194 SCIENTIST 



against the disadvantages — the cost in money, in doctors' 

 and nurses' time, and above all in the emotional strain of 

 fighting a long-drawn-out battle with death. In a few years 

 it will be literally true that at least the time at which most 

 people die will be determined by a doctor or by a group 

 of people including doctors, who will decide not to do 

 something they know how to do. 



At the other end of the life span, science is slowly but 

 steadily providing the background for decisions in regard 

 to how many and what kind of children will be born. In 

 all civilized countries parents use scientific knowledge to 

 determine the size of their families, and increasingly the 

 question of the overall size of national populations is be- 

 coming a matter of public discussion. Clearly many "value 

 problems," both esthetic and moral, are involved in such 

 discussions, but science is intimately involved in them also. 



Although knowledge of human genetics is still in its 

 infancy, there is already enough to be taken into serious 

 account in decisions about family planning. Some nations 

 have already employed genetic ideas very crudely in laws 

 aimed at preventing criminals and other defectives from 

 having children. On an individual basis, parents increas- 

 ingly consult physicians and geneticists about the chance of 

 having defective children when the parents are known to 

 carry defects of one sort or another. In certain very clear 

 cases, the defects are so serious and the genetic evidence 

 so compeUing that the decision is relatively simple. In 

 other cases, the genetic evidence can only be expressed 

 as a not very large probability and the danger of having a 

 child with a relatively mild defect must be weighed against 

 many other factors which constitute important values to 

 the prospective parents and to society. In practice, it is 

 very difficult for the doctor or the geneticist not to get 

 involved with these value problems, however much he 



