198 THE EEGULATION OF NUMBEKS 



by Malthas. The whole theory is one of the comparative rapidity 

 of the increase of population and of the increase of food. Popula- 

 tion, he said, when unchecked, increases in a geometrical ratio, 

 food only in an arithmetical ratio. Therefore there must always 

 be checks at work limiting population. He made a survey of the 

 social conditions in different countries, and pointed to the evidence 

 of the existence of various forms of vice and misery ; where moral 

 restraint was practised, there was less vice and misery ; where 

 no moral restraint was practised, vice and misery reached their 

 greatest prevalence. Furthermore the checks taken together 

 must always be effective ; it was, according to Malthus, merely 

 a question of what kind of checks should be in operation. It 

 was desirable in his view to increase ' moral restraint ' in order 

 to decrease ' vice ' and * misery '. It also follows that, if the 

 checks were always effective, there could be no such thing as 

 over-population. The conception of over-population, properly 

 speaking, did not enter into the theory at all. It belongs to the 

 later theory, which is based upon the productiveness of industry 

 an idea which finds no place in his book. 



In the later editions Malthus made certain reservations about 

 the impossibility of subsistence increasing faster than in an 

 arithmetical ratio. Facts incompatible with the theory regarding 

 the increase of population in America had come to light, and he 

 admitted the possibility of the increase of subsistence in a geo- 

 metrical ratio in new countries under certain conditions. He 

 maintained, however, that in general subsistence could not increase 

 faster than in an arithmetical ratio, and that his theory was 

 therefore in essential features still correct. The ratios were at 

 the basis of his theory, and sum up the whole essence of the 

 argument. It has frequently been said, however, that Malthus 

 did not attach much importance to the ratios. Professor Nichol- 

 son, for example, says that he used them ' not strictly but as 

 the basis for a simile '- 1 But Professor Cannan has shown that 

 there is no foundation whatever for this view, and quotes a passage 

 from Malthus exhibiting the importance which the latter attributed 

 to this part of his theory. 2 



That subsistence can only increase in an arithmetical ratio, or 

 in other words that the periodical additions to the average annual 



1 Nicholson, Political Economy, vol. i, p. 182, note. * Cannan, loc. cit., 



p 143. 



