Buddhism is something (who can say what?) that is practiced, not rationalized.
Funny, I'd say the exact opposite. Well, not exact, in that there is a difference between rational thought and rationalization. In my view, the teachings of the Buddha -- the Middle Path -- are as close to rational as you can get in any non-material realm. But then, as the old saying goes, "A thousand monks, a thousand religions."
To return to the original post, the realms of existence are (from memory) as given below. Each realm is a reward (or punishment) for the previous realm.
The Hot Hells: everything returns to hurt or haunt you. Holgas, perhaps, or the Zone System?
The Cold Hells: you realize you don't need the Hot Hells and graduate to a point-and-shoot. It's still not much use but it's better than the Hot Hells.
The Realm of Animals: you understand that some things are better than others, and buy a camera you can control, such as a Zorkii.
The Realm of Hungry Ghosts: you then buy more and more second-rate cameras, but none of them satisfies your cravings.
The Precious Human Rebirth: you realize that life is not perfect, but resolve to make the best of it. A Voigtländer Bessa-R-series or second-hand Leica, perhaps.
The Realm of the Jealous Gods: you have all that anyone could want, but are paranoid about losing it: maybe a nice M-outfit that you are too frightened to use in case it gets scratched up or stolen.
The Realm of the Gods: everything seems to be perfect, but but you do not realize that because you are still in the realms of duality or illusion, this 'perfection' cannot last.
Sooner or later, in the Realm of the Gods, 'the garlands of flowers around your neck begin to wilt and your armpits begin to smell' -- and your new MP starts to feel rough. You fall back into:
The Realm of the Jealous Gods. You realize what you have lost; get paranoid; and fall back into the Precious Human Rebirth...
... and so on, eventually back down to the Hot Hells. Of course you can fall back into any lower realm at any point, without progressing to a higher one.
All of us are in one of these realms of existence. By definition, we are all in the Precious Human Rebirth at the moment (the most auspicious for recognizing the nature of illusion, balanced as we are between pleasure and pain) but within each Realm we can also perceive each other Realm, i.e. think of how you feel now and how you have felt in the past,
in this lifetime. Don't you remember being in the other Realms of Existence? Yesterday, maybe? Or last week? Or last month?
I apologize to any fellow Buddhists who think I am being flippant, and still more to those who know more about Buddhism than I and may have spotted a missed Realm; but I hope the examples may help a few people...
Cheers,
Roger