This second part of a two-part series exploring implications of the natural differences between the sexes for the cultural evolution of marriage considers how the institution of marriage might evolve, if Kant’s reasons for defending monogamy are extended and applied to a future culture. After summarizing the philosophical framework for making cross-cultural ethical assessments that was introduced in Part I and then explaining Kant’s portrayal of marriage as an antidote to the objectifying tendencies of sex, I summarize Kant’s reasons for (...) rejecting polygamy and for viewing monogamy as the only ethically acceptable form of marriage. Finally, I argue that if we apply Kantian principles to the real situation of marriage in many modern cultures, and if we wish to maintain a legitimate place for marriage in the future evolution of human culture, then the future evolution of marriage laws must recognize polyfidelity (i.e., plural marriages for both men and women) as being just as legitimate as monogamy. (shrink)

This article begins the task of assessing polygamy as a moral ideal. The structure of traditional polygamy, in which only one central spouse may marry multiple partners, necessarily yields two inequalities. The central spouse has greater rights and expectations within each marriage and greater control over the wider family. However, two alternative structures for polygamy can remove these inequalities. In polyfidelity, each spouse marries every other spouse in the family. In “molecular” polygamy, any spouses may marry a new spouse (...) outside the family. These new models of polygamy face additional difficulties, but they can be egalitarian in principle. (shrink)