The Old Testament begins with a comprehensive historical work, reaching from the creation of the world to the fall of the kingdom of Judah (586 B.C.), which in the Hebrew Bible is divided into nine books (Genesis-Kings). The Jews made a greater division at the end of the fifth book (Deuteronomy) and treated the first five books (the Pentateuch) as a unit, with a character and name of its own, the Law. The names of the several books in our Bibles are derived from the Greek version, and indicate in a general way the subject of the book, or, more exactly, the subject with which it begins: Genesis, the creation of the world; Exodus, the escape from Egypt; Leviticus, the priests' book; Numbers, the census of the tribes; Deuteronomy, the second legislation, or the recapitulation of the law.

The three middle books of the Pentateuch (Exodus-Numbers) are more closely connected with one another than with the preceding and following books (Genesis, Deuteronomy); in fact, they form a whole which is only for convenience in handling divided into parts. In these books narrative and legislation are somewhat unequally represented. Exod. 1-19 is almost all narrative, as are also c. 24, and cc. 32-34; the story is picked up again in Num. 10, what lies between is wholly legislative; in Num. 10-27, 28-36, narrative and laws alternate, the latter predominating. It is evident that from the author's point of view the narrative was primarily a historical setting for the Mosaic legislation.

Deuteronomy begins with a brief retrospect (Deut. 1-3) of the movements of the Israelites from the time they left the Mount of God till they arrived in the Plains of Moab, the lifetime of a whole generation. There, as they are about to cross the Jordan to possess the Land of Promise, Moses delivers to them the law which they shall observe in the land, and with many exhortations and warnings urges them to be faithful to their religion with its distinctive worship and morals. Thus Deuteronomy also presents itself essentially as legislation.

The history of the Israelite tribes opens with the account of the oppression in Egypt, the introduction to the story of deliverance. Its antecedents are found in the Book of Genesis, the migration of Jacob and his sons from Palestine to Egypt several generations earlier in a time of famine; and this in turn is but the last chapter in the patriarchal story which begins with the migration of Abraham from Syria or Babylonia to Palestine. Gen. 1-11 tells of creation and first men; the great flood; the dispersion of the peoples, with a genealogical table showing the affinities of the several races and another tracing the descent of Abraham in direct line from Shem the son of Noah. But even in Genesis the interest in the law manifests itself in various ways, such as the sanction of the sabbath, the prohibition of blood, and the introduction of circumcision.

In regarding the whole Pentateuch as Law, or, to express it more accurately, as a revelation of the principles and observances of religion, the Jews were, therefore, doing no violence to the character and spirit of these books; and in ascribing them to Moses they were only extending to the whole the authorship which is asserted in particular of many of the laws, and especially of the impressive exhortations in Deuteronomy which form the climactic close of his work as a legislator.

It was early observed, however, that there are numerous expressions in the Pentateuch which assume the settlement of Israel in Canaan and look back to the age of Moses as to a somewhat remote past: Gen. xxxvi. 31, for example, implies the existence of the Israelite monarchy. In the seventeenth century such anachronisms were bandied about a good deal, but, inasmuch as they were all brief clauses which might well be notes or glosses by scribes, they proved nothing about the age of the main text. The controversy sharpened the eyes of the critics, and many more conclusive facts were brought to light, which proved that the Pentateuch was not the product of one author nor of one age, and that, whatever part Moses may be conceived to have had in it, much must be ascribed to later writers. No methodical attempt had been made, however, to distinguish its different strata, or to discover the sources from which it was compiled. This was first undertaken by an eminent French physician, Jean Astruc, who in 1753 published the results of his investigations under the modest title "Conjectures concerning the Original Memoirs which it appears that Moses used in compiling the Book of Genesis." Astruc's analysis was suggested by peculiar phenomena in the use of the divine names in Genesis, and he was led to the hypothesis that Moses had for the primeval and patriarchal history two principal sources, one of which employed consistently the proper name Jehovah, the other the appellative Elohim (God). The two narratives were in large part parallel, and when they were united in one continuous narrative, repetitions, contradictions, and chronological difficulties were created which disappear when the sources are separated and recombined in their original sequence.

This is not the place for a history of criticism: it must suffice to say that, as the result of the labours of many scholars in the last century and a half upon the problem of the sources and composition of the Pentateuch, historians are now generally agreed that four main sources are to be recognized, of which three run, in varying proportion, from Genesis to Numbers and reappear in Joshua, while the fourth is found in Deuteronomy and Joshua only.