THE national conversation about guns, since James E. Holmes shot 12 people to death and wounded 58 others at a movie theater in Aurora, Colo., has been a dialogue of the deaf. Unless gun-control advocates and gun-rights supporters stop screaming at each other and look for common ground on how to deal with gun violence, the next massacre is only a matter of time.

Liberals have to deprive the National Rifle Association of its core argument, that the real aim of all gun control measures is to strip Americans of their right to have and use firearms. Gun-control supporters must make clear that they accept that Americans have had this individual, common-law right since Jamestown and the Plymouth Colony; that this right was recognized in the Second Amendment to the Constitution in 1791; and that the Supreme Court affirmed its constitutionality in 2008. Liberals should accept that the only realistic way to control gun violence is not by keeping guns out of the hands of as many Americans as possible, but by keeping guns out of the hands of people we all agree should not have them.

Gun owners and their advocates must, in turn, stop insisting that gun ownership is an absolute right. The Second Amendment is not a law unto itself. Before and after 1791, the right to keep and bear arms has been inseparable from civic responsibility: originally, the duty to answer a call to carry arms in defense of community or country, as part of militia service. Today — with 30,000 firearms deaths a year (half of them suicides) — the civic duty is to find ways for gun ownership and public safety to better coexist. Yet the N.R.A. continues to act as if gun owners have no responsibility to anyone but themselves and their families.

So far, liberals and centrists have done more to adopt a reasonable position. The president of the Brady Campaign to Prevent Gun Violence has lately begun to emphasize that it accepts the Supreme Court’s ruling on the Second Amendment (which also upheld “longstanding prohibitions” on gun ownership by felons and the mentally ill, and gun bans in schools and government buildings).