462 POPULAR SCIENCE MONTHLY. 



for definite functions. I think that anatomy and physiology bear me 

 out. And as for consciousness being intense only when 'nerve processes 

 are hesitant': what of the plunge into cool water on a hot day? what 

 of the enjoyment of music after a long aesthetic starvation? what of 

 our grief at the loss of a dear friend ? 



The second argument I take to be misleading. Vicarious function 

 has its limits. We can never see by aid of the auditory center, or hear 

 by aid of the visual. But the brain is bilaterally symmetrical; its 

 centers are arranged in a hierarchy, one above another; the connections 

 of center with center, direct and indirect, are multitudinous. Vicarious 

 function is thus, within wide limits, possible and natural; the excita- 

 tion whose 'principal path' is blocked finds several 'secondary paths' 

 still open. Let all the paths for a given form of excitation be blocked, 

 however, and what happens? Here is the supreme occasion when con- 

 sciousness might be useful; and consciousness does nothing. 



The third argument requires a somewhat more detailed exami- 

 nation. It is an empirical law, a rule of average, that pleasant things 

 are good for the organism, and unpleasant things bad. Pleasant 

 things, things that we like, are things which, presented as stimuli, 

 evoke movements of extension or approach; unpleasant things, things 

 which we do not like, repel us, — we shrink from them. The usual ex- 

 planation of the law is that organisms wliich (as psychical) liked 

 and (as physical) reached out after things that were bad for them 

 would, in the long run, be killed off. It is a condition of living that 

 the things sought after shall, on the whole, be good for the seeker. The 

 argument alleges that this explanation is insufficient. 'If pleasures 

 and pains' as such 'have no efficacy,' there is no reason why their rela- 

 tion should not be reversed; why the things that are bad for us should 

 not be pleasant, and the good things unpleasant. 



I think that the argument, by its very formulation, assumes the 

 causal efficacy which it is meant to prove. It assumes that a change 

 of mental process must necessarily condition a corresponding change 

 of motor reaction. Now there is good biological reason — psychology 

 apart — why the things that are bad for us should not be sought after, 

 and the things that are good for us neglected or repelled. But what 

 mental process colors the 'sought after' and the 'repelled' is simply a 

 question of fact. If it is the peculiar quality of pleasure and pain that 

 we are asked to account for, I reply that we can no more explain this 

 than we can explain why ether waves of a certain frequency correspond 

 to the sensation quality 'red' and not to that of 'blue.' If it is the con- 

 stancy of the mental accompaniment that is at issue — and this is sug- 

 gestM by the reference to an 'a priori rational harmony' — I reply that 

 the constancy is a given fact, accepted by parallelist and interactionist 

 alike, just as it is in the case of the colors. The argument, so far as I 



