+109. Greek degeneracy.+ The decline of the Greeks in the three centuries before our era is so great and sudden that it is very difficult to understand it. The best estimate of the population of the Peloponnesus in the second century B.C. puts it at one hundred and nine per square mile.[135] Yet the population was emigrating, and population was restricted. A pair would have but one or two children. The cities were empty and the land was uncultivated.[136] There was neither war nor pestilence to account for this. It may be that the land was exhausted. There must have been a loss of economic power so that labor was unrewarded. The mores all sank together. There can be no achievement in the struggle for existence without an adequate force. Our civilization is built on steam. The Greek and Roman civilization was built on slavery, that is, on an aggregation of human power. The result produced was, at first, very great, but the exploitation of men entailed other consequences besides quantities of useful products. It was these consequences which issued in the mores, for, in a society built on slavery as the form of productive industry, all the mores, obeying the strain of consistency, must conform to that as the chief of the folkways. It was at the beginning of the empire that the Romans began to breed slaves because wars no longer brought in new supplies.[137] Sex, vice, laziness, decline of energy and enterprise, cowardice, and contempt for labor were consequences of slavery, for the free.[138] The system operated, in both the classical states, as a selection against the superior elements in the population. This effect was intensified by the political system. The city became an arena of political struggle for the goods of life which it was a shame to work for. Tyrannies and democracies alternated with each other, but both alike used massacre and proscription, and both thought it policy to get rid of troublesome persons, that is, of those who had convictions and had courage to avow them. Every able man became a victim of terrorism, exerted by idle market-place loafers. The abuse of democratic methods by those-who-had-not to plunder those-who-had must also have had much to do with the decline of economic power, and with the general decline of joy in life and creative energy. It would also make marriage and children a great and hopeless burden. Abortion and sex vice both directly and indirectly lessened population, by undermining the power of reproduction, while their effect to destroy all virile virtues could not fail to be exerted.[139] It was another symptom of disease in the mores that the number of males in the Roman empire greatly exceeded the number of females.[140] The Roman system used up women.