they were to retain the respect of the community, it was necessary to place them on a new theoretical basis. That basis, in accordance with the general advance of thought, was supplied by religion. Sexual relations which had once been condemned as wrong and unnatural because they were supposed to thwart the natural multiplication of animals and plants and thereby to diminish the food supply, would now be condemned because it was imagined that they were displeasing to gods or spirits, those stalking-horses which savage man rigs out in the cast-off clothes of his still more savage ancestors. The moral practice would therefore remain the same, though its theoretical basis had been shifted from magic to religion. In this or some such way as this {102} we may conjecture that the Karens, Dyaks, and other savages reached those curious conceptions of sexual immorality and its consequences which we have been considering. But from the nature of the case the development of moral theory which I have sketched is purely hypothetical and hardly admits of verification. [Sidenote: But the reason why savages came to regard certain sexual relations as irregular and immoral remains obscure.] However, even if we assume for a moment that the savages in question reached their present view of sexual immorality in the way I have surmised, there still remains the question, How did they originally come to regard certain relations of the sexes as immoral? For clearly the notion that such immorality interferes with the course of nature must have been secondary and derivative: people must on independent grounds have concluded that certain relations between men and women were wrong and injurious before they extended the conclusion by false analogy to nature. The question brings us face to face with the deepest and darkest problem in the history of society, the problem of the origin of the laws which still regulate marriage and the relations of the sexes among civilized nations; for broadly speaking the fundamental laws which we recognize in these matters are recognized also by savages, with this difference, that among many savages the sexual prohibitions are far more numerous, the horror excited by breaches of them far deeper, and the punishment inflicted on the offenders far sterner than with us. The problem has often been attacked, but never solved. Perhaps it is destined, like so many riddles of that Sphinx which we call nature, to remain for ever insoluble. At all events this is not the place to broach so intricate and profound a discussion. I return to my immediate subject.