

 tive importance, and consequently of the importance of the human race, 

 its most valuable appurtenance. Thus, the dominant ideas are subject 

 to slow evolution and modification by the natural forces of the environ- 

 ment, just as the Gods are subject to the Fates. 



The dominance of a general idea often leads to individual delusion. 

 When witchcraft was a common belief, individuals were often found to 

 fancy themselves bewitched, while it was no uncommon thing for a 

 woman to confess herself a witch. In times of religious excitement, 

 individuals often imagined themselves to receive impressions from a 

 supernatural agenc} T , when in reality they are only under the influence 

 of a dominant idea, become highly personal and emotional. 



When dominant ideas become emotional, they may become epidemic, 

 and affect large numbers of persons belonging to a particular commun- 

 ity or society. There are many examples of emotional epidemics aris- 

 ing most frequently from religious excitement, in which the excited emo- 

 tions have found expression in convulsions, dancing, and various phan- 

 tastic physical performances. The "dancing plague " is a form of con- 

 vulsion something like St. Vitus' dance, which has occurred in various 

 parts of the world, under different names, as Tarantismus in Southern 

 Italy and Northern Africa, and Tigretier in Abyssinia. In Scotland 

 they have had what the}*- call Leaping Ague, which results from an ' < irre- 

 sistible propensity to dance, tumble, and move about in a fantastic 

 manner" with extraordinary energy. Almost all nervous diseases are 

 more or less due to an idea, which is proved by the fact that they can 

 often be cured by a counteracting idea. Thus it is related that a factory 

 girl in a factory in Lancashire was thrown into fits by a mischievous 

 fellow who put a mouse down inside of her clothing. The sight of the 

 spasms caused an epidemic which spread among the other girls, till 

 scores of them had fits day after day. They got a notion that they 

 were caused by the emanations from a bale of cotton. This was 

 shown to be a mere whim. The cure was finall} r effected by shocks of 

 electricity accompanied by the assurance of its efficacy on the part of 

 the medical man. It was simply diversion from a dominant idea and 

 substitution of another for it. 



Fits of hysteria once got to be epidemic among the Irish girls in a 

 hospital at Bristol, and were cured by threats of a shower bath to all that 

 indulged them. In a certain nunnery in Europe, one of the nuns got 



