BRITISH ASSOCIATION. 355 



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 cases 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 civilised 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 realised 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 becomes common property, views more 

 reasonable and, I may add, more humane, are likely to prevail. 



To all these great biological problems that modern 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 the majority of these infants were 

 to survive. The decline in the birth-rate in countries already over- 

 populated is often deplored, and we are told that a nation in which 

 population is not rapidly increasing must be in a decline. The 

 slightest acquaintance with biology, or even school-boy natural 

 history, shows that this inference may be entirely wrong, and that 

 before such a question can be decided in one way or the other, hosts 

 of considerations must be taken into account. In normal stable 

 conditions population is stationary. The laity never appreciates, 

 what is so clear to a biologist, that the last century and a quarter, 

 corresponding with the great rise in population, has been an 

 altogether exceptional period. To our species this period has been 

 what its early years in Australia were to the rabbit. The exploitation 

 of energy-capital of the earth in coal, development of the new 

 countries, and the consequent pouring of food into Europe, the 

 application of antiseptics, these are the things that have enabled the 

 human population to increase. I do not doubt that if population 

 were more evenly spread over the earth it might increase very much 

 more ; but the essential fact is that under any stable conditions a 

 limit must be reached. A pair of wrens will bring off a dozen young 

 every year, but each year you will find the same number of pairs in 

 your garden. In England the limit beyond which under present 

 conditions of distribution increase of population is a source of 

 suffering rather than of happiness has been reached already. 

 Younger communities living in territories largely vacant are very 

 probably right in desiring and encouraging more population. Increase 

 may, for some temporary reason, be essential to their prosperity. 

 But those who live, as I do, among thousands of creatures in a state 

 of semi-starvation will realise that too few is better than too many, 



