406 FKAGMENTS OF SCIENCE. 



do not even know whether I am cited as meriting praise 

 or deserving opprobrium. In a far coarser fashion this 

 utterance of mine has been dealt with in other places: it 

 may therefore be worth while to spend a few words 

 upon it. 



The sting of a wasp at the finger-end announces 

 itself to the brain as pain. The impression made by 

 the sting travels, in the first place, with comparative 

 slowness along the nerves affected; and only when it 

 reaches the brain have we the fact of consciousness. 

 Those who think most profoundly on this subject hold 

 that a chemical change, which, strictly interpreted, is 

 atomic motion, is, in such a case, propagated along the 

 nerve, and communicated to the brain. Again, on feel- 

 ing the sting I flap the insect violently away. What 

 has caused this motion of my hand? The command 

 from the brain to remove the insect travels along the 

 motor nerves to the proper muscles, and, their force 

 being unlocked, they perform the work demanded of 

 them. But what moved the nerve molecules which 

 unlocked the muscle? The sense of pain, it may be 

 replied. But how can a sense of pain, or any other 

 state of consciousness, make matter move? Not all 

 the sense of pain or pleasure in the world could lift a 

 stone or move a billiard-ball; why should it stir a mole- 

 cule? Try to express the motion numerically in terms 

 of the sensation, and the difficulty immediately appears. 

 Hence the idea long ago entertained by philosophers, 

 but lately brought into special prominence, that the 

 physical processes are complete in themselves, and would 

 go on just as they do if consciousness were not at all im- 

 plicated. Consciousness, on this view, is a kind of by- 

 product inexpressible in terms of force and motion, and 

 unessential to the molecular changes going on in the 

 brain. 



