Before Wellhausen
The traditional view that Moses was the author of the Torah came under increasing and detailed scrutiny in the 17th century. In 1651 Thomas Hobbes, in chapter 33 of Leviathan, cited several passages, such as Deut 34:6 ("no man knoweth of his sepulchre to this day", implying an author living long after Moses' death); Num 21:14 (referring to a previous book of Moses' deeds); both, according to the Latin based translation and Gen 12:6 ("and the Canaanite was then in the land", implying an author living in a time when the Canaanite was no longer in the land); and concluded that none of these could be by Moses. Others, including Isaac de la Peyrère, Baruch Spinoza, Richard Simon, and John Hampden came to the same conclusion, but their works were condemned, several of them were imprisoned and forced to recant, and an attempt was made on Spinoza's life.
In 1753 Jean Astruc printed (anonymously) Conjectures sur les mémoires originaux, dont il paraît que Moïse s'est servi pour composer le livre de la Genèse ("Conjectures on the original accounts of which it appears Moses availed himself in composing the Book of Genesis"). Astruc's motive was to refute Hobbes and Spinoza – "the sickness of the last century", as he called their work. To do this, he applied to Genesis the tools of literary analysis which scholars were already using with Classical texts such as the Iliad to sift variant traditions and arrive at the most authentic text. He began by identifying two markers which seemed to identify consistent variations, the use of "Elohim" or "YHWH" (Yahweh) as the name for God, and the appearance of duplicated stories, or doublets, such as the two accounts of the creation in the first and second chapters of Genesis and the two accounts of Sarah and a foreign king (Gen.12 and Gen.20). He assigned verses to ruled columns, the "Elohim" verses in one column, the "YHWH" verses in another, and the members of the doublets in their own columns beside these. The parallel columns thus constructed contained two long narratives, each dealing with the same incidents. Astruc suggested that these were the original documents used by Moses, and that Genesis as written by Moses had looked just like this, parallel accounts meant to be read separately. According to Astruc, a later editor had combined the columns into a single narrative, creating the confusions and repetitions noted by Hobbes and Spinoza.
The tools adapted by Astruc for biblical source criticism were developed much further by subsequent scholars, most of them German. From 1780 onwards Johann Gottfried Eichhorn extended Astruc's analysis beyond Genesis to the entire Pentateuch, and by 1823 he had concluded that Moses had had no part in writing any of it. In 1805 Wilhelm de Wette concluded that Deuteronomy represented a third independent source. About 1822 Friedrich Bleek identified Joshua as a continuation of the Pentateuch via Deuteronomy, while others identified signs of the Deuteronomist in Judges, Samuel, and Kings. In 1853 Hermann Hupfeld suggested that the Elohist was really two sources and should be split, thus isolating the Priestly source; Hupfeld also emphasized the importance of the Redactor, or final editor, in producing the Torah from the four sources. Not all the Pentateuch was traced to these four sources: numerous smaller sections were identified, such as the Holiness Code contained in Leviticus 17 to 26.
Scholars also attempted to identify the sequence and dates of the four sources, and to propose who might have produced them, and why. De Wette had concluded in 1805 that none of the Pentateuch was composed before the time of David; since Spinoza, D was connected with the priests of the Temple in Jerusalem during the reign of Josiah in 621 BC; beyond this, scholars argued variously for composition in the order PEJD, or EJDP, or JEDP: the subject was far from settled.
Read more about this topic: Documentary Hypothesis