The Bishops are not advocating gun bans, but gun control and their line is supported by the Vatican:
uscatholic.org/news/2011/01/gun-control-church-firmly-quietly-opposes-firearms-civilians
*The Vatican’s justice and peace council is working to update its 1994 document, “The International Arms Trade,” to further emphasize the importance of enacting concrete controls on handguns and light weapons, he said.
The current document calls on every nation and state “to impose a strict control on the sale of handguns and small arms. Limiting the purchase of such arms would certainly not infringe on the rights of anyone.”
The more weapons there are in circulation, the more likely terrorists and criminals will get their hands on them, the document said.
The Catholic Church recognizes that “states will need to be armed for reason of legitimate defense,” as Pope Benedict XVI said in a message to a Vatican-sponsored disarmament conference in April 2008.
However, armed defense is something appropriate for nations, not for all individual citizens in a state where rule of law is effective, said Di Ruzza.
According to the Catechism of the Catholic Church, individuals have a right and a duty to protect their own lives when in danger, and someone who “defends his life is not guilty of murder even if he is forced to deal his aggressor a lethal blow.”
How that “lethal blow” could be licitly wielded is unclear, but the catechism clarifies that repelling the aggressor must be done “with moderation” in order to be “lawful” in the eyes of the church; using “more than necessary violence” would be unlawful, it says.
According to the catechism,
the right to use firearms to “repel aggressors” or render them harmless is specifically sanctioned for “those who legitimately hold authority” and have been given the duty of protecting the community.*
Dr Ruzza said that in “a democracy, where there is respect for institutions (of law), the citizen relinquishes his right to revenge onto the state,” which, through its law enforcement and courts system, aims to mete out a fair and just punishment.
“There is a sort of natural right to defend the common interest and the common good, and in 1791 (when the United States passed the Second Amendment), my right to have a weapon served the common good because there wasn’t an army; the democratic institutions were young and a little fragile, and I could have been useful in a time of war as a soldier,” said Di Ruzza.
But once a nation has a functioning army, police force and court system, “do I still serve the common good with my gun or do I put it at even greater danger?” and promote a lawless kind of “street justice where if you steal my car, I shoot you,” he asked.