Deuteronomy was probably written during the reign of King Josiah (c. 640-609 B.C.E.). Its probable author was the high priest Hilkiah and/or his scribesWhile this view is rejected by those who hold to biblical infallibility, it is accepted not only by skeptics but also by many mainstream Christians including Catholics. The US Conference of Catholics Bishops, in its introduction to Deuteronomy, states:
The book was probably composed over the course of three centuries, from the eighth century [Josiah's reign] to the exile and beyond. It bears some relation to “the Book of the Law” discovered in the Jerusalem Temple around 622 B.C. during the reign of King Josiah (2 Kgs 22:8–13). It gives evidence of later editing: cf. the references to exile in 4:1–40; 28:63–68; 29:21–28; 30:1–10.
This theory is based on a reading of 2 Kings 22:
Hilki′ah the high priest said to Shaphan the secretary, “I have found the book of the law in the house of the Lord.” And Hilki′ah gave the book to Shaphan, and he read it. And Shaphan the secretary came to the king, and reported to the king, “Your servants have emptied out the money that was found in the house, and have delivered it into the hand of the workmen who have the oversight of the house of the Lord.” 10 Then Shaphan the secretary told the king, “Hilki′ah the priest has given me a book.” And Shaphan read it before the king.
After Josiah reads the book, he immediately institutes a major religious reform which can only be based on the Book of Deuteronomy, including not only the destruction of non-Israelite religions but also the centralization of Israelite worship in Jerusalem. Even altars dedicated to the God of Israel are destroyed in accordance with Deuteronomy's instruction that worship be allowed only in the "the place which the Lord your will will choose,' namely Jerusalem.
But when you go over the Jordan, and live in the land which the Lord your God gives you to inherit, and when he gives you rest from all your enemies round about, so that you live in safety, then to the place which the Lord your God will choose, to make his name dwell there, thither you shall bring all that I command you: your burnt offerings and your sacrifices, your tithes and the offering that you present, and all your votive offerings which you vow to the Lord. (Deut. 12:10-12)
The idea that Hilkiah's "book of the book in question wasLaw" was Deuteronomy has been discussed since ancient times by the Rabbis. In the Middle Ages, Rabbi Abraham ibn Ezra (c.1093-1167 C.E.), noted the distinctly different meditative style and language of Deuteronomy. He stated that a number of verses must have been written by a later author, possibly Joshua. Similarly, in his introduction to Deuteronomy, Don Isaac Abravanel (1437-1508) suggested that Deuteronomy was written by a different author than the rest Torah.
In the 19th century, with the advent of the documentary hypothesis, the idea that Deuteronomy was written Josiah's time gained wide acceptance among European biblical scholars. It remains an accepted view today, although often criticized by evangelicalEvangelical scholars. An article entitled The Composition of Deuteronomy: When it was Written, published by The Rational Believer, provides both sides of the argument over date and authorship. It concludes:
The mainstream scholarship view is that Deuteronomy is a Josiah-era product, and the evidence seems to concur with that.
Further reading: Richard E. Friedman, Who Wrote the Bible? (San Francisco: Harper, 1997, ISBN 978-0060630355).