"Society does not consist of individuals but expresses the sum of interrelations, the relations within which these individuals stand."
So spoke Karl Marx, who spent a fair bit of time thinking about human civilisation and all its attendant joys and ills.
Had he been around in the time of commercial air travel we think he would have enjoyed the social experiment that is cramming a cross-section of society into a pressurised metal box hurtling through the sky for longer than is comfortable.
It goes without saying that this temporary microcosm has rules. So are you up to date on the laws of the sky?
1. Store your bags in the overhead cabin inconsiderately.
There's a lot of people and a lot of stuff.
2. Don't wear strong perfume or deodorant.
You're at very close quarters with a lot of strangers; overpowering scents can be as unpleasant as bad BO.
3. Don't try to join the mile high club.
Have you even thought about how filthy plane toilets get?
4. Don't tell off other people's children
If you have to say something, talk to the parents, not the kid - and parents, you may be knackered, but it's still your responsibility to make sure they're behaving.
5. Middle seat gets the armrests.
Dems the rules.
6. Check what the person behind you is doing before you recline your chair.
It's only polite - give them a chance to get hold of their drink and laptop first.
7. Don't get hammered.
It's a long flight, you're bored, sure, we get it. But won't somebody please think of the children?
8. Think ahead about when you're getting up.
Don't do it when the person next to you has just dropped off to sleep, and definitely don't do it before the food trays are collected.