I've heard reference in other questions on this site that seem to indicate a belief that Genesis was written by "the same man." What do we actually know about wrote Genesis (whether a single, or multiple authors)?
There are two theories:
Those are the two main theories. Unfortunately, we don't have any way of truly knowing who wrote Genesis. That's the reason for the varying theories.
Genesis/Exodus/Leviticus are a compilation of several narratives, all dating to the 10th century BC or thereabouts, which are evident by the seams in them, and by the radically different styles. They are considered to be compiling Jewish narratives to make a unified tale which will bring the disparate tribes together in a kingdom.
There are three major threads:
This author is first rate, one of the greatest writers in history, if not the greatest. She writes about God in a very visceral, fully embodied fasion. She tends to emphasize the stories of women, providing first person internal monologues from the point of view of Eve, Rebecca, Sarah, and provides a wonderful story of female attempted seduction in Genesis 39. For this reason, I refer to her as a "she", although this is obviously uncertain.
You can identify J easily by reading the narrative. There is no doubt when she is writing. She consistently uses "Yahweh" as God's name, or "Yahweh God" in Genesis 2. She writes internal monologue and easy natural dialogue. She tends to write stories of women in detailed human terms, and of men in distant heroic terms.
The quintessential Yahwist narrative is exemplified by the following passage in Exodus, chapter 33, verses 17, in my translation, available here :
The idea of seeing God's back, as He is moving away, lifting an enormous palm from a nook in the rock to uncover his mighty passing form, is simultaneously beautiful and haunting, and masculine erotic.
Elohist has a less fleshy description of God than J, and the drama is not as tense. Elohist writes about blessings and omens a lot. Here is some E (Genesis 48, in my translation, available on Wikisource ):
E uses "El Shaddai", which is a weird monicker for God. He also has the extraordinary "I am that I am" (more literally, "I'll be what I'll be"), which is followed by a Yahweh tack-on with an obvious seam.
Priestly can't write to save his life. He is almost surely a Levite priest, who is trying to canonize Leviticus law by attaching it to the timeless masterpieces produced by J and E. Priestly's voice is heard at the end of Exodus and throughout Leviticus.
A typical Priestly passage (Leviticus 11, vs 41-45) in my translation, available on Wikisource:
This block is particularly repetitive, but even this example does not do justice to Priestly's cloying, unnecessary, mind numbing repetitions. Things are a "comforting smell to Yahweh" six times in a chapter, detailed grilling instructions are repeated, detail by detail, three times for three only slightly different situations. Priestly is boring, uninspired, pedantic, and generally unreadable. One of the best things about Christianity is that you can ignore nearly everything he wrote.
Priestly is also the master of stilted narrative. Here is Leviticus Chapter 10 (my translation, on Wikisource) :
This is so stilted and badly written. Aaron's sons are immolated in his presence, and there is none of the drama of Lot running from the fire and brimstone, pleading with God to let him find shelter in a Mizar. None of the beauty and elegance of Jacob's pining for his lost son, prayed by wolves. No sign of the genius of pacing or drama of Genesis and the early half of Exodus. Their crime basically amounted to cooking communal meat on a grill different from the communal grill.
The only line of genius which can be safely attributed to Priestly is Leviticus 19:18 (in generic translation--- I went with "You loved your compatriot as yourself", but this phrase is famous.)
This is surely his, because it is embedded in a set of verses that repeat "I am Yahweh" for no good reason again and again and again.
The Redactor is whoever put the narratives together to make a whole. This is probably Priestly, the way I see it. You can see the redactor at work at several places, where verses are inserted for no reason other than the discomfort of the editor at what is being said.
consider Genesis 18, verses 16-22 in my Wikisource translation:
There is an obvious break in the otherwise extraordinarily beautiful narrative, coming right after "I disguise from Abraham that which I am doing." The thing that God wishes to disguise from Abraham is the destruction of Sodom and Gommorrah, but as the angels walk toward the city, Abraham argues with God about the destruction.
Anyway, redactor didn't like that God is diguising something from Abraham, and so stuck in the completely inane two verses that follow, which simply repeat promises of God to Abraham from other passages, which are completely out of context here.
Unlike other translations, the translation above seeks to preserve the tone-deaf narrative and horrible writing style of redactor, which match the tone-deaf narrative and horrible writing style of Priestly. I don't see any reason to think they are separate authors.
There is also the issue of the "and Aaron"'s in Exodus. These read more naturally if omitted, so that God is speaking to Moses only. But the Exodus author tacks on "and Aaron" in many places, some places where it mismatches with the singular tense of the verb! This is R at work, although I don't see any reason why this isn't P.
Arguing against identifying R with P is the fact that while common authorship of writing of great genius is easy to identify, all hacks of the same era write alike.
There is supposedly a D author, the Deuternomist, who continues the narration into Deuteronomy and perhaps Judges. I didn't translate those books, so I can't judge.
As for other authorial guesses, I think that the author of psalm 137 is also the author of lamentations, either in whole or in part. The word choice and the strange baby imagery is so distinctive.
Tradition says Moses compiled the book of Genesis, along with writing the rest of the Torah.
However from Wikipedia:
It is rather unclear who actually put the words to paper.
This Answers in Genesis article argues that Moses did indeed write Genesis:
The answers in Genesis article claims to prove this conclusively. However, I think the best we cay say is that we are unsure.