According to the documentary hypothesis, the Pentateuch was composed at different stages in Israel’s history by four different writers or schools, indicated by the letters J (the Yahwist or, in German, Jahwist source), E (the Elohist source), P (the Priestly code) and D (the Deuteronomic source). The Deuteronomic source is also generally credited with the books of Joshua, Judges, Samuel and Kings.