HALACHA, hȧ-lä'kȧ (Heb., rule of procedure, from halak, to go). The general term for the Jewish oral law, which runs parallel with the written law contained in the Bible, and is supposed to be, like this, of divine origin. Its relation to the ordinances contained in the Pentateuch is that of an amplified code to the fundamental religious and civil maxims. The theory being that the oral law was handed down through a long chain of highest authorities (Sinaitic revelation, Moses, Joshua, elders, Great Synagogue [Ezra], etc.), it could only be treated and further developed by the foremost men of each generation, who through their eminence in learning belonged to a kind of aristocracy of mind (hakamim, wise men), towering above the multitude (hediotim, laymen). Their decision on all ordinances involved in contradictory traditions was final, because it was believed to spring from a deeper apprehension of Scripture. An elaborate system of interpretation of the biblical texts was devised, which, frequently sacrificing the spirit to the letter, attached great weight to certain special letters, words, and even signs in the Old Testament, which, seemingly superfluous where they stood, were supposed to point to the injunction under discussion. Halacha embraces the whole field of juridico-political, religious, and practical life, down to its most minute and insignificant details. Originally, as already said, the oral law par excellence, it began to be written down when, as was natural, various opinions and traditions arose as to the correct practice and the danger of sectarianism was imminent. The first collection of laws was instituted by Hillel, Akiba, and Simon ben Gamaliel; but the final redaction of the general code, the Mishna (q.v.), is due to Jedudah Hanassi, about A.D. 220. Later additions to this code are the Baraithas and Tosephtas. Of an earlier date with respect to their contents, but committed to writing in later times, are the three Haggadic books (Midrashim): Siphra or Torath Kohanim (a Haggadic amplification of Leviticus), Siphre (of Numbers and Deuteronomy), and Mechiltha (of a portion of Exodus). The rabbis of the Mishnaic period are called the Tanaim. These were followed by the Arnoraim, who, by discussing and further amplifying the Mishna, became the authors of the Gemara (q.v.). The Halacha was further developed in subsequent centuries by the Saboraim, Geonim, and the authorities of each generation. See Haggada; Midrash; Talmud.