But moral motives are stronger even than physical forces in checking the numerical progress of a race. Amongst backward peoples unusual indulgence and consequent disease may lead to the diminution or even extinction of the stock; amongst civilised peoples the motives which attain this result are rather prudential, and are concerned with an ideal of life which perhaps increases the efficiency of the individual, but builds up his healthy and pleasurable environment at the expense of the perpetuity of the race. The fact that the Roman and Italian physique was not degenerating is abundantly proved by the military history of the last hundred years of the Republic. This is one of the greatest periods of conquest in the history of the world. The Italy, whom we are often inclined to think of as exhausted, could still pour forth her myriads of valiant sons to the confines marked by the Rhine, the Euphrates and the Sahara; and the struggle of the civil wars, which followed this expansion, was the clash of giants. But this vigour was accompanied by an ideal, whether of irresponsibility or of comfort, which gave rise to the growing habit of celibacy--a habit which was to stir the eloquence of many a patriotic statesman and finally lead to the intervention of the law. When the censor of 131 uttered the memorable exhortation "Since nature has so ordained that we cannot live comfortably with a wife nor live at all without one, you should hold the eternal safety of the State more dear than your own brief pleasure," [181] it is improbable that he was indulging in conscious cynicism, although there may have been a trace of conscious humour in his words. He was simply bending to the ideal of the people whom he saw, or imagined to be, before him. The ideal was not necessarily bad, as one that was concerned with individual life. It implied thrift, forethought, comfort--even efficiency of a kind, for the unmarried man was a more likely recruit than the father of a family. But it sacrificed too much--the future to the present; it ignored the undemonstrable duty which a man owes to the permanent idea of the State through working for a future which he shall never see. It rested partly on a conviction of security; but that feeling of security was the most perilous sign of all.