1 Journal of Comparative Neurology. 



Special Nerves for Pain J 1 



The author's position is indicated by an early sentence of the 

 paper : " I shall endeavor to show; first, that the weight of psycholog- 

 ical evidence is strongly negative to a classification of pain with 

 sensation ; and second, that the arguments brought forward in support 

 of such classification, and of the existence of brain localization and of 

 nerve tracts and terminals for pain, are not concial." 



He objects to the association of pain with sensation ist, because 

 the former is not directly determined by special relation to the envi- 

 ronment. 



2d. Because of the relation of pain to pleasure, both being 

 emotional rather than sensational, there should be " pleasure nerves" 

 also. 



3d. The same difficulty exists in the location of cortical cen- 

 tres ; and supposed " pain centres " are probably sensation centres 

 of cutting and pricking. 



4th. The fact that intellectual states are pleasurable and 

 painful the author thinks differentiates pleasure and pain from 

 sensations. [ This, however, rests on a fallacy. Intellectual 

 states give rise to pleasure or pain which is just as real as a sensation- 

 ally produced pleasure or pain and has its physiological basis also.] 



5th. Pleasure and pain differ from sensation in the ease with 

 which one passes into the other. 



6th. In the case of pleasure-pain the states do not vary con- 

 comitantly with the intensity of the stimulus. 



7th. The relation between stimulus and result is inconstant. 



The objection at once suggested that mechanical and other stim- 

 ulation of nerves produces pain but not pleasure is met by the sug- 

 gestion that these methods are too crude to awaken pleasure and 

 especially by the fact that pleasure is largely due to summation of 

 stimuli. The question of sequence of temperature and tactile sensa- 

 tions on one hand and pain on the other may be dismissed. The 

 facts of analgesia which have been held to tell in favor of the existence 

 of special pain nerves may be interpreted to mean that the capacity to 

 experience one form of sensation of a certain part of the body is cut 

 off and with it its painful elements. The observations of Schiff sup- 

 posed to require special paths in the cord are interpreted in the same 

 way. Goldschneider's observations are not sustained by those of 



'Marshall, H. R. Jonrn. New. and Mental Disease, XIX, 2. 



