But natural monogamy is as free from sex service as from domestic service. The pairing species adhere to their mating season as do the polygamous ones, or even the promiscuous. Man is the only animal using this function out of season and apart from its essential purpose. These natural monogamists are not “ascetics.” They are not dominated by religious doctrine or civil law. They fulfill their natural desires with the utmost freedom, but these desires do not move them out of season. The human species, with all its immense advantages, has made many conspicuous missteps. Its eating habits are such as to have induced a wide assortment of wholly unnecessary diseases; its drinking habits are glaringly injurious; and its excessive indulgence in sex-waste has imperiled the life of the race. Domestic morality vaguely recognized some duty to society and sought through religion to limit masculine desires or at least to restrict their indulgence to marriage. But the desires of a vigorous polygamist are not easily restricted to one wife; and our polygamous period was far longer than that of the recently established monogamy. It is a most reassuring fact in social evolution that monogamy, naturally belonging to our species, has persisted among the common people and in popular ideals: even in “The Arabian Nights” the love story is always about one man and one woman, never of the mad passion for a harem! So with the accelerated progress of recent centuries monogamous union becomes accepted, and is carefully buttressed by the law, while religion, with commandments and ceremonies, does its best to establish “the sanctity of marriage.” But as religion, law, and family authority were all in the hands of men, they naturally interpreted that sanctity to suit themselves, ignored the religious restrictions, and so handled the law as to apply its penalties to but one party in a dual offense.