This study of the Law became a veritable science, a science that gradually assumed the very widest dimensions. The name given to it is “Midrash”--interpretation, and it included study, meditation, exposition, investigation, inquiry. The men of the “Return from Exile” who devoted themselves to this work took as the foundation of their labours, first the written Law of Moses, then gradually the records of the Prophets and the other writings subsequently included in the Old Testament canon; and to this material was added the oral Law, or such portion of it which had been preserved, including the sacred traditions which had been handed down from the days of Moses and his successors, and treasured up in the schools of the prophets. In this “Midrash”--for we will keep to the well-known term which generally included all this varied and comprehensive study of the Scribes who lived in the period between the Return from the Exile and the Christian era--two distinct currents can be distinguished. The first of these great currents may be termed Prose, the second Poetry. The first (the prose) is called Halachah (rules, customs); the second (the poetry), Haggadah (tradition and legend, including parable, allegory, lessons).[158] The Halachah (rules) for a very long period were never written down, but were transmitted from teacher to teacher in an unbroken succession, orally, with many and various additions. The Haggadah (traditions) in many cases were, however, written down, and so transmitted. Thus from the period of the Return from the Exile a vast bulk of teaching, largely unwritten, traditional, and legendary, all founded on and closely bearing on the Law (Torah), had been collected by the Scribes and their schools stretching over a period of about five centuries. Some thirty years before the Christian era Hillel, the great Rabbinic master of the period, endeavoured to reduce this great mass of teaching, oral and written, rule and tradition, Halachah and Haggadah, to some definite system and order. He did something in this direction, but died before his task was in any real way completed, and for many years nothing further was done in the way of codifying or arrangement. Then came the great upheaval of A.D. 70, when the Holy City was razed to the ground; when it appeared as though the religion of the Jew was destroyed, now that the Temple round which all the cherished memories of the people were grouped had disappeared. Curiously enough, as it appears to men, the contrary was the case: a wonderful resurrection of religious life was the almost immediate outcome of the fall of the City and Temple.