The controversy over gay marriage and civil unions has sparked a larger debate over the nature of marriage and its role in U.S. society. How would changes to marriage laws impact society's views of marriage? Would civil unions be a reasonable compromise? What roles do the government and religion play in the institution?

To further explore these issues, the NewsHour posed questions at the heart of the debate to four experts with divergent views on gay marriage. Gary Buseck, legal director at the gay rights group Lambda Legal; Dwight Duncan, associate professor at Southern New England School of Law; Thomas Kohler, professor at Boston College Law School; Andrew Koppelman, professor of law and political science at Northwestern University; Brad Sears, executive director of the Williams Project on Sexual Orientation Law at UCLA; and Peter Sprigg, director of marriage and family studies at the Family Research Council, responded to those questions.