It is commonly said that polygamy was customary among the Peruvians; but this statement may be strongly doubted. It is entirely true that the nobles had large seraglios; but, when the open concubinage that was a prerequisite, as it were, of royalty is taken into consideration, together with the fact that polygamy was not known among the common people, it is far more likely that the real custom was that of open and legal concubinage rather than true polygamy. The confounding of nearly related facts in this wise is too common to make us chary of attributing such confusion; even to this day many well-informed writers are given to stating that polygamy among the Mussulmans is unrestrained, whereas no Mussulman can have more than a fixed and small number of wives, all the other women in his harem being merely legal concubines. Because of this rashness of statement as well as of the difficulty of ascertaining the precise facts in regard to Peruvian domestic polity, we may assume that monogamy was the legal custom, with a recognized concubinage as the privilege of the nobility as well as of the monarch, since this theory best consorts with the facts as we know them. Be this as it may, there is no doubt that among the Peruvians, speaking of them in general and not as divided into classes and castes, domesticity was on a plane fully equalling that known to any of the primitive cultures of America or even of Europe. Marriage was regarded as a sacred relation, and adultery was considered one of the most heinous of crimes, being punishable with death. In this and other places, however, it must be borne in mind that in speaking of the old Peruvian civilization, the word "punishable" is necessarily used instead of the more positive "punished"; for it does not seem that all the laws were straitly enforced. It was, for example, a singular provision of this law that made no distinction between adultery and fornication, both being equally visitable by death; yet there was a recognized, if not legalized, system of prostitution in the cities of the Incas. Such a contradiction of facts casts a very grave suspicion upon the integrity of the whole of the code in which that contradiction appears; and it may therefore be supposed that much of the legislation of the Incas was allowed to remain a dead letter. Still, the tendency of thought among a people can frequently be discovered by a study of their statute-book, even if the laws be not implicitly enforced; and we may judge from the laws of the Incas that the people over whom they ruled were straitly moral according to their lights, which is all that can justly be demanded of any people, even the most civilized.