KOn VIUCIIOW AND EVOLUTION. 651 



are content to make your soul a poetic rendering of a 

 phenomenon which refuses the yoke of ordinary physical 

 laws, I, for one, would not object to this exercise of 

 ideality/"* Professor Virchow's meaning, I admit, re- 

 quired illustration; but I do not clearly see how the 

 quotation from me subserves this purpose. I 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: 

 pofoundly 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 feeling 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 un- 

 locked the muscle? The sense of pain, it may be replied... 

 But how can a sense of pain, or any other state of conscious- 

 ness, 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 molecule? Try to express the 1 

 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 inj 

 themselves, and would go on just as they do if conscious-- 

 ness were not at all implicated. 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. 



Four years ago, I wrote thus: " Do states of conscious- 

 ness enter as links into the chain of antecedence and 



* Presidential address delivered before the Birmingham and Mid- 

 land Institute, October 1, 1877. l<ori>iiqhtiu Review, Nov. 1, 

 1877, p. C07. 



