Whenever there’s another mass shooting in America, like the massacre in San Bernardino last month, I think immediately of my Uncle Bill in Texas, a retired military man, practising Catholic, Republican, NRA member, community volunteer and civil libertarian who lives in a gated community with my Aunt Bev (a retired nurse) on the outskirts of Houston. Uncle Bill likes to email me redneck jokes in the hope of getting my progressive Canadian dander up. Here’s a recent one:

“ The premier of Ontario is jogging with her dog along a nature trail. A coyote jumps out and attacks the premier’s dog, then bites the premier. She calls animal control. Animal control captures the coyote and bills the province $200 testing it for diseases and $500 for relocating it. She calls a veterinarian. The vet collects the dead dog and bills the province $200 testing it for diseases. The Liberal party spends $2 million to study how to better treat rabies… etc., etc.

Meanwhile, the governor of Texas is jogging with his dog along a nature trail. A coyote jumps out and attacks his dog. The governor shoots it with his state-issued pistol and keeps jogging. The governor has spent 50 cents on a .45 ACP hollow-point cartridge. The buzzards eat the dead coyote.

And that, my friends, is why Ontario is broke and Texas is not.

Or it could be oil, I think.

But what about this scenario, I recently wrote back to Uncle Bill: a young mentally ill teenager is having fantasies about killing himself and his entire class. In Canada (or the UK, or anywhere in western Europe) he’d receive state-funded healthcare and get better. In America he could simply go to Walmart and buy a semi-automatic weapon and enact his fantasy. And that is why the school-children of Canada (or the UK, etc.) are safe and those of Texas are not.

Uncle Bill and I have a respectful discourse. We agree to disagree, as polite people say. And although we have corresponded thoughtfully and extensively over the past few months, the chance of either of us altering position on gun control is small. According to the latest science, progressives and conservatives have different levels of personality, psychology, and even traits like physiology and genetics that affect our cognitive biases, i.e., the way we interpret events like terrorist attacks and mass shootings. For someone like me, a mass shooting like Sandy Hook, in which 20 tiny schoolchildren were slaughtered by the madman Adam Lanza, is a clear reason for sensible gun legislation. I’m with Obama, who teared up on Thursday just thinking about Sandy Hook, and vowed to tighten gun laws. But for a conservative like Uncle Bill, it’s an obvious argument for the importance of American civil liberties and gun ownership.

American writer David Robertson wrote recently in Vox magazine: ‘To the gun owner, another mass shooting is not an argument for getting rid of guns. It’s a confirmation of his every instinct, another sign of moral and societal decay, another reason to arm himself and defend what he’s got left.’

This has been the revelation of my correspondence with Uncle Bill: we believe in the same things (life, liberty, equality and all that other nice French stuff) but we see very different routes for our respective societies to safely arrive at it.

A couple of years ago Uncle Bill’s children, my cousins Patty and Billy Jnr, gave their dad the money for his first ‘conceal and carry’ licence for his birthday. They did this not because they were hoping he might put a cap in someone’s ass for fun, but because they were worried about their ageing parents’ safety and felt the best way to safeguard it was to ensure their father carries a gun with him 24/7 when he is not at home being guarded by armed security. To his credit Uncle Bill and my Aunt Bev did a gun-safety course but decided not to buy a weapon (they don’t keep a gun in the house either), but they would defend anyone’s right to do so.

The prevailing wisdom is that conservatives are more realistic than liberals, their vision more pragmatic, their eyes unpeeled to the awful truth. And in some ways that’s true. But when it comes to American gun owners, there is instead a deranged sort of innocence — the sort of thinking that occurs when you take a perfectly good ideal (freedom, say, or safety), mix in a large helping of irrational fear, then spin it to its logical conclusion. Uncle Bill’s belief in the Second Amendment, like many Americans’, is like a religious faith in the notion of independence — the belief that when it comes right down to it, if the world goes to hell, a man should at least have the right to defend his own family and property. Like all ideals it is kind of beautiful, but it’s also quite mad.

The comedian Bill Maher once likened the experience of arguing with American conservatives as akin to getting your dog to take a pill. ‘You have to feed them the truth wrapped in a piece of baloney, hold their snout shut, and stroke their throats. Even then, just when you think they’ve swallowed it, they spit it out on the linoleum.’

Especially when it comes to the emotional issue of gun control, Republicans like Uncle Bill are as startlingly fact-resistant and reason-impervious as a mutt who will always follow his instinct over rational sense.

The left-wing film-maker Michael Moore predicted on his blog this year that when and if the crime-scene photos of Sandy Hook are ever leaked to the public, Republicans would be forced to let Obama pass the gun legislation he so desperately desires. ‘When the American public sees what bullets from an assault rifle fired at the body of a child can do the jig will be up for the NRA.’

This is utter nonsense, of course. Most NRA members would be far more likely to support Republican hopeful Ben Carson’s position that the best prevention for school shootings is to arm kindergarten teachers.

I began my dialogue on gun control with Uncle Bill in the hope that I could bring him round to my point of view through rational, fact-based argument, but I’ve now realised that this is simply not the way proponents of the Second Amendment think. Their thought processes are a closed loop best described by a brilliant headline in the Onion: ‘no way to prevent this,’ says only nation on earth where this ever happens.

I adore my Uncle Bill and while I know I will never change his mind, at least I have gained an understanding into why. You can wrap the truth in as much baloney as you want but if the dog is truly stubborn you’ll never make him swallow it. At least in Texas you could put the poor beast out his misery. I’ll give him that.

To the gun owner, another mass shooting is another reason to arm himself and defend what he's got left

We’ll never agree. But I do understand him better now