Frances Dolan, a professor of English at the University of California, Davis, says Valentine's Day is a perfect opportunity for lovers to re-envision romance -- especially the notion that in an ideal romance, two become one.

"The trouble with two becoming one is that, historically, it has led to conflict about which one," says Dolan, author of the book "Marriage and Violence." In it, Dolan looks at disastrous love matches in history and popular culture, including Anne Boleyn's fatal marriage to Henry VIII, Shakespeare's "The Taming of the Shrew," and the 1991 movie "Sleeping With the Enemy."

But marriage doesn't have to be a process of friction and loss, in which one spouse absorbs, subordinates or even eliminates the other, Dolan argues. It can be a relationship of equals.

"That's the next horizon," she says. "As a society, we haven't gotten there yet. I think we are only on the brink of really imagining the erotic and emotional possibilities of equality in marriage."