allowed in others. You can predicate nothing of either excepting that each society deems its own practice to be upon the whole the most advantageous. You can not say that there is any fixed law of nature which renders it unnatural for one man to have more than one wife. In many ages of the world there have been states of society in which the family has had as good a foundation in polygamous as it has had in monogamous unions. Looking, then, at these undeniable facts, and also at the fact that marriage, whether monogamous or polygamous, is an institution regulated by human law and custom, we have to inquire for the reason why human law and custom take any cognizance of the relation. We find that, among some of the other animals, the sexes do not pair excepting for a single birth. The connection lasts no longer than for a certain period during which the protection of both parents is needed by the offspring, and not always so long even as that. It has become the experience of mankind that the connection of the parents ought to be formed for more than one birth; shall be of indefinite duration; and this because of the physical and social benefits which flow from such a permanency of the union. This has given rise to certain moral feelings concerning the relation of husband and wife. But we have no more warrant, from anything that we can discover in nature, for regarding the permanency of marriage among the human race as a divine institution than we have for regarding its temporary continuance among the other animals as a divinely appointed temporary arrangement. In the one case, the permanency of the union has resulted from experience of its utility. In the other case, the animal perceives no such utility, and therefore does not follow the practice. Upon the hypothesis that all the animals, man included, had a common origin, it is very easy to account for the difference which prevails between man and the other animals in this matter of marriage, or the pairing of the sexes. As man became by insensible gradations evolved out of some pre-existing organism, and as moral sentiments became evolved out of his superior and more complex relations with his fellows, from his experience of the practical utility of certain kinds of conduct and practice, the sentiments became insensibly interwoven with his feelings about the most important of his social relations, the union of the sexes in marriage. This is quite sufficient to account for the difference between man and the other animals in regard to the duration of such unions, without resorting to any intentional or divine or superhuman origin of that difference.