Our views about marriage are multifaceted, and the primary facets are two. On one hand, we think marriage has something to do with reproduction and its consequences; on the other, we think it has something to do with the experience of two people who are in love.

Opponents of same-sex marriage think the law should concern itself only with the first facet and must not define marriage other than in terms of its orientation toward procreation. I think the law has a legitimate interest in both facets and can reasonably address the public-policy considerations related to each.

I will call that position …