RABBINICAL LITERATURE, a modern scientific term used to describe the literature of halakhah which is based upon the Oral Law, its traditions and methodology in its different periods, its changing languages, and its varied forms. This definition excludes from its purview such sacred literature as liturgy, piyyutim, and other liturgical compositions, pure Kabbalah works, philosophical bible exegesis, theology, and grammar. On the other hand it frequently includes what appear at first sight to be purely secular topics, such as the works on astronomy–inasmuch as their aim is to clarify topics connected with the calendar, such as laws of the determination of the New Moon and its intercalation; "chronologies of the tannaim and amoraim", which are strictly chronographies, but whose main purpose is to determine according to which authority the halakhah is to be established; homiletic ethical and aggadic works, which aim at giving the practical halakhah and guidance for everyday living, and other similar works. Despite this, or perhaps because of this, the term also includes books on the laws of the Temple and its appurtenances, the laws of ritual cleanness and uncleanness, which will be actual only in the messianic future, since their purpose was regarded as "practical" in view of the ever-present faith in the imminent redemption. Combined with this was the concept of "interpret and receive reward," i.e., the study of Torah for its own sake without regard to its application to practical life, as an independent discipline which was part of the concept of talmud torah, and therefore this literature too is included in the term "rabbinical literature." It must be clearly emphasized that, despite the formal name, the term does not indicate books written by rabbis but works whose subject matter and aim belong to the sphere that concerns rabbis in their function as teachers of Judaism. Works on grammar may have an important halakhic bearing, for instance in connection with the laws of reading the Torah, but in most cases such was not the intention of their authors, whose purpose was primarily to teach grammar for its own sake or as an aid to biblical exegesis. These books are therefore not included in the term "rabbinical literature." The name rabbinical literature is also used in an entirely different sense since it also describes literature written by Rabbanites against the *Karaites in all eras–even if it deals with theology or other non-halakhic topics.
Rabbinical literature can be divided, according to its contents, into several basic categories: exposition of the *Talmud; *responsa; codes and their commentaries; *minhagim; halakhic monographs; rules of conduct and ethical wills, and the like. This formal division, however, was adopted in practice long after the inception of this literature. The term is commonly accepted to indicate every category of this literature as defined above, from Saadiah *Gaon, who was the first rabbinical scholar to write "books" in the present sense of the word. According to this usage rabbinical literature constitutes a stage following the period of talmudic and midrashic literature, which, as is usually accepted, came to a close at the end of the geonic period. No books in the present sense of the word were written, however, from the close of this period until Saadiah, with the possible sole exception of the She'iltot of Aḥa of *Shabḥa. Saadiah was also a very prolific writer, and the many fragments extant of his various works bear evidence to his creativity in every branch of rabbinical literature.
The formal division begins to emerge in the 11th and 12th centuries, and, with the general development of literary expression, it became progressively more refined and defined. In its historical development rabbinical literature may be divided into three periods:
(1) The geonic period;
(2) The period of the rishonim;
(3) The period of the aḥaronim (the subdivisions of each period are dealt with under their separate headings). In its fate and its preservation in manuscripts in libraries or in the genizah, there is not much difference between rabbinical literature and other branches of Jewish literary creativity. It is likewise very difficult to indicate lines of development which are unique or specially characteristic of it. Research into rabbinical literature, as a branch of the study of Jewish literature in general, is still in its infancy, and the basic groundwork toward it has not yet been done. There are as yet no reliable and comprehensive catalogs of Hebrew manuscripts in the different libraries and erroneous identification of books belonging to it is still widespread.