The _Tanaïm_ may be considered the most original expounders of the science of Judaism, which they fostered at their academies. In the course of centuries their intellectual labor amassed an abundant store of scientific material, together with so vast a number of injunctions, prohibitions, and laws that it became almost impossible to master the subject. The task of scholars now was to arrange the accumulation of material and reduce it to a system. Rabbi after rabbi undertook the task, but only the fourth attempt at codification, that made by Yehuda the Prince, was successful. His compilation, classifying the subject-matter under six heads, subdivided into sixty-three tractates, containing five hundred and twenty-four chapters, was called Mishna, and came to be the authority appealed to on points of law. Having assumed fixity as a code, the Mishna in turn became what the Bible had been for centuries--a text, the basis of all legal development and scientific discussion. So it was used by the epigones, the _Amoraïm_, or Speakers, the expounders of the third period. For generations commenting on the Mishna was the sum-total of literary endeavor. Traditions unheeded before sprang to light. New methods asserted themselves. To the older generation of Halachists succeeded a set of men headed by Akiba ben Joseph, who, ignoring practical issues, evolved laws from the Bible text or from traditions held to be divine. A spiritual, truly religious conception of Judaism was supplanted by legal quibbling and subtle methods of interpretation. Like the sophists of Rome and Alexandria at that time, the most celebrated teachers in the academies of Babylonia and Palestine for centuries gave themselves up to casuistry. This is the history of the development of the Talmud, or more correctly of the two Talmuds, the one, finished in 390 C. E., being the expression of what was taught at the Palestinian academies; the other, more important one, completed in 500 C. E., of what was taught in Babylonia. The Babylonian, the one regarded as authoritative, is about four times as large as the Jerusalem Talmud. Its thirty-six treatises (_Massichtoth_), in our present edition, cover upwards of three thousand folio pages, bound in twelve huge volumes. To speak of a completed Talmud is as incorrect as to speak of a biblical canon. No religious body, no solemn resolution of a synod, ever declared either the Talmud or the Bible a completed whole. Canonizing of any kind is distinctly opposed to the spirit of Judaism. The fact is that the tide of traditional lore has never ceased to flow.