Borrowing themes from Mesopotamian mythology, but adapting them to the Israelite people's belief in one God,[2] the first major comprehensive draft of the Pentateuch (the series of five books which begins with Genesis and ends with Deuteronomy) was composed in the late 7th or the 6th century BCE (the Jahwist source) and was later expanded by other authors (the Priestly source) into a work very like the one we have today.[3] The two sources can be identified in the creation narrative: Priestly and Jahwistic.[4] The combined narrative is a critique of the Mesopotamian theology of creation: Genesis affirms monotheism and denies polytheism.[5] Robert Alter described the combined narrative as "compelling in its archetypal character, its adaptation of myth to monotheistic ends".[6]