THE NERVOUS SYSTEM AND CONSCIOUSNESS. 155 



less the characteristics of consciousness, as we know them and are 

 obliged to know them, resemble the characteristics of brain-activity as 

 we know them and are obliged to know them. It will not avail to say 

 there are striking differences between heat, electricity, and light ; 

 there are striking resemblances one positive, constant resemblance 

 they are all modes of motion. Between the characteristics of con- 

 sciousness and the characteristics of nerve-matter, as we know them, 

 there are no resemblances whatsoever. If the smaller physiological 

 materialists (for the larger do it fully) would but think it worth their 

 while, and a truly scientific procedure, to fasten their attention upon 

 consciousness, they might be struck by its peculiarities. The distinct- 

 ive features of consciousness in general have often been indicated. I 

 shall restate them here as they have been compared with nerve-activi- 

 ties, arranging them in pairs for the sake of clearness : 



1. Nerve-activities : 



All are modes of extension and motion. 

 Consciousness-activities : 



None can be conceived as extended or moving. 



2. Nerve-activities : 



They may be observed through the senses. 

 Consciousness-activities : 



They are never known through the senses. 

 8. Nerve-activities : 



They are external to the observer. 

 Consciousness-activ ities : 



They are internal to the observer. 



4. Nerve-activ ities : 



Each may be directly seen at the same time by many observers. 

 Conscio usness-activ ities : 



They can be directly known by one person only, viz., he who 

 experiences them. 



5. Nerve-activities : 



They consist of parts external to each other and are divisible. 

 Consciousness-activities : 



They have no distinction of parts and are indivisible. 

 It may surprise some readers to be told that this contrast is fully 

 recognized by many leading upholders of evolution. Mr. Spencer 

 says, " There lies before us, in the study of consciousness, a class of 

 facts absolutely without any perceptible or conceivable community of 

 nature with the facts that have occupied us in the study of the nerv- 

 ous system." 



Dr. Tyndall (" Address on Scientific Materialism," Norwich) says : 

 " The passage from the physics of the brain to the corresponding facts 

 of consciousness is unthinkable. The chasm between the two classes 

 of phenomena is intellectually impassable." Professor Huxley says : 

 "I know nothing whatever, and never expect to know anything, of the 



