456 The Doctrine of Evolution. 



are involved when we try to conceive the Infinite and Eter- 

 nal Power as psychical in His nature, I have, in the chapter 

 on Matter and Spirit, in that same book, taken equal pains 

 to show that we are logically compelled thus to'conceive 

 Him. 



One's attitude toward such problems is likely to be de- 

 termined by one's fundamental conception of psychical life. 

 To a materialist the ultimate power is mechanical force, and 

 psychical life is nothing but the temporary and local result 

 of "fleeting collocations of material elements in the shape 

 of nervous systems. Into the endless circuit of transforma- 

 tions of molecular motion, says the materialist, there enter 

 certain phases which we call feelings and thoughts ; they 

 are part of the circuit, they arise out of motions of material 

 molecules, and disappear by being retransformed into such 

 motions ; hence, with the death of the organism in. which 

 such motions have been temporarily gathered into a kind 

 of unity, all psychical activity and all personality are ipso 

 facto abolished. Such is the materialistic doctrine, and 

 such, I presume, is what Prof. Haeckel has in mind when 

 he asserts that the belief in an immortal soul is incompati- 

 ble with the doctrine of evolution. The theory commonly 

 called that of the correlation of forces, and which might 

 equally well or better be called the theory of the meta- 

 morphosis of motions, is indispensable to the doctrine of 

 evolution. But for the theory that light, heat, electricity, 

 and nerve-action are different modes of undulatory motion 

 transformable one into another, and that similar modes of 

 motion are liberated by the chemical processes going on 

 within the animal or vegetal organism, Mr. Spencer's work 

 could never have been done. That theory of correlation 

 and transformation is now generally accepted, and is often 

 appealed to by materialists. A century ago Cabanis said 

 that the brain secretes thought as the liver secretes bile. 

 If he were alive to-day, he would doubtless smile at this old 

 form of expression as crude, and would adopt a more sub- 

 tle phrase ; he would say that " thought is transformed mo- 

 tion." 



Against this interpretation I have maintained that the 

 theory of correlation not only fails to support it, but actu- 

 ally overthrows it. The arguments may be found in the 

 chapter on Matter and Spirit in my Cosmic Philosophy, 

 published in 1874, and in the essay entitled A Crumb for 

 the Modern Symposium, written in 1877 and reprinted in 



