FRANCIS G ALTON 183 



existence of hereclit} r in man. It is still urged by some that in the 

 mental qualities nurture is of far greater importance than nature. So 

 at the time when he struck out in a new direction in biology it was by 

 no means obvious that heredity — to say nothing of the laws of inherit- 

 ance — was common to man and the lower organisms. Our present be- 

 lief that this is true is largely due to the labors of Galton and his 

 school. 



Again we must remember that even in " Hereditary Genius " he 

 had definitely in view the possibility of race improvement. However 

 unsuited human material may be for unravelling recondite laws of 

 inheritance, it must be admitted that from its high sociological im- 

 portance the problems of heredity and environmental influence must 

 be investigated in the human species. 



To discuss Galton's work on inheritance in greater detail at the 

 present time would be a thankless task, for his immense service to the 

 science of heredity and the great value of his methods for some prob- 

 lems of inheritance have been generally obscured by the enthusiasm 

 over other means of attack. With a little time and a bit of Galtonian 

 patience we shall perhaps arrive at a saner point of view than that now 

 prevailing. 



Galton's application of quantitative methods to the problems of 

 human faculty and heredity is one of the forces which has gone into 

 the formation of the biometric school of biologists. His influence in 

 connection with this school is his greatest service to biology. 



It may not be amiss to state here what the fundamental articles of 

 faith of the biometrician are. They seem both simple and highly 

 reasonable. 



First, the biometrician requires that all observations shall be re- 

 duced, in so far as the material permits, to a quantitative basis. Galli- 

 leo's injunction to measure what is measurable and to render measur- 

 able what is not, must become the ideal of biologists, as it has long 

 been of physicists, chemists and astronomers. "When a sufficient number 

 of biologists have made this the guiding principle of their work, the 

 hoary and decrepit distinction between precise and biological sciences 

 will pass away. 



Second, the biometrician insists that generalizations be drawn only 

 from adequately large series of observations. The living substance is 

 so subject to as yet unknowable, or at least immeasurable, influences 

 that we dare not trust the " individual instance " ; it is only upon a 

 large number — and sometimes a very large number — of individual in- 

 stances that conclusions of value may be drawn. 



Third, the biometrician demands that the actual data, quantitative 

 in quality and adequate in amount, shall be interpreted by sound logic. 

 The most suitable logic, he believes, is that of the mathematician. This 

 is agreed upon in theory by the most severely and variously disciplined 



