Genetics and Ethics 3°3 



natural processes. Natural phenomena are not the results of voli- 

 tions big or little, good or bad, but of all the events which have 

 gone before. To the man of science nature is not the mere caprice 

 of god or devil, to be lightly altered for a child's whim ; nature is, 

 as Bishop Butler said, that which is "stated, fixed, settled," eter- 

 nal process moving on, the same yesterday, to-day and forever. 



From sands to stars, from the immensity of the universe to 

 the minuteness of the electron, in living things no less than in life- 

 less ones, science recognizes everywhere the inevitable sequence 

 of cause and effect, the universality of natural law. Man also is a 

 part of nature, a part of the great mechanism of the universe, and 

 all that he is and does is limited and prescribed by laws of na- 

 ture. Every human being comes into existence by a process of 

 development, every step of which is determined by antecedent 

 causes. 



i. The Determinism of Heredity. — There can be no doubt that 

 the main characteristics of every living thing are unalterably fixed 

 by heredity. Men differ from horses or turnips because of their 

 inheritance. Our family traits were determined by the heredi- 

 tary constitutions of our ancestors, our inherited personal traits 

 by the hereditary constitutions of our fathers and mothers. By 

 the shuffle and deal of the hereditary factors in the formation of 

 the germ cells and by the chance union of two of these cells in 

 fertilization our hereditary natures were forever sealed. Our 

 anatomical, physiological, psychological possibilities were prede- 

 termined in the germ cells from which we came. All the main 

 characteristics of our personalities were born with us and cannot 

 be changed except within relatively narrow limits. "The leopard 

 cannot change his spots nor the Ethiopian his skin," and "though 

 thou shouldst bray a fool in a mortar with a pestle yet will not his 

 foolishness depart from him." Race, sex, mental capacity are de- 

 termined in the germ cells, perhaps in the chromosomes, and all 

 the possibilities of our lives were there fixed, for who by taking 

 thought can add one chromosome, or even one determiner to his 

 organization ? 



