The horrific massacre in Newtown, Conn., is reigniting the debate over guns — which must begin with the realistic premise that there will never be a gun-free America. Until we own up to this truth, we won’t get anywhere.

An emotional revulsion toward guns inhibits productive dialogue between gun-control advocates and their opponents. For many gun-control supporters, a good world is one where private ownership of guns is both unnecessary and illegal.

I have sympathy for the appeal of this ideal, but such a daydream cannot guide our public policy.

There are approximately 300 million guns in private hands in the United States. Even if the government enacted a massive program to confiscate these weapons, the feds would fail in their task and frighten millions of Americans in the process.

And if they did somehow manage to take away legal weapons? That would still leave criminals happily armed.

We must simply accept the inevitability of an America teeming with guns (to the chagrin of Piers Morgan and his fellow liberals). If we at least agree on this realistic starting point, we can move the debate toward reasonable and effective policy proposals: better mental-health care to prevent seriously ill people with violent tendencies from acquiring weapons; background checks; better enforcement of existing laws.

None of these need to involve taking guns out of the hands of law-abiding Americans in order for us to avoid the next Newtown. In fact, guns may well help prevent it.

In December 2007, for example, Matthew Murray entered the New Life Church in Colorado Springs, Colo., armed with two handguns and an assault rifle (the same arsenal possessed by Adam Lanza). Murray had killed two people in the parking lot before entering the church. Inside, he shot one man in the arm before being shot by Jeanne Assam, a former police officer with a concealed-carry permit.

Potential massacres were also stopped in 1997 at a Pearl, Miss., school and in 1998 at a school dance in Edinboro, Pa. In both cases, responsible citizens prevented mass bloodshed by drawing their weapons and using them for the public good. Mock the NRA’s Wayne LaPierre all you want, but in those two cases — and plenty of others — good guys with a gun did save the day.

Forty-one states currently have safe and effective concealed-carry permitting systems, and eight other states have more restrictive discretionary permitting laws. Since the 1980s, there has been a profusion of states that allow concealed carry and — despite the dire predictions of many — there has been no corresponding increase in crime rates.

Permit holders are not having parking-lot shootouts or brandishing their weapons during mall scrums over toys. In the past 20 years, the cases of permit holders using their guns improperly are quite rare — and they are certainly much rarer than the times in which people used a concealed weapon to successfully defend themselves.

In short, we have become a society that allows widespread gun-carrying for law-abiding citizens, and this has occurred largely in silence not because of political pressure by the gun lobby or cowardice by Democrats but because there is almost nothing to report.

Almost nothing. We have been mostly silent about just how many times Americans use guns to lawfully and successfully defend themselves from crime.

At minimum, according to the Justice Department’s own data, this occurs about 110,000 times per year.

There are, however, many reasons to suspect that this data severely under-reports the true number; other studies have found that Americans use guns defensively between 830,000 and 2.45 million times per year.

Moreover, these numbers don’t include the inherently immeasurable instances where would-be criminals decided not to commit a specific crime due to the fear that the would-be victim might be carrying a gun.

In the wake of the Newtown tragedy, stricter gun laws will almost certainly be proposed. But if we make the reasonable assumption that criminals will evade these laws if at all possible, and that identifying shooters before their crimes is a monumentally difficult task, then we can start to deal with actually attainable, second-best solutions.

While we should do everything we can to prevent massacres like Newtown, we should also remember what it takes to stop a New Life Church.