444 Living in a World of Change 



him genetically. And the outstanding difference has to do 

 with what we call mental qualities. 



What follows from the doctrine so far as concerns the 

 origin of mind? Many people brought up on the biblical 

 account of creation were ready at once to reinterpret that 

 as a poetical generalization. Of these, however, large num- 

 bers balked when it came to include mentality in the evolu- 

 tionary scheme. One reason for this was of course the 

 emphasis which Darwin and his disciples placed upon con- 

 tinuity. It would be necessary to find an unbroken chain 

 of mentalities linking man with the simplest forms. Not 

 only was the knowledge at the time inadequate, but the very 

 thought strained the imagination. The human mind is 

 qualitatively different from the mind of the ameba or the 

 turnip. It was inconceivable that it should have arisen by 

 a process of slow increments. On the other hand, many 

 enthusiastic evolutionists accepted the implications in prin- 

 ciple and were content to leave to later investigations the 

 establishment of the principle as a fact. 



At the present time we need not be troubled by these 

 considerations. Evolution need not mean the gradual transi- 

 tion through imperceptible increments. Variations need no 

 longer be considered merely plus and minus fluctuations. 

 It is still inconceivable that man differs from ameba " only 

 in degree." But today we know there are mutations, and 

 these include qualitatively new characters. From a philo- 

 sophical point of view, we are able to retain our reliance 

 upon causal continuity and still make allowance for the ap- 

 pearance of novelties, even if we do not understand the 

 '* mechanism " of transition. If we think of the mental 

 category as an emergent from specialized living matter under 

 specialized circumstances, we do not of course " explain " 

 the origin of mind. We accept it, for purposes of further 

 study, just as we accept the emergence of alcohol and carbon 

 dioxid from the fermentation of sugar, or the emergence of 

 an electric current from a dry cell — processes that we can 

 control in practice, but not yet ** explain." 



