Abstract
An examination of traditional sources for the Roman Catholic under-standing of marriage reveals that the ends of marriage might be ordered differently, given different contexts. This permits one working within that tradition to see marriage as a political and cultural entity existing independently of the individuals who participate in it. Marriage is also the standard with respect to which sexual activity is judged to be proper or not, a standard that applies to all human beings by virtue of their rational nature. Understanding this allows one to understand how some people, including some of the mentally handicapped, might legitimately be prevented from marrying and even from engaging in genital sexual activity. It also allows one to solve some theoretical difficulties regarding contraception and homosexuality and connected with the fact that sterile couples cannot procreate and yet are permitted to marry.