Human beings only have two ways to deal with one another: reason and force. If you want me to do something for you, you have a choice of either convincing me via argument, or force me to do your bidding under threat of force. Every human interaction falls into one of those two categories, without exception. Reason or force, that’s it.
In a truly moral and civilized society, people exclusively interact through persuasion. Force has no place as a valid method of social interaction, and the only thing that removes force from the menu is the personal firearm, as paradoxical as it may sound to some.
When I carry a gun, you cannot deal with me by force. You have to use reason and try to persuade me, because I have a way to negate your threat or employment of force.
Guns themselves, of course, aren’t civilizing. But an independent society that embraces the private ownership of guns is civilizing. Mostly because it’s hard to oppress an armed citizenry, and so things like debate and free speech are a must.
The founders understood this (even if a lot of people today don’t) and thus included the 2nd amendment in the Constitution as a last-ditch defense against tyranny. If all else went bad and America was to become run by tyrants they figured that the private possession of guns would give citizens a way to win their country back.
We were once a nation of citizen soldiers, and we’ve strayed way too far from that ideal.