198 SCIENTIST 



both parents become severely ill with anemia and usually 

 die before becoming adults. In parts of the world which 

 are free of severe malaria infection, the sickle cell gene is 

 wholly "bad" so far as we can see. In malarious areas, 

 however, one gene is "good" but two together are bad. 



The same principle of judging the value of quahties or 

 functions in terms of the surrounding circumstances can 

 be carried to higher levels involving issues which are more 

 obviously in the moral sphere. Careful anthropological 

 study has shown, for example, that marriage patterns and 

 sexual customs vary widely from place to place and from 

 time to time. In many parts of Asia it is still true, as it 

 was in the Western world until recently, that marriages 

 are arranged by parents with relatively httle reference to 

 the wishes of the partners. We tend to regard this as an 

 unjustified interference with personal liberty, but there is 

 much evidence that under certain circumstances the method 

 works very well. Even more drastic difference in marriage 

 patterns are of course well known. In some societies one 

 man may have several wives and in others one wife may 

 have several husbands. In the Western world such depar- 

 tures are looked upon as crimes. Scientists are for the most 

 part prepared to agree that under our conditions monogamy 

 is the best pattern and that it is immoral to depart from 

 it. But most scientists who worry about the matter at all 

 would find difficulty in asserting that other patterns are 

 bad in an absolute or universal sense. 



A particularly interesting and currently very important 

 example of the bearing of science on moral values is found 

 in what is currently known as the population problem. 

 Virtually all societies have set a very high value on marry- 

 ing and having children. Sterihty has been regarded as at 

 best a great misfortune and often as a punishment for some 

 obscure fault or sin. In many societies the failure of a 



