298 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



their efforts toward uplifting humanity by enlight- 

 ened training. But these processes are complex in a 

 degree commensurate with the unparalleled com- 

 plexity of nervous functions, and hence both theory 

 and practice have been laggards, and the wisest of 

 men have studied the educational task one-sidedly 

 and without agreement among themselves. And so 

 long as men differ in temperament as well as in 

 powers of apprehension, they will differ in their 

 recommendations as to what we should strive to 

 attain in education and as to the means of attain- 

 ing every worthy end. 



In thinking of tendencies it has seemed to me that 

 we have too much neglected some obvious suggestions 

 given us by Nature herself. The educational sug- 

 gestions to which I would draw attention have their 

 basis in the biological substrata of our nature in 

 the differences between the self-preservative and the 

 sexual instincts. The recognition of the needs of 

 developing human nature involves an insight into 

 these different biological springs of activity and func- 

 tion. Has not this insight and understanding been 

 too often lacking in the minds of educators, and has 

 not this led to confusion and obscurity in consider- 

 ing the aims and methods of education ? We must 

 not try to make an absolute separation, since Nature 

 herself fuses these instincts, but shall we not learn 

 to trace and understand and nurture them separately ? 



The line of development of intellect is suggested 

 by the line of progress in a savage, i.e. qualities are 



