Codex of Jewish Law (halachah) compiled by Judah the Prince circa 220 C.E. (Mishnah is Hebrew for “learning.”) The laws of the Mishnah are arranged conceptually, unlike the appearance of the laws throughout the Torah. Mishnah is “unjustified” law in that it does not bring biblical verses to justify the laws. The Mishnah preserves minority opinions and dissenting opinions and includes a few stories to illustrate the points of law. Avot, a non-legal (aggadah) tractate was appended to the Mishnah. The introduction presents the Oral Torah as authoritative because it derives from the same source as the Written Torah.
[Courtesy : Professor Shai Cherry]