Speaking of an institution such as marriage as natural is, of course, paying it a compliment, the compliment of saying that it meets a fairly central human need. The fact that it is found in some form in every human society is in a way enough to show. But it might be thought that marriage became thus widespread only because it was, like adequate sanitation, a means to an end. This is pretty certainly what Hume thought, as evidenced by his very confused contrast of natural with artificial virtues. He regarded human sagacity simply as the power to calculate consequences, and counted chastity and fidelity, with justice, as artificial virtues, devices designed merely to produce safety and promote utility. In a species as emotionally interdependent as man this view of marriage is nonsense. Pair-formation could never have entered anybody's head as a device deliberately designated to promote utility.