In life, there are some topics of conversation that divide people into factions like no others: war, religion and politics are three that spring to mind.

But after a few recent incidents that have been widely reported in the media, we can now add reclining your seat on an airplane to that list.

Evidently, people will go to great lengths to defend their position on seat reclining and even greater lengths to convince others to join their side in the fight.

On the one hand, you have the pro-recliners, or at least those who are pro-reclining choice.

Those seats are built to recline, so it’s the passenger’s prerogative to use that ability or not, the argument goes.

On the other hand, you have the anti-recliners, the ones whose growing anxiety at having a seat back inch closer to their knees makes the blood rise to just below the surface of the skin on their faces and the steam begin to whistle from their ears.

This second person is perhaps liable to invest in the Knee Defender, a $20 gadget designed to slide down the arms of your lowered tray table and jam the seat in front of you, preventing it from reclining.

The product has been on the market since 2003, but recently shot to infamy after an American businessman used them on a United Airlines flight on Aug. 24.

When the woman in front of him could not recline her seat, the two had a nasty spat that included her allegedly throwing a drink in his face and the pilots actually diverting the plane from its original destination of Denver to Chicago.

While it’s a sneaky design, the device gives rise to what is perhaps the great debate of our time: who does that space between the knees of one person and the seat back of the next belong to?

There is merit in both arguments.

Sometimes on a long flight, you just want to make yourself an iota more comfortable.

Sometimes you’re in front of a tall person and you don’t want to bang your seat into their knees.

Sometimes you’re the one who’s leaned on and you’re the middle domino in a line of reclining passengers.

If I’m not leaned on, then at worst I’m a halfway leaner.

If the seat behind is vacant, why not? I say go crazy and recline that puppy all the way if that’s what suits your mood.

Above all, if the person behind you requires average or more than average leg room, it’s simple courtesy to be mindful of the people around you. You are, after all, stuck with them for perhaps hours inside a metal tube suspended 30,000 feet in the air. It’s probably best not to make trouble in such a delicate situation.

The passive-aggressive route of the Knee Defender and the aggressive-aggressive route of throwing a drink in someone’s face did not pan out well in this scenario.

People will do all kinds of things that you’ll find irksome throughout your lifetime, but many of those things are a matter of how big of a deal you make them.

As much as you should choose your battles, you should probably also choose what you let really tick you off.

In a year, you probably won’t remember that time you flew for three hours while the person in front of you reclined as luxuriously as economy air travel will allow.

But you might remember for a long, long time if you block them and get a drink in the face.

And if reclining fliers is one thing you just can’t get over, try just using your words.

I say it’s best to not let your blood pressure rise or, heaven forbid, boil over into an eruption of rage at something that is really only an inconvenience for a few hours of your life.

Even if we can never all agree on reclining etiquette, perhaps we can all agree that there is simply not enough legroom to go around in economy cabins.