Posek

Posek (Hebrew פוסק, , pl. Poskim, פוסקים) is the term in Jewish law for "decider"—a legal scholar who decides the Halakha in cases of law where previous authorities are inconclusive.
The decision of a posek is known as a psak din or psak halakha ("ruling of law"; pl. piskei din, piskei halakha) or simply a "psak". In Hebrew, פסק is the root implying to "stop" or "cease"—the posek brings the process of legal debate to finality. Piskei din are generally recorded in the responsa literature. 
==Formulating a ruling (psak din)==
In formulating a ruling, a posek will base the psak din on a careful analysis of the relevant underlying legal principles, as well as a careful study of the application of these principles. A Posek will therefore be thoroughly versed in rabbinic literature and must be a master Talmudist.
The analysis of the legal principles will entail:
#an initial study of the relevant Talmudic Sugyas with commentaries; 
#tracing the development of all related material in the Rishonim (early Middle age rabbinic authorities, such as Maimonides or Rashi) through the Tur and Shulkhan Arukh (the "Code of Jewish Law"); 
#finally, a close analysis of the works of the Acharonim (rabbinic authorities from about the 1500s onwards) discussing the halakha as recorded in the Shulkhan Arukh.
The ruling itself—effectively an application of these principles—will also be consistent with all relevant legal precedents as recorded in the responsa literature, and with all relevant codified law with an emphasis on the Shulkhan Arukh.
==The role of the Posek==
===Orthodox Judaism===
In Orthodox Judaism poskim will not overrule a specific law, unless based on an earlier authority: a posek will generally extend a law to new situations, but will not change the Halakhah; see further under Orthodox Judaism. (Thus for example, some Halakhic rulings related to electricity when it was new, were derived from rulings concerning another form of human-managed energy, "fire", but that view was subsequently modified as the nature of electricity was clarified when used as an electrical circuit.) 
Poskim play an integral role in Haredi Judaism and Orthodox Judaism. Particularly in the Haredi world, each community will regard one of its poskim as its Posek HaDor ("Posek of the present Generation"). For Lithuanian-style Haredi world it is probably Rabbi Yosef Shalom Eliashiv. For the Sephardi Jews it is probably Rabbi Ovadia Yosef. Hasidic Jews rely on their own Rebbes or leading posek recommended by their Rebbes. Modern Orthodox Jews may select a posek on a more individual rather than a communal basis, although customs vary.
===Conservative Judaism===
Conservative Judaism and Masorti Judaism may re-interpret or even change a law through a formal argument. There are some poskim in the Conservative movement, e.g. Rabbis Louis Ginzberg, David Golinkin, Joel Roth, and Elliot Dorff. In addition, the Conservative movement's Rabbinical Assembly maintains a Committee on Jewish Law and Standards, whose decisions are accepted as authoritative within the Conservative movement. The rulings of any one individual rabbi are considered less binding than a consensus ruling.
===Reform and Reconstructionist Judaism===
Poskim are not found in Reform Judaism and Reconstructionist Judaism, as these movements stress individual autonomy for interpretation of biblical and oral law. Nevertheless, since these movements consider Jewish law for various decisions, responsa on halakhah have been written by some Reform Rabbis, including Solomon Freehof and Walter Jacob. Full text collections of Reform responsa are available on the movement's website.
==List of Orthodox poskim and major works==
===Poskim of past years===
*Yehezkel Abramsky (1886–1976)
*Shlomo Zalman Auerbach (1910–1995, Minchat Shlomo)
*Yoseph Chaim of Bagdad (1832–1909, Ben Ish Chai, Rav Pealim)
*Meir Brandsdorfer (Kaneh Bosem) (1934-2009)
*Avraham Danzig (1748–1820, Chayei Adam)
*Yechiel Michel Epstein (1829–1907, Aruch ha-Shulchan)
*Moshe Feinstein (1895–1985, Iggerot Moshe)
*Shlomo Ganzfried (1804–1886, Kitzur Shulchan Aruch)
*Avraham Gombiner (c.1633–c.1683, Magen Avraham)
*Chaim Ozer Grodzinski (1863–1940, Achiezer)
*Yisrael Meir Kagan (1838–1933, Mishnah Berurah, Chafetz Chaim)
*Avraham Yeshayahu Karelitz (1878–1953, Chazon Ish)
*Sabbatai ha-Kohen (1621–1662, Shach)
*Chaim Kreiswirth (1918–2001)
*Yechezkel Landau (1713–1793, Noda bi-Yehudah)
*Shneur Zalman of Liadi (1745–1812, Shulchan Aruch ha-Rav)
*Ephraim Oshry (1914–2003)
*Chanoch Dov Padwa (1908–2000, Cheishev Ho'ephod)
*Menachem Mendel Schneersohn (1789–1866, Tzemach Tzedek)
*David HaLevi Segal (1586–1667, Turei Zahav)
*Yoel Sirkis (1561–1640, Bach)
*Moses Sofer (1762–1839, Chasam Sofer)
*Yaakov Chaim Sofer (1870–1939, Kaf ha-Chaim)
*Yonasan Steif, (1877–1958)
*Yoel Teitelbaum (1887–1979, Vayoel Moshe, Divrei Yoel)
*Vilna Gaon (1720–1797, Gra)
*Eliezer Waldenberg (1917–2006, Tzitz Eliezer)
*Yechiel Yaakov Weinberg (1878–1966, Seridei Eish)
*Yitzchok Yaakov Weiss (1902–1989, Minchas Yitzchak)
===Living Poskim===
*Dovid Cohen
*Simcha Bunim Cohen, prolific author and pulpit rabbi in Lakewood, New Jersey
*Mordechai Eliyahu
*Yosef Shalom Eliashiv (b. 1910)
*Dovid Feinstein, rosh yeshiva at Mesivtha Tifereth Jerusalem
*Fishel Herskowitz
*Menashe Klein, (Menashe Hakoton, Ungvar Rebbe)
*Avigdor Nebenzahl
*Yehoshua Neuwirth (Shemiras Shabbos Kehelichasah)
*Yechezkel Roth
*Moshe Sacks (Matnas Moshe)
*Hershel Schachter, rosh yeshiva at RIETS
*Chaim Pinchas Sheinberg
*Osher Weiss (Minchas Osher)
*Moshe Lando (Rabbi of Bnei Brak)
*Mordechai Willig, rosh yeshiva at RIETS
*Shmuel Wosner (Shevet HaLevi)
*Ovadia Yosef (b. 1920, Yabbia Omer)
*Yitzchak Berkovits, rosh kollel The Jerusalem Kollel
 
For a listing of major works of responsa by author, see the Bar Ilan University Responsa project website .
==See also==
*Halakha
*Talmud
*Oral Torah
*Gemara
*Rabbeinu Tam
*Dayan
*Rishonim
*Acharonim
*Responsa
*History of Responsa
*Jurist
==References==
* N. S. Hecht et al., An Introduction to the History and Sources of Jewish Law, Oxford University Press.
* Louis Jacobs, A Tree of Life: Diversity, Creativity, and Flexibility in Jewish Law, second edition, Littman Library of Jewish Civilization, 1999.
* Mendell Lewittes, Jewish Law: An Introduction, Jason Aronson Inc., 1994.
* Authority and Autonomy in Pesikat HaHalacha, nishmat.net
* An introduction to the system of Jewish Law, aish.com
* Jewish Law Research Guide, University of Miami Law Library
* Jewish Law: Examining Halacha, Jewish Issues and Secular Law (online journal)
* AskMoses.com, Live Answers
-------------------
--------------
Category:Jewish law