74 Malthusianism and the 



diseases which seem to be generated by a scarcity of 

 the means of subsistence, and all those causes inde- 

 pendent of this scarcity, whether of a moral or physical 

 nature, which tend prematurely to weaken or destroy 

 the human frame." . . . " The positive checks to popu- 

 lation are extremely various, and include every cause, 

 whether arising from vice or misery, which in any degree 

 contribute to shorten the natural duration of human 

 life. Under this head, therefore, may be enumerated 

 all the unwholesome occupations, severe labour, and 

 exposure to the seasons, extreme poverty, bad nursing 

 of children, great towns, excess of all kinds, the whole 

 train of diseases and epidemics, war, plague, and 

 famine. . . . On examining these obstacles to the 

 increase of population, which I have classed under the 

 heads of preventive and positive checks, it will appear 

 that they are all resolvable into moral restraint, vice, 

 and misery." 



In his reply to Mr. Godwin, who differed from his 

 view, Malthus writes : "I believe that Mr. Godwin 

 would find it difficult to name any check which in past 

 ages has contributed to keep down the population to 

 the level of the means of subsistence that does not 

 fairly come under some form of vice or misery " ; and, 

 thereafter, he eliminates, as I have already shown, the 

 theory of moral restraint as an operative check. 



Here we must remember that Darwin incorporated 

 this part of the Malthusian theory and extended its 

 operation over the whole field of animated nature. 

 As he said, and as has been already quoted : " It is the 

 doctrine of Malthus applied with manifold force to the 

 whole animal and vegetable kingdom " ; and this he 

 called the " struggle for existence," resulting in the 

 " survival of the fittest," or " natural selection." 



Unfortunately Malthus did not possess the means of 

 ascertaining the movements of population and their 



