THE EEGULATION OF NUMBEES 295 



those economically desirable. We shall, indeed, find later, when 

 deahng with war and when referring again to this subject in the 

 next chapter, that minor differences in the nearness of approach 

 as between countries in close proximity may be of considerable 

 importance. 



Within the mediaeval period, in spite of the very high death- 

 rate from disease, over-population occurred in England from time 

 to time. The fact that wages rose after the Black Death, and 

 that, after the decline in the population which took place in the 

 last years of the seventeenth century and in the opening years of 

 the eighteenth century, the average man was more prosperous, 

 points to this conclusion, as does the fact that frequent attempts 

 were made to render the restrictions upon marriage more severe. 

 •It seems probable that there was a similar tendency towards 

 over-population in most European countries, and the reason would 

 appear to be that postponement of marriage did not bring about 

 a sufficient restriction of increase ; postponement of marriage 

 was not in fact a sufficient substitute for abortion, infanticide, and 

 abstinence from intercourse, in spite of the prevalence of disease. 

 Under-population was less frequent ; when it occurred it was 

 sometimes due in part to a spirit of luxury and selfishness follow- 

 ing upon a period of expansion and prosperity, as in the later 

 history of Spain. There may for similar reasons be under- 

 population among the richer classes in Europe and America 

 to-day. 



With regard to the preceding period we have considerable 

 knowledge of the conditions in Greece and Eome. The history of 

 both countries presents very similar features. In the earlier 

 times practices restrictive of increase comparable with those 

 found among primitive races were operative. There followed a 

 vigorous epoch of colonization and then a period of decadence. 

 These periods of decadence have been much discussed. In these 

 discussions it is sometimes forgotten that the destruction of 

 capital in civil war on a large scale, especially in the last century 

 B. c. in Eome, must have diminished the numbers desirable. 

 But in spite of this it is clear that we are here again in the 

 presence of examples of decline, at least among the richer classes, 

 owing to the presence of selfishness and luxury ; this is certainly 

 the conclusion to which a study of Polybius leads as regards 

 Greece, while the admirable works of Sir Samuel Dill render the 



