"For the state to say, for example, that widespread access to certain kinds of guns might end up endangering the safety of people more than promoting the safety of people, therefore we're going to regulate to some degree what kinds of guns can be bought and sold, and under what kind of circumstances they can be bought and sold, I think that would be also absolutely in keeping with what the Church teaches," Miller said.
Petri added that the state is regularly entrusted to regulate other things that affect the common good, such as who is and is not allowed to own and drive cars, or who is allowed to distribute and obtain certain kinds of medicine.
"The thing is, when you talk about firearms, you're talking about a larger impact on the common good precisely because guns can be all the more harmful to others and to oneself than, say, simply driving a car," he said, the primary purpose of which is transportation.
"A car's normally used for getting around. Not a firearm," he said.
"A semiautomatic weapon is used for firing a lot of bullets very quickly, and what's the reason for that? Well, it's to do maximum damage to multiple targets at one time. So yes, I think Catholic moral principles would dictate that the state does have not only a right but a responsibility to monitor who has such means, and that they're in good mental condition and are able to use them properly."
A right to bear arms?
Another important thing to bear in mind when considering gun laws is that the founding fathers of the United States, who wrote the Second Amendment of the U.S. Constitution guaranteeing the right to bear arms, were largely following the principles of English Enlightenment philosopher John Locke, Petri noted.
Lockean principles dictated "that we basically exist as human beings in a state of violence, in a state of nature," Petri said.
But the Church views human nature differently, he said.
"The Catholic view is that human beings are not inherently violent towards each other. I mean, we are fallen creatures, but when we talk about rights, we're talking about it in the context of a community of friendship and common goals and a common life together."
Nowhere in its teachings does the Church state that people have "an inherent natural right to bear arms," Petri said, even though their legitimate use could fall under the principle of self-defense.
"I think it's a more than fair interpretation of (the principle of self defense) to say that it might include using guns," Miller noted.
Catholics who choose to not own or use guns or other weapons are morally permitted to do so, added Petri.
"There are Catholics who are absolute pacifists, (who believe) we shouldn't get into war, we shouldn't bear arms," he said. "I think especially with religious monks or religious sisters - they're classic pacifists. And we have examples, even in the last few years, especially in the developing world, of them just being killed. I mean, they're not going to defend themselves. So that is a legitimate position."
What the Church does not say, Petri added, is that the Church "is absolutely against the possession of firearms. I don't think you can go that far to the other side, because it's not a settled question. Possessing firearms is not an intrinsic evil. It's a prudential matter."
Owning a firearm is different than if one were to own a nuclear weapon, Petri noted. Weapons of mass destruction, such as nuclear weapons, are considered intrinsically evil by the Church, and there would likely not be a circumstance under which a person could legitimately and morally own them.
What should Catholics do?
Given that Church teaching allows for a lot of middle ground between two extreme positions on gun control, Catholics are to use their best prudential judgement when voting on gun policy or electing government officials, Miller said.
"Any Catholic who wants to take this into account when voting has to do what he or she reasonably can to inform him or herself regarding the evidence...on what kinds of gun control measures are or are not helpful in making communities and states safer rather than unsafe places," he said.
Because there is a "plethora" of sometimes conflicting studies and claims out there, this can prove difficult, Miller admitted, but Catholics must do their best to be "intellectually honest" and to take a serious look at the evidence surrounding gun policy when making these decisions.
"That doesn't mean people should simply throw up their hands...you have to give it your best shot in figuring out what experts in the field think make sense, and what they don't think makes sense," he said.
People should also take into account the different social and cultural circumstances of their region that relate to the use of guns, Miller added.
"I think what you have to do is be honest with yourself," he said. "Make a kind of mini examination of conscience. Ask yourself, 'Am I really doing my best not to be an idealogue or partisan about this? Am I really doing my best to try, based on the evidence that I have access to, to figure out what policies do and don't make sense?'"
Within those prudential decisions, there is room for disagreement, but there should not be room for Catholics to accuse other Catholics of violating Church teaching, Miller added.
"I think if a Catholic in good faith is making every effort to be intellectually honest in his reasoning, and stakes out a position almost anywhere between those extremes (of a total gun ban, or total unregulated access to guns), I don't think it would be right to say they are somehow taking a position that is explicitly contrary to the teaching of the Church," he said.
"You have to say, 'Ok, fair enough. Your prudential judgement might somehow be mistaken, but you're not somehow violating the teachings of the Church,'" he said.
Petri added that he agrees with other Church leaders, such as Archbishop Charles Chaput of Philadelphia, who have said that the solution to the crisis of mass shootings has to go beyond gun regulations or mental health interventions.
In his Aug. 5 column, Chaput wrote that while he supports background checks and restrictions firearms, "only a fool can believe that 'gun control' will solve the problem of mass violence."
"The people using the guns in these loathsome incidents are moral agents with twisted hearts. And the twisting is done by the culture of sexual anarchy, personal excess, political hatreds, intellectual dishonesty, and perverted freedoms that we've systematically created over the past half-century," he said.
"You've got to go deeper than that," Petri said, "and our culture is one that seems to glory in excessive violence, seems to promote excessive violence."
"It also seems to promote a throwaway culture in which those who are not wanted are not allowed to be born, and those who are a burden are increasingly pressured or encouraged by our culture to go away, which is to say, to get assisted suicide. So when you have a culture that doesn't seem to value life intrinsically anymore, it should be no surprise that we have these events happening."
He encouraged Catholics to consider what kinds of entertainment they support with their money, and to consider whether it glorifies violence or a "throwaway" culture.
"It's just a general cultural attitude. And nothing will change until enough people stop buying tickets or stop paying for these sorts of entertainments."
Mary Farrow worked as a staff writer for Catholic News Agency until 2020. She has a degree in journalism and English education from the University of Nebraska-Lincoln.