My reading of Julius Wellhausen's Prolegomena today covered some interesting issues. Much of my reading was about the contribution of P and J (or JE) to the Pentateuch (or, actually, one of the chapters was about the Hexateuch). Wellhausen indicates in parts of his book that he believes that the priest (and, by the way, he holds that there were two levels of P---one was the Book of Sources, and the other was the priest) worked with JE in front of him, and so he may think that P was one of the redactors, rather than an independent document that was linked with the other sources by another redactor. At the same time, Wellhausen also says that P had an ideology that contradicted elements of JE. For example, according to Wellhausen, P's creation story does not have a Fall, for he did not believe that children should be punished for the sins of their parents. Wellhausen differs from a professor of mine, who also thought that P added his own creation account to JE: for my professor, P, by doing so, was creating a story about a Fall, by presenting an ideal state from which Adam and Eve fell. For my professor, P was supplementing JE in this case, not seeking to undermine it.
I was interested in Wellhausen's discussion of the wilderness narrative, for I may have to answer again a question on my Bible comp about the wilderness, and, quite frankly, I did not entirely know the source criticism for the wilderness narratives the first time that I took it. I still don't know what source has the complaint stories---that's something that I may want to find out from Richard Elliott Friedman's Who Wrote the Bible?, for he offers his view as to who wrote what parts of the Pentateuch. But what I did get from Wellhausen is that JE presented Moses as a shepherd of Israel, who helped provide for God's people in the wilderness. E had the story of the Golden Calf, perhaps because the Elohist was a Northern priest who claimed descent from Moses, and so he wanted to undermine Aaron; moreover, "these are your gods," which occurs in the Jeroboam story, also appears in the Golden Calf story, and so the Elohist was probably speaking against Jeroboam's calves. (Wellhausen doesn't present these as motivations for the Elohist, but he just says that the Elohist wrote the Golden Calf story).
J had the story in which Dathan and Abiram revolted against Moses, perhaps to show how the tribe of Reuben fell; but P added Korah into the equation, making it a story about Levitical revolts against the one whom P deemed to be the legitimate priest, Aaron. P highlights the importance of Aaron throughout his contribution, whereas, at a certain stage of J, Aaron is not even a character. P also promotes the Sabbath through the manna story, confronts intermarriage through the story of the Midianite women, and does not lean heavily on war. According to Wellhausen, this reflects the exilic and post-exilic periods, when the priests tried to prevent assimilation, and when war was out of the question for Israel.
Another interesting point: In previous posts, I talked about Avi Hurvitz, who posited on the basis of P's vocabulary that P was pre-exilic (see, for example, here). But Wellhausen has the same tactic, only he notices words in P that occur primarily in exilic and later biblical books (e.g., raqia, q-t-r).