[W]hat, in the last analysis, makes sense of the conditions of the marital enterprise, its stability and exclusiveness, is not the worthy and delightful sentiments of love and affection which invite one to marry, but the desire for and demands of a procreative community, a family.
(John M. Finnis, "Natural Law and Unnatural Acts," chap. 1 in Human Sexuality, ed. Igor Primoratz, The International Research Library of Philosophy 19, ed. John Skorupski [Aldershot, England: Dartmouth Publishing Company, 1997], 5-27, at 23 [italics in original] [essay first published in 1970])