"The assertion that the Jacob/Esau story is a parable also needs to be supported. It is certainly unlike most/all other Biblical stories known as parables. Perhaps "folktale" would be more appropriate if one rejects the story's historicity, and such rejection would also require support. There aren't even many elements of the supernatural for a naturalist to reject a priori."

OK, yes, that is a better term, I think, thank you, FlemGem.

A folktale...I was going with parable because I think it also is designed to give a good/bad lesson, but i suppose you can have that with a folktale as well, so yes, perhaps that's a better term.

"The text expects you to consider him a real person, and infer his characteristics from his actions. Like every text."

But he has so few actions and so little to say that you can justifiably only infer very little or, to put it better, perhaps, the amount of things you may infer is severely limited, and so his depth is limited.

You simply cannot turn a flat character textually into a round one on inference alone...

NOW, if you're ADAPTING the story, that's different; I think I've said it before, but I think that the adaptations of the Exodus story are better than the written thing because they do just that, they adapt and expand and thus infer more material into the characters, and develop the Pharaoh into a more complex villain (and hero/villain conflicts can only be better when the villain is complex as well as the hero, and I'd certainly agree Moses is a complex hero, I have no disagreement there) and so on...

But that's adapting the text to tell the story you want to see, NOT inferring what you want to see into the original text ITSELF, that strikes me as being--for lack of a better word--unfaithful and not true to the text.

Hamlet's a bit too complex already for this too work (he's one of the most well-developed characters in English literature, after all, so you can and people have read hundreds of different things in with textual support for hundreds of years), so to use another case to illustrate my point here...

Take, say, Marcellus, aka, the guy who sees the Ghost of Hamlet's Father first and gets to be played by Jack Lemon in the star-studded 4-hour Branagh version. :)

Marcellus is a flat character.
He has very few lines.
He has very few actions.
He is really mainly just a plot device to see the Ghost and get things going for Hamlet.

That's about it.
I couldn't infer, justifiably, much else into his character...
I couldn't say whether he was a wrathful or kindhearted person...
Gay or straight...
What his hopes and dreams might have been...

There's only so much you can justifiably read into his character.
In terms of lines, I THINK--I may be a bit off, not putting them side to side, but I think--Marcellus is close to (definitely in the ballpark of) the amount of lines Esau gets.
What's more, "Hamlet," for as long as it is, being WAY shorter than the Bible, Marcellus' presence actually has a higher ratio of lines in the overall story than does Esau.

We can't argue that he's just a porter and does nothing important, he does--he sees the Ghost after all...and if it had just been Hamlet seeing the Ghost, we might have then just decided that it was all in his head, since he can see it but not his mother in Act III Scene 4, but as Marcellus sees it before Hamlet's even on the scene, we have a legitimate question as to whether or not it's real.

So he has a function, just like Esau has a basic story function...

But both end there, really, they' ONLY have basic story functions and are only flat characters.

There is nothing in Marcellus' lines that you could use to construe poetically to give his character extra meaning; sometimes of course the Bible and Shakespeare WILL have a minor character you can read a lot more into--sticking with Hamlet, the role of the Gravedigger comes to mind--than you might think for the role, but THAT is because of the poetic quality of their lines...

The Gravedigger and some minor Biblical characters SAY THINGS that are deep or puzzling or profound or raise an important point--ie, the Gravedigger's talking about the nature of death and the logic and morality of suicide vs. accidental deaths--and so they have more depth than they may seem to have at first with their limited amount of lines...

But this is not the case for Marcellus, nor may we say it is the case for Esau.

Esau bemoans his situation, but that's not especially "deep;" it may be moving, if you feel he was wronged (and he WAS roundly screwed) but it's not deep or profound or unique or anything of that nature.
None of his lines are especially poetic, and we know poetic from non-poetic lines in the Bible, the Book of Job and the Psalms are famously some more poetic lines and works...here it is neither structurally nor tonally poetic.
There is little DEPTH to what Esau says or does or feels, its all one-dimensional.
By contrast, Marcellus is the same, one-dimensional in what he says/does/feels...
But the Gravedigger, while one-dimensional in what he does and maybe even what he feels, is not at all one-dimensional in what he SAYS, he's giving multi-layered riddles and thinking them over and working his way through these ideas with his friend and then later with Hamlet.

As such, it's FAIR to infer a bit more character into the Gravedigger, the content of his lines warrants it.
But it's not really fair to do so with Marcellus or Esau, with one exception, I'd say--

If you are an ACTOR, then yes, you DO have to infer something about their background and make up a backstory and everything to play this little part effectively, that's an old acting technique, and it makes sense, you can't try to play even a small character with conviction without doing so...

But that's just for the actor's personal use, that's not saying those backgrounds are inferred by the text itself, or supported by it, that's closer to adaptation and just making up your OWN backstory to suit your own vision.

"But, without any support whatsoever, you asserted that the story of Jacob and Esau is "flat because the story is essentially part-parable, and, well, parables generally DO feature flat characters."

1. I gave support BESIDES likening it to a parable, Mujus...the lack of lines, the limited content of the lines, the limited structure of the lines, the lack of poetic structure or content in those lines, the ratio issue I mentioned, etc. so I gave a LOT of other support besides that
2. Like I said above, I think FlemGem had a better term for it with folktale; folktale or parable, though, both generally lack depth...after all, when I think of a folktale, I think of, say, Paul Bunyan, and that's not exactly a story with tons of depth.