This week I have been reading this book to see if there is any validity to the arguments for multiple sources. Reading this book as been an eye-opener to me. That people would actually buy into this, is beyond me. The author's of the Documentary Hypothesis don't believe Biblical history actually happened, they take a single story and document, split it up into four different documents, CHANGE IT so that they conflict with each other, and then they say that there was some mythical person long ago that took these mythical documents that they JUST CREATED, and did the exact opposite of what they just did to create a single harmonious document.
I have been told that the author's of the Document Hypothesis point out many contradictions in the text of the Torah, but as I have read about these contradictions, it has struck me that these contradictions don't exist in the Torah, they only exist in the mythical documents that they have created. Documents that don't exist, never have existed, there is not evidence they have existed. These atheists could not find a valid reason to do away with the Torah, so they created a set of "straw documents" they could tear apart to invalidate the Torah with.
That is my conclusion of the Documentary Hypothesis.
In short, total fabrication with no basis in reality.
Here is a link to a great article on the subject: Did Moses Write the Pentateuch?