Should mention, sumerian (and other contemporary civiliastations) mythology is the subject i referred to, there are probably better sources (books even.....) than wiki, obviously.
But when you refer to "intellectual" basis, i figure you actually mean an archeological, or otherwise scientific study of its basis, not theology.
You have practically all of the basic plot samples of the bible, lifted or abstractly plagiarised from earlier cultures.
Adam and eve? Possibly an abstraction of gilgamesh, (though i gather there are much earlier versions), there cant have been that many pines on cypress, maybe an elaborate (yet primitive) essay on deforestation, who knows.
Noah, the flood? Same.
Eye for an eye? Lifted directly from hammurabi, though its entirely likely many cultures would have similiar law, due to its being so remarkably stupid.
Hebrew jehovah? An amalgamation of numerous other gods, given creedence by the force of Akhenaten's monotheism, though widely unpoular at the time.
The sumerians, wore a traditional dress of a sheepskin skirt, and many of their unearthed "spiritual" representations contain-wait for it-horns.
Short of the actual cloven feet, you have right there, an image of both the greek pan, and later variations of the devil as a pan like trickster (or similiar) , in various modified versions.
They also, according to archeological evidence, were among the very first dam builders, diverting the euphrates to their ends-though its practically a given, the early egyptians attempted much the same thing, but sooner, or later? Either way, they were the first known large scale irrigators, so its entirely plausable either total ignorance or inexperience could have led to various flooding and famine, easily, resulting in any number of extra gods(or even a single god, because some of them didnt do their job) and myths.
Its critical, to consider how many people of the time were actually literate,(and in which language) and who exactly was writing these texts.
