178 . POPULAR SCIENCE MONTHLY. 



cording to the definitions with which our psychologies start, it is in- 

 deed true that mind and matter must either interact or in some way 

 correspond without interaction. If the psychologist asserts that each 

 brain is a center for the creation of new energy or for interference 

 with the configuration of a material system, he obviously subverts the 

 principal generalizations of physical science. He doubtless has a right 

 to do so, but in the same sense as the cow has a right to stop the loco- 

 motive engine. If, on the other hand, the psychologist modestly ad- 

 mits that mind does not affect the physical order, he runs counter to 

 the principal generalization of biological science. If pleasure and 

 pain, memory and forethought, are of no use in the struggle for or- 

 ganic survival, why should they ever have evolved? 



It requires less temerity to question the theories of biology than 

 to deny the laws of physics. The survival of the fit may be regarded 

 as a truism rather than as a discovery, if we call that fit which does 

 survive. But fitness of this kind is so protean in its manifestations 

 in organic nature that the formula becomes somewhat vague. If an 

 animal is inconspicuously colored, it is protective coloration and so 

 useful; if conspicuously colored, it is directive coloration and so use- 

 ful. It is somewhat difficult to guess the utility of the fantastic shape 

 and color of each deep-sea fish that lives in perpetual darkness. Then 

 there are admittedly correlated variations, by-products of evolution, 

 diseases and the like ; it may be that consciousness is that sort of thing. 

 If some kinds of consciousness, as the sense of beauty, are of no use 

 in the struggle for existence, all the rest may be equally useless — an 

 efflorescence exhibited when there is friction due to lack of adjust- 

 ment between the organism and its environment. Finally, and most 

 plausibly, it may be argued that minds have evolved in answer to final 

 causes, and that organic evolution must adopt the principles of psy- 

 chology rather than prescribe to it. 



The interactionist seems to be in a worse plight than the parallelist 

 in the conflicts with our sister sciences, but the case is different before 

 the court of common sense. The present writer can not conceive how 

 the parallelist gets outside the limits of consciousness. Why does he 

 want any thing to run parallel with the only thing he knows? He 

 becomes at once a subjective idealist, and there may be no harm in 

 that. But when the subjective idealist wants to live in a world with 

 other men, he reinvents the distinctions that he had verbally obliter- 

 ated. What he knows about the physical world is what his senses and 

 the physicists tell him; if he likes to call it all consciousness or the 

 unconscious, mind-stuff, will or God's thought, this may be emotion- 

 ally stimulating, but no fact or law is thereby altered. The world 

 may be God's thought, without in the least preventing the parallelist 

 from thinking illogically. 



