86 SCIENCE AND PHILOSOPHY OF THE ORGANISM 



logical part of the question concerned here, which is by no 

 means an easy problem, and has been treated rather im- 

 properly in almost all essays on it. Even Johannes 

 Mueller was wrong when he paralleled his principle with the 

 Kantian doctrine of apriorism, with which it has nothing 

 at all to do. Intentionally we shall take up the position 

 of naive realism in the short discussion that is to follow, 

 and shall not hesitate to enter for a moment into the field 

 of pseudo-psychology. 



We simply ask, is it true that the process of nervous 

 conduction is always the same, and that specific qualities 

 reach the brain only because specific parts of it have been 

 stimulated without any relation to the nature of the 

 stimulus ? It seems to me, I confess, that we are quite 

 unable to say at present whether it is true or not. 

 Certainly there is not a single instance brought forward 

 in favour of Mueller's principle that can be said to be above 

 all doubt. The often discussed fact, for instance, that 

 cutting the optic nerve gives the sensation of light proves 

 nothing, since, as all modern authors agree, this operation 

 is not possible without stimulating the retina to a certain 

 extent before the nerve has been cut quite through. The 

 electrical phenomena, on the other hand, that are exhibited 

 equally well in any stimulation of nerves whatever, are 

 only secondary phenomena, and prove nothing either for 

 or against the problem of qualitative differences in nervous 

 conduction. There remain only the facts strange as they 

 are of a localised feeling of say the hand or the fingers 

 after the amputation of the whole arm, but not a single 

 one of these amputations has been performed on an 

 individual who had not already received the specific sensa- 



