io DEVELOPMENT AND PURPOSE CHAP. 



the teaching of biology and that of civilisation has at length 

 had its effect and the trend of biological opinion now is to 

 interest itself in the artificial selection of types for repro- 

 duction as a civilised substitute for the elimination by 

 natural forces of those who cannot stand on their own feet. 

 With the value of this view, which represents the effects 

 of sociological criticism impinging on a more ruthless 

 doctrine, we are not for the moment concerned. What 

 is of interest is the entire subjugation of the life of mind 

 to biological conditions. It is the survival value of certain 

 types of nerve structures which has given birth to the world 

 of mind, and which remains the condition of further 

 development within that world. Mental vigour, moral 

 worth, as properly estimated, are means by which a type 

 can maintain and improve itself. Whatsoever soul is hard, 

 whatsoever is unlovely, what there is of self-assertion, if 

 there is any ruthlessness, if there is any unimaginative self- 

 centred push, this type shall prevail, for of such is the 

 process of evolution. 



4. If this were indeed so, some might think it better that 

 the process of evolution should cease. But it is worth 

 enquiring afresh whether the account given by biology of 

 the part played by mind in organic evolution is an adequate 

 account. For this purpose it will be necessary to take a 

 summary view of the actual phenomena of mental develop- 

 ment so far as they can be ascertained both in animals and 

 in man. This is attempted in the first part of this volume, 

 and it will conduce to clearness if the broad results are 

 briefly stated by way of anticipation. 



Our review then will go to show that, without involving 

 any discontinuity either as between the lowest living 

 organism and the intelligent animal, or as between the 

 intelligent animal and man, without, that is to say, involving 

 any change so sudden and great that we cannot conceive 

 it as bridged over by the cumulative effort of small varia- 

 tions, the facts of growth when disinterestedly studied do 

 reveal changes which we ought to regard as changes of 

 kind, and indeed of a kind very material to the interpreta- 

 tion of evolution, of the position of mind in reality, and 

 of the future possibilities of man. That cumulative 



