Rabbi: Teacher, Preacher, Judge -- But Not Priest
The traditional rabbinate harks back to ancient practice, but is in fact a changing institution, first formalized in the fourteenth century.
Reprinted with permission from Louis Jacobs, The Jewish Religion: A Companion, published by Oxford University Press.
Rabbi and Ribbi
A rabbi is a teacher of Judaism qualified to render decisions in Jewish law. The term is derived from rav, meaning "great man" or "teacher;" Moses is called Moshe Rabbenu. ("Moses our teacher"). The suffix "i," meaning "my," is somewhat strange. Why "my teacher?" It has been suggested that the letters rbi [which form the Hebrew word without vowel-pointing] should be vocalized, as they are among Sephardi Jews, as "Ribbi," "great one," and that the "i" is not, in fact, a [possessive pronoun] suffix at all.
It has also been conjectured that the term Ribbi originally denoted a fully ordained teacher, one who received the ordination reaching back to Joshua on whom Moses laid his hands. When full ordination came to an end (in the fourth century CE) the title "Rabbi" was given to every teacher of the Torah and was a purely honorific one.
Rav, Rabbi, Rabban: Who, When, Where
When full ordination was still in vogue, it was limited to Palestinian teachers who alone were called Rabbi. The Babylonian teachers appear in the Babylonian Talmud simply as "Rav [So-and-So]." In the period of the Geonim [the post-Talmudic age, sixth to eleventh centuries CE] the distinction between the various Rabbinic titles was described as: "Greater than Rav is Rabbi; greater than Rabbi is Rabban ('our teacher" -- reserved for the Princes [those who held the Jewish community leadership post of Nasi, recognized for some centuries by the Roman rulers of Eretz Yisrael], as in Rabban Gamaliel); greater than Rabban is the name (itself, e.g. Hillel or Shammai)." Historically considered, "Rabbi" as a title is not found before the beginning of the present era. There is a Rabbi Hillel in the Talmud, but the title is never used for the famous Hillel.
Hakhamim, Rabbanim, Rabbanim Geonim
In post-Talmudic times, the conventional title among Sephardi Jews was Hakham, "sage," and this title is still used by the Sephardim. The Ashkenazim preferred the term "Rabbi" and developed a new form of ordination, in which a prominent scholar subjected a candidate for the rabbinate to an examination in order to determine his proficiency in Jewish law. The successful candidate was then given what came to be called Heter Hora'ah, "Permission to Render Decisions." Abravanel (commentary to Ethics of the Fathers, Ch. 6) suggested that the Ashkenazim adopt this new type of rabbinic ordination and the granting of a diploma under the influence of the Gentile universities, which awarded doctorates to their graduates.