SCIENTIFIC MATERIALISM 



59 



Let any nerve, for example, be thrown 

 by morbid action into the precise state 

 of motion which would be communicated 

 to it by the pulses of a heated body, 

 surely that nerve will declare itself hot 

 the mind will accept the subjective inti- 

 mation exactly as if it were objective. 

 The retina may be excited by purely 

 mechanical means. A blow on the eye 

 causes a luminous flash, and the mere 

 pressure of the finger on the external 

 ball produces a star of light, 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 philo- 

 sophical grounds, expect to find them in 

 that precise molecular condition which 

 the real objects, if present, would super- 

 induce. 



The relation of physics to conscious- 

 ness being thus invariable, it follows that, 

 given the state of the brain, the corres- 

 ponding thought or feeling might be 

 inferred : or, given the thought or feel- 

 ing, 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 empi- 

 rical association. You may reply that 

 many of the inferences of science are of 

 this character the inference, for ex- 

 ample, 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 

 conceivable, and that we entertain no 

 doubt as to the final mechanical solution 

 of the problem. But the passage from 

 the physics of the brain to the corre- 

 sponding facts of consciousness is in- 

 conceivable as a result of mechanics. 

 Granted that a definite thought and a 

 definite molecular action in the brain 

 occur simultaneously, we do not possess 

 the intellectual organ, nor apparently any 

 rudiment of the organ, which would 

 enable us to pass, by a process of reason- 

 ing, from the one to the other. They 

 appear together, but we do not know why. 



Were our minds and senses so expanded, 

 , strengthened, and illuminated, as to 

 enable us to see and feel the very mole- 

 cules of the brain ; were we capable of 

 following all their motions, all their 

 groupings, all their electric discharges, if 

 such there be ; and were we intimately 

 acquainted with the corresponding states 

 of thought and feeling ; we should be -as 

 far as ever from the solution of the prob- 

 lem, " How are these physical processes 

 connected with the facts of conscious- 

 ness?" The chasm between the two 

 classes of phenomena would still remain 

 intellectually impassable. Let the con- 

 sciousness of love, for example, be asso- 

 ciated with a right-handed spiral motion 

 of the molecules of the brain, and the 

 consciousness of hate with a left-handed 

 spiral motion. We should then know, 

 when we love, that the motion is in one 

 direction, and, when we hate, that the 

 motion is in the other ; but the " WHY ?" 

 would remain as unanswerable as before. 

 In affirming that the growth of the 

 body is mechanical, and that thought, as 

 exercised by us, has its correlative in the 

 physics of the brain, I think the position 

 of the " Materialist " is stated, as far as 

 that position is a tenable one. I think 

 the materialist will be able finally to 

 maintain this position against all attacks; 

 but I do not think, in the present condi- 

 tion of the human mind, that he can pass 

 beyond this position. I do not think he 

 is entitled to say that his molecular 

 groupings and motions explain every- 

 thing. In reality they explain nothing. 

 The utmost he can affirm is the associa- 

 tion of two classes of phenomena, of 

 whose real bond of union he is in abso- 

 lute ignorance. The problem of the con- 

 nection of body and soul is as insoluble 

 in its modern form as it was in the pre- 

 scientific ages. Phosphorus is known to 

 enter into the composition of the human 

 brain, and a trenchant German writer 

 has exclaimed, " Ohne Phosphor, kein 

 Gedanke !" That may or may not be the 

 case ; but even if we knew it to be the 

 case, the knowledge would not lighten 

 our darkness. On both sides of the zone 



