94 FRAGMENTS OF SCIENCE 



which Newton compared to the circles on a peacock's 

 tail. Disease makes people see visions and dream 

 dreams; but, in all such cases, could we examine the 

 organs implicated, we should, on philosophical grounds, 

 expect to find them in that precise molecular condition 

 which the real objects, if present, would superinduce. 



The relation of physics to consciousness being thus 

 invariable, it follows that, given the state of the brain, 

 the corresponding thought or feeling might be inferred; 

 or, given the thought or feeling, the corresponding state 

 of the brain might be inferred. But how inferred? It 

 would be at bottom not a case of logical inference at all, 

 but of empirical association. You may reply that many 

 of the inferences of science are of this character the in- 

 ference, for example, that an electric current, of a given 

 direction, will deflect a magnetic needle in a definite way. 

 But the cases differ in this, that the passage from the 

 current to the needle, if not demonstrable, is conceiv- 

 able, and that we entertain no doubt as to the final me- 

 chanical solution of the problem. But the passage from 

 the physics of the brain to the corresponding facts of 

 consciousness is inconceivable as a result of mechanics. 

 Granted that a definite thought, and a definite molecular 

 action in the brain, occur simultaneously; we do not pos- 

 sess the intellectual organ, nor apparently any rudiment 

 of the organ, which would enable us to pass, by a 

 process of reasoning, from the one to the other. They 

 appear together, but we do not know why. Were our 

 minds and senses so expanded, strengthened, and illumi- 

 nated, as to enable us to see and feel the very molecules 

 of the brain; were we capable of following all their mo- 

 tions, all their groupings, all their electric discharges, if 



