258 HEREDITY. 



traits of the race, it also touches their mental traits. 

 Scientific observers are agreed in assuming that there 

 is a law of averages applying to mental and moral as 

 well as to the physical capacities in the individuals 

 of the race. At the top of the mental scale we have 

 genius ; at the bottom stupidity. Determine the 

 position of the average line between these two ex- 

 tremes, divide the space between top and bottom 

 equally, and then ascertain the number of cases rep- 

 resented by any one space, high or low, and you may 

 determine by the law of averages the number in 

 every other space. (See Galton's use of Quete- 

 let's law, Hereditary Genius, American edition, pp. 

 26-32.) 



How can the average ability of the race be raised 

 by the application of the laws of hereditary descent ? 



In putting this question before you, I am perfectly 

 aware that I am venturing into chaos, or, at least, 

 into regions where it is difficult to find firm ground 

 on which to put down the foot. I am not speaking 

 here at random, but cautiously selecting the few 

 sound conclusions which science has reached, and 

 combining them in such a manner that we may see, 

 if our eyes are open, the trend of investigation on 

 this most blazing of all social themes. It is the duty 

 of this lectureship not to skip difficulties. [Ap- 

 plause.] Milton, you know, sends out Satan across 

 chaos, and he is to build a road under himself as 

 he proceeds to the Garden of Eden. I am on an 

 expedition of similar difficulty, but of diametrically 

 opposite purpose and direction. [Applause.] In the 



