ANIMAL AUTOMATISM. 2*25 



from consciousness. It must indeed be admitted, that, 

 if any one think fit to maintain that the spinal cord 

 below the injury is conscious, but that it is cut off from 

 any means of making its consciousness known to the 

 other consciousness in the brain, there is no means of 

 driving him from his position by logic. But assuredly 

 there is no way of proving it, and in the matter of con- 

 sciousness, if in anything, we may hold by the rule, "De 

 non apparentibus et de non existentibus eadem est ra- 

 tio." However near the brain the spinal cord is in- 

 jured, consciousness remains intact, except that the irri- 

 tation of parts below the injury is no longer represented 

 by sensation. On the other hand, pressure upon the 

 anterior division of the brain, or extensive injuries to 

 it, abolish consciousness. Hence, it is a highly probable 

 conclusion, that consciousness in man depends upon the 

 integrity of the anterior division of the brain, while the 

 middle and hinder divisions of the brain, and the rest 

 of the nervous centres, have nothing to do with it. And 

 it is further highly probable, that what is true for man 

 is true for other vertebrated animals. 



We may assume, then, that in a living vertebrated 

 animal, any segment of the cerebro-spinal axis (or spinal 

 cord and brain) separated from that anterior division of ) 

 the brain which is the organ of consciousness, is as com- 

 pletely incapable of giving rise to consciousness, as we 

 know it to be incapable of carrying out volitions. Nev- 

 ertheless, this separated segment of the spinal cord is 

 not passive and inert. On the contrary, it is the seat 



