POSEKIM , a Hebrew term for scholars whose intellectual efforts were concentrated on determining the halakhah in practice (for whom the word "decisors" is sometimes used) in contrast to those commentators who applied themselves to study for its own sake, and in order to facilitate the understanding of the subject under discussion and who are called mefarshim (expositors or commentators). This distinction was already recognized by early authorities who stressed, for instance, that halakhah should not be derived from *Rashi's commentary on the Talmud – since Rashi did not introduce into his commentary various ancillary considerations without which no practical decision can be arrived at, except perhaps for those few instances where Rashi explicitly states that the halakhah is in accordance with his exposition.
In the early period, especially in Germany, the term posekim was identical with the teachers and leaders of the generation in every locality. It included the heads of the yeshivot, avot battei din, rabbis and talmudic scholars generally, on condition that their statements were made "by way of pesak," on actual cases which arose. The ruling of the posek was binding only upon those subject to his authority, since he laid down the halakhah in accordance with local tradition and for the people who accepted his authority. A ruling was never successfully imposed upon communities outside the area of the jurisdiction of the posek. The authority of the posek during this period depended on his being a competent talmudic scholar, possessing a comprehensive knowledge in every field on his subject, and on the fact that he continued the tradition of his locality and of his teachers transmitted to him while he studied under them. In the course of time this situation gradually changed, as a result of the dissemination of the codes, which afforded easy access to sources necessary for deciding the halakhah. From the second half of the 16th century with the beginning of the spread of the Shulhan Arukh, the character of the works by the posekim changed fundamentally. Henceforth the outstanding posekim hardly engaged at all in theoretical exposition, and to the extent that they did do so their commentaries were generally forgotten and ignored. The posek during this period won general recognition by virtue of the extensive practical experience he accumulated and by gaining the approbation of contemporary scholars, by devoting the whole of his intellectual and physical energy to this goal, and by virtue of "divine aid," the charisma with which he was endowed. For a survey of the posekim and their development see *Codification of Law.
C. Tchernowitz, Toledot ha-Posekim (1947); Waxman, Literature, 2 (19602), ch. 4; H.Z. Benedikt, in: ks, 25 (1950), 164, 76; I.Z. Kahana, in: Sinai, 34 (1954), 311–24; idem in: Bar-Ilan Sefer ha-Shanah, 1 (1963), 270–81; A. Goldrat, in: Tagim, 1 (1969), 22–31; Friedberg, Eked, 4 (19562), nos. 1212–14, 1222–26; Shunami, Bibl. 181–3.