<P> This leaves the question of when these works were created . Scholars in the first half of the 20th century came to the conclusion that the Yahwist was produced in the monarchic period, specifically at the court of Solomon, 10th century BC, and the Priestly work in the middle of the 5th century BC (the author was even identified as Ezra), but more recent thinking is that the Yahwist was written either just before or during the Babylonian exile of the 6th century BC, and the Priestly final edition was made late in the Exilic period or soon after . </P> <P> As for why the book was created, a theory which has gained considerable interest, although still controversial is "Persian imperial authorisation". This proposes that the Persians of the Achaemenid Empire, after their conquest of Babylon in 539 BC, agreed to grant Jerusalem a large measure of local autonomy within the empire, but required the local authorities to produce a single law code accepted by the entire community . The two powerful groups making up the community--the priestly families who controlled the Temple and who traced their origin to Moses and the wilderness wanderings, and the major landowning families who made up the "elders" and who traced their own origins to Abraham, who had "given" them the land--were in conflict over many issues, and each had its own "history of origins", but the Persian promise of greatly increased local autonomy for all provided a powerful incentive to cooperate in producing a single text . </P> <P> Genesis is perhaps best seen as an example of a creation myth, a type of literature telling of the first appearance of humans, the stories of ancestors and heroes, and the origins of culture, cities and so forth . The most notable examples are found in the work of Greek historians of the 6th century BC: their intention was to connect notable families of their own day to a distant and heroic past, and in doing so they did not distinguish between myth, legend, and facts . Professor Jean - Louis Ska of the Pontifical Biblical Institute calls the basic rule of the antiquarian historian the "law of conservation": everything old is valuable, nothing is eliminated . Ska also points out the purpose behind such antiquarian histories: antiquity is needed to prove the worth of Israel's traditions to the nations (the neighbours of the Jews in early Persian Palestine), and to reconcile and unite the various factions within Israel itself . </P> <P> In 1978 David Clines published his influential The Theme of the Pentateuch--influential because he was one of the first to take up the question of the theme of the entire five books . Clines' conclusion was that the overall theme is "the partial fulfillment--which implies also the partial nonfulfillment--of the promise to or blessing of the Patriarchs". (By calling the fulfillment "partial" Clines was drawing attention to the fact that at the end of Deuteronomy the people are still outside Canaan). </P>

What type of book is the book of genesis