But Judge Walker, who will decide the case, dogged Mr. Cooper for hard evidence of that claim, noting that there are no rules prohibiting marriage between people who cannot have children.

Over the course of several hours, Judge Walker also sharply questioned the qualifications of one of Mr. Cooper's witnesses and his assertion that marriage ''serves a societal purpose that is equally ubiquitous.''

At one point, Judge Walker wondered at Mr. Cooper's logic. ''Do people get married to benefit the community?'' he asked. ''When one enters into a marriage, you don't say, 'Oh boy, I'm going to benefit society!' ''
