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SCIENCE 



[N. S. Vol. XL. No. 1027 



ceptions of life and death, the coming 

 generations are determined to get more out 

 of this world than their forefathers did. 

 Is it then to be supposed that when science 

 puts into their hand means for the allevia- 

 tion of suffering immeasurable, and for 

 making this world a happier place, that 

 they will demur to using those powers? 

 The intenser struggle between communities 

 is only now beginning, and with the ap- 

 proaching exhaustion of that capital of 

 energy stored in the earth before man 

 began it must soon become still more fierce. 

 In England some of our great-grandchil- 

 dren will see the end of the easily acces- 

 sible coal, and, failing some miraculous dis- 

 -aoveiiy of available energy, a wholesale 

 ^reduction in population. There are races 

 -■who have shown themselves able at a word 

 1i)0 throw off all tradition and take into their 

 service every power that science has yet 

 offered them. Can we expect that they, 

 when they see how to rid themselves of the 

 ever-increasing weight of a defective popu- 

 lation, will hesitate? The time can not be 

 far distant when both individuals and com- 

 munities will begin to think in terms of 

 biological fact, and it behooves those who 

 lead scientific thought carefully to con- 

 sider whither action should lead. At pres- 

 ent I ask you merely to observe the facts. 

 The powers of science to preserve the de- 

 fective are now enormous. Every year 

 these powers increase. This course of ac- 

 tion must reach a limit. To the deliberate 

 intervention of civilization for the preser- 

 vation of inferior strains there must sooner 

 or later come an end, and before long na- 

 tions will realize the responsibility they 

 have assumed in multiplying these " cankers 

 of a calm world and a long peace." 



The definitely feeble-minded we may 

 with propriety restrain, as we are begin- 

 ning to do even in England, and we may 

 safely prevent unions in which both parties 



are defective, for the evidence shows that 

 as a rule such marriages, though often 

 prolific, commonly produce no normal 

 children at all. The union of such social 

 vermin we should no more permit than we 

 would allow parasites to breed on our own 

 bodies. Further than that in restraint of 

 marriage we ought not to go, at least not 

 yet. Something too may be done by a re- 

 form of medical ethics. Medical students 

 are taught that it is their duty to prolong 

 life at whatever cost in suffering. This 

 may have been right when diagnosis was 

 uncertain and interference 'usually of 

 small effect; but deliberately to interfere 

 now for the preservation of an infant so 

 gravely diseased that it can never be happy 

 or come to any good is very like wanton 

 cruelty. In private few men defend such 

 interference. Most who have seen these 

 eases lingering on agree that the system is 

 deplorable, but ask where can any line be 

 drawn. The biologist would reply that in 

 all ages such decisions have been made by 

 civilized communities with fair success 

 both in regard to crime and in the closely 

 analogous case of lunacy. The real reason 

 why these things are done is because the 

 world collectively cherishes occult views of 

 the nature of life, because the facts are 

 realized by few, and because between the 

 legal mind — to which society has become 

 accustomed to defer — and the seeing eye, 

 there is such physiological antithesis that 

 hardly can they be combined in the same 

 body. So soon as scientific knowledge be- 

 comes common property, views more rea- 

 sonable and, I may add, more humane, are 

 likely to prevail. 



To all these great biological problems 

 that modem society must sooner or later 

 face there are many aspects besides the 

 obvious ones. Infant mortality we are 

 asked to lament without the slightest 

 thought of what the world would be like if 



