AḤARONIM (Heb. אַחֲרוֹנִים; lit. "the later" [authorities]), a term used to designate the later rabbinic authorities, in contrast to the *rishonim, the earlier authorities. Although scholars differ as to the exact chronological dividing line between the two, some antedating it to as early as the period of the *tosafists (12–13th century) and others to the appearance of the Sha'arei Dura of Isaac ben Meir *Dueren (beginning of 14th century), the general consensus of opinion is that the period of the rishonim ends with the death ofIsrael *Isserlein (1460) and that of the aḥaronim begins with the appearance of the *Shulḥan Arukh of Joseph *Caro with the additions of Moses *Isserles (1525–1572). Caro in his monumental work Beit Yosef, of which the Shulḥan Arukh is a codified digest, had taken into consideration the works of all his predecessors, but had tended to ignore the decisions of the Ashkenazi posekim of Germany and Poland since the appearance of the Arba'ah Turim of *Jacob b. Asher, and this omission was filled by Isserles. It is therefore a fitting point at which to commence the later period.
As a result of the introduction of the method of *pilpul by R. Jacob *Pollack (d. 1530) and the increasing study of Torah in Poland, the desire to discover new interpretations and to raise problems in the Talmud and resolve them by means of pilpul became particularly vigorous in that country, and the second half of the 16th century saw the appearance of some of the greatest aḥaronim and commentators of the Talmud and gave a powerful impetus to the study of Torah in Poland.
R. Solomon b. Jehiel *Luria (the Maharshal; 1510–1573) opposed the Beit Yosef and the Shulḥan Arukh on the same grounds as Isserles. Relying on the Talmud itself as the only source for halakhic ruling he established in each case the halakhah of the Talmud and after comparing the different views of all the posekim decided the halakhah only as it reflected the statement of the Talmud itself. In his Yam shel Shelomo, he took care to determine the correct version of the talmudic text; his Ḥokhmat Shelomo comprises annotations on the Talmud, Rashi, and the tosafot. To the same era belong R. Abraham b. Moses di *Boton (1545–1588), author of the Leḥem Mishneh, and R. Bezalel *Ashkenazi (d. 1592), author of the Shitah Mekubbeẓet, covering most tractates of the Talmud and giving the explanations of the rishonim to the topics of the Talmud. He also compiled responsa. Others are R. Solomon b. Abraham ha-Kohen (the Maharshakh; d. 1602), one of the greatest rabbis of Turkey and author of four volumes of responsa, to the first of which is appended explanations of and novellae to Maimonides' Yad; R. Jacob b. Abraham *Castro (the Maharikas; 1525–1610), author of Erekh Leḥem on the four parts of the Shulḥan Arukh, regarded as the basis for halakhic decision by the rabbis of Ereẓ Israel and Egypt; and R. Elijah b. *Ḥayyim (Maharanaḥ; 1530–1610), author of Teshuvot ha-Ranah.
The opposition to the Shulḥan Arukh was continued by R. Mordecai *Jaffe (1530–1612), author of the Levushim (issued 1590–1599), which summarizes the halakhah, explaining the reasons, sources, and grounds for deciding between the divergent views of different posekim, but taking a stand against the prolixity of the Beit Yosef on the one hand and the exceptional brevity of the Shulḥan Arukh on the other. He, too, relies in the main upon the views of the Ashkenazi and Polish scholars, and in this respect also opposes Caro's tendency to decide in favor of the view of the Sephardim; R. Joseph b. Moses *Trani (Maharit; 1568–1639), who compiled commentaries to most tractates of the Talmud, to Maimonides' Yad, and to the Turim; also R. Joshua *Falk b. Alexander ha-Kohen (the Sema; d. 1614), author of the Derishah u-Perishah and the Sefer Me'irat Einayim(Sema), endeavored to explain the Tur and the Shulḥan Arukh at length and to supplement those laws whose sources and reasons are not given in the Shulḥan Arukh, attempting at the same time to compromise between Caro and Isserles. The method of R. Meir b. Gedaliah *Lublin (Maharam of Lublin; 1558–1616) was to penetrate deeply into the meaning of the Talmud and the tosafot, the final decision being based on examination of the talmudic sources and the early posekim, which caused him to oppose basing halakhic decisions upon the Shulḥan Arukh. His best-known book, Me'ir Einei Ḥakhamim, consists of novellae and interpretations of the Talmud. R. Benjamin Aaron *Slonik (d. 1620), a distinguished pupil of Isserles and the colleague of the "Sema," the "Levush," and Meir of Lublin, compiled the responsa Masat Binyamin (1633) and was regarded in his generation as an outstanding posek. Another contemporary of the Maharam, Samuel Eliezer b. Judah *Edels (the Maharsha; 1555–1631), penetrated deeply into the plain meaning of the Talmud and the tosafot. His opposition to the Shulḥan Arukh is not so obvious, since he does not deal with halakhic rulings. Despite this he complains about those "who give halakhic rulings from the Shulḥan Arukh without knowing the reason for each matter." He compiled Ḥiddushei Halakhot (2 pts.; 1612–1621) and Ḥiddushei Aggadot (2 pts.; 1627–1631). This latter work makes the Maharsha's commentaries different from most others. Maharsha endeavors to understand the often cryptic aggadot through allegorical and symbolic interpretations. The Shenei Luḥot ha-Berit of R. Isaiah b. Abraham ha-Levi *Horowitz (the Shelah; 1560–1632) contains laws following the order of the festivals, an enumeration of the 613 commandments (see *Commandments, the 613), and their reasons. Halakhah is only a small portion of the Shenei Luḥot ha-Berit. This encyclopedic work includes philosophy, Kabbalah, biblical and talmudic interpretations as well as ethics (musar) and discussions of talmudic methodology. His son, R. Shabbetai Sheftel (1590–1660), was the author of the Sefer Vavei ha-Ammudim, appended to his father's work. R. Nathan Nata b. Solomon *Spira (1585–1633) published novellae to the Hilkhot ha-Rif entitled Ḥiddushei Anshei Shem (1720). R. Meir b. Jacob ha-Kohen *Schiff (Maharam Schiff; 1608–1644) compiled novellae to the whole Talmud and the Turim, of which only those to five tractates were published under the title Ḥiddushei Halakhot (1741; 1747). R. Joel b. Samuel *Sirkes (the Baḥ; d. 1640) was aware, as was the Sema, that theBeit Yosef could not explain the Tur in a sufficiently satisfactory manner because its main purpose was to arrive at halakhic decisions and, in consequence, in his Bayit Ḥadashwrote "an extensive commentary on the Tur having at the same time the aim of restoring it to its former authority and glory in halakhah in order thereby to diminish" the value of the Shulḥan Arukh. One of the greatest scholars of Salonika, a great posek and one of the greatest responders, was R. *Ḥayyim Shabbetai (Maharḥash; 1557–1647). R. *Joshua Hoeschel b. Joseph of Cracow (d. 1648) endeavored in his Meginnei Shelomo (1715) to defend the views of Rashi against the criticism of the tosafists. A colleague of the Baḥ, R. Eliezer b. Samuel Ḥasid Ashkenazi, who was one of the rabbis of the Council of Four Lands, wrote halakhic pilpulim into his Dammesek Eliezer (1646), which were utilized byḤayyim *Benveniste in his Keneset ha-Gedolah. R. Yom Tov Lipmann *Heller (1579–1654), author of the Tosafot Yom Tov, also opposed the Shulḥan Arukh, his aim being to make the Mishnah the basis for authoritative halakhah, taking into consideration the early and later commentators and posekim. He compiled an extensive commentary in two parts on the Rosh: (1) Ma'adanei Melekh and (2) Leḥem Ḥamudot. R. Moses b. Isaac Judah *Lima (d. 1658) made a summary in his commentary Ḥelkat Meḥokek on the Shulḥan Arukh, Even ha-Ezer, which is based upon a comparison of talmudic sources and the views of the rishonim with the Shulḥan Arukh, while emphasizing the method of pilpul. There are extant from R. *Joshua Hoeschel b. Jacob, known popularly as the "Rebbi Reb Hoeschel" (d. 1663), halakhic novellae to tractate Bava Kamma and novellae on the Sefer Mitzvot Gadol. Two commentators on the Shulḥan Arukh, known from their works as the Taz and the Shakh, through whom the Shulḥan Arukh attained its most developed state and widespread acceptance, were active during the period of the *Chmielnicki pogroms of 1648: R. *David b. Samuel ha-Levi (the Taz; 1586–1667) intended through his commentary Turei Zahav to restore authoritative decision to its proper place, arriving at the definitive halakhah through comparing the different views in order to arrive at a final decision, yet in his eyes the Shulḥan Arukh was the decisive halakhic ruling. In 1978, C. Chavel published a definitive edition of the Taz's novellae on Rashi's commentary on the Pentateuch. R. *Shabetai b. Meir ha-Kohen (Shakh; 1621–1663) in his Siftei Kohen explains the Shulḥan Arukh and decides between its author and Isserles, striving at the same time to harmonize their views. In the Siftei Kohen on the Ḥoshen Mishpat he summarizes the views of all the rishonim and aḥaronim, trenchantly criticizing and negating the existing views and laying down new legal principles. R. Menahem Mendel b. Abraham *Krochmal (1600–1661), a disciple of both the Baḥ and the Taz, is the author of the noted responsa Ẓemaḥ Ẓedek (1675) on the four parts of the Shulḥan Arukh.
In the generation of the Shakh there was in Poland-Lithuania, particularly in Vilna, a concentration of outstanding Torah scholars. R. *Hillel b. Naphtali Ẓevi (1615–1690) compiled the novellae Beit Hillel (1691) on the Shulḥan Arukh, Yoreh De'ah and Even ha-Ezer. R. Moses b. Naphtali Hirsch *Rivkes of Vilna (second half of the 17th century) compiled the Be'er ha-Golah (1662), giving the talmudic sources of the laws of the Shulḥan Arukh, in Maimonides' Yad, and in the works of the rishonim. R. *Ephraim b. Jacob ha-Kohen (1616–1678) wrote the well-known responsa Sha'ar Efrayim. R. Aaron Samuel b. Israel *Koidonover (Maharshak; 1624–1676) wrote the novellae Birkat ha-Ẓevaḥ (1669). R. *Samuel b. Uri Shraga Phoebus (mid 17th cen.) was the author of the commentary Beit Shemu'el (1689) to the Even ha-Ezer. R. Ḥayyim b. Israel Benveniste (1603–1673) in hisKeneset ha-Gedolah gave a digest of the particulars of all new decisions cited in the responsa of outstanding aḥaronim from the time of Joseph Caro to his own time. This work, the first after the Shulḥan Arukh to assemble an anthology of responsa, was accepted in Sephardi and Ashkenazi rabbinical circles as an authoritative work that could be relied upon for practical rulings. Of other responsa anthologies mention must be made of the Panim Ḥadashot (1651) of Isaac b. Abraham Hayyim *Jesurun (d. 1655) and the Leket ha-Kemaḥ of R. Moses *Ḥagiz (1672–1751). R. Aaron *Alfandari (1690?–1774) in his Yad Aharon supplements the Keneset ha-Gedolah from works not in the possession of Benveniste. He also wrote Mirkevet ha-Mishneh, novellae to Maimonides' Yad.
The following authoritative commentaries to the Oraḥ Ḥayyim should be noted: the Olat ha-Tamid (1681) of Samuel b. Joseph of Cracow, and especially the Magen Abraham(1692) of Abraham Abele b. Ḥayyim ha-Levi *Gombiner (1637–1683), who endeavored to arrive at a compromise between Caro's rulings and the amendments of Isserles, and in whose eyes the Shulḥan Arukh was the final authority; Gershon b. Isaac *Ashkenazi (Ulif; d. 1693), compiler of the responsa Avodat ha-Gershuni (1699) and Ḥiddushei ha-Gershuni (1710), notes and novellae to the Shulḥan Arukh, is known for his strictness in laws of marriage; Jair Ḥayyim Bacharach (1638–1701), whose reputation rests on his responsa Havvat Ya'ir (1699) and was opposed to pilpul; Aryeh Leib *Gunzberg (1640–1718), author of the responsa Sha'agat Aryeh, Sha'agat Aryeh ha-Ḥadashot, and novellae to tractates of the Talmud. Among the rabbis of Jerusalem in that generation were: Moses b. Jonathan *Galante (1620–1689), author of Ẓevaḥ ha-Shelamim (1698) andKorban Ḥagigah (1709); Moses b. Solomon ibn *Ḥabib (1654–1696), author of novellae to tractates of the Talmud and of Get Pashut (1719). Peri Ḥadash (1692), a commentary compiled by *Hezekiah b. David Da Silva (1659–1698), added to the Shulḥan Arukh and contains pungent criticism of the posekim, including Caro himself. Abraham b. Saul *Broda (1650–1717) wrote novellae on talmudic tractates entitled Eshel Avraham and Toledot Avraham. Elijah b. Benjamin Wolf *Shapira (1660–1712) was the author of Eliyahu Rabbah, novellae on the Sefer ha-Levush. Ẓevi Hirsch b. Jacob *Ashkenazi (Ḥakham Ẓevi; 1600–1718) published in 1712 his responsa, novellae, and comments. His son, Jacob *Emden (1698–1776), compiled Mor u-Keẓi'ah, comments and novellae to the Oraḥ Ḥayyim. Jacob Emden also wrote an extensive commentary on the prayer book as well as various philosophical works. Samuel b. Joseph Shattin ha-Kohen (Maharshashakh; d. 1719), an outstanding German scholar, published Kos ha-Yeshu'ot (1711), novellae to the tractates of the order Nezikin. Judah *Rosanes (d. 1727), one of the greatest Turkish scholars, achieved fame with his Mishneh la-Melekh (1731), novellae on theYad, and Al Parashat Derakhim (1728). Jacob b. Joseph *Reischer (d. 1733) compiled the commentaries Minḥat Ya'akov, Shevut Ya'akov, and Ḥok le-Ya'akov on the Shulḥan Arukh. Most of the halakhic works, novellae, and responsa of David *Oppenheim (1664–1736), famed for his large library, remain in manuscript. Alexander Sender b. Ephraim Zalman *Schor (d. 1737) was the author of Simlah Ḥadashah (1733), rulings in the laws of sheḥitah and terefot together with a pilpulistic commentary Tevu'ot Shor that became an authoritative source on matters pertaining to sheḥitah. Elazar Rokeaḥ of Brody (d. 1741) compiled Arba Turei Even (1789), novellae to the Yad and the Tur. A contemporary of the Peri Ḥadash, Hayyim b. Moses *Attar (1696–1743), author of the Or ha-Ḥayyim on the Pentateuch, wrote Peri To'ar, a commentary on the Yoreh De'ah, in which he defends the Tur, Beit Yosef, and all rishonim from the criticisms of the Peri Ḥadash.
Among outstanding aḥaronim in the 18th century are Meir b. Isaac *Eisenstadt (Maharam Esh; 1670–1744), author of Panim Me'irot (3 pts.; 1710–1738); and Isaac Hezekiah b. Samuel *Lampronti (1679–1756), author of the halakhic encyclopaedia Paḥad Yiẓḥak. The Yad Malakhi (1767) of his contemporary *Malachi b. Jacob ha-Kohen is a methodology of the Talmud and posekim in three parts. Jacob Joshua b. Ẓevi Hirsch *Falk (1680–1756) achieved fame with his extensive talmudic work Penei Yehoshuah (4 pts.). Nethanel b. Naphtali Ẓevi *Weil (1687–1769) was the author of Korban Netanel (1755), a commentary of the Rosh of Asher b. Jehiel to the orders Mo'ed and Nashim, and of Netiv Ḥayyim, notes to the Oraḥ Ḥayyim. Aryeh Loeb b. Saul *Loewenstamm (1690–1755) of Amsterdam republished the responsa of Moses Isserles (1711), adding to it Kunteres Aḥaron, parallels from the responsa of the Maharshal. Jonathan *Eybeschuetz (1690–1764) wrote the pilpulistic and acute commentaries Kereti u-Peleti (1763) to theYoreh De'ah and Urim ve-Tummin (1775) to the Ḥoshen Mishpat. Ẓedakah b.Saadiah *Ḥoẓin of Baghdad (1699–1773) published novellae to all four parts of the Shulḥan Arukh. Among the works of Judah b. Isaac *Ayash (1700–1760), an Algerian scholar who settled in Ereẓ Israel during his last years, known also to German and Polish scholars, are Leḥem Yehudah on Maimonides' Yad and the responsa Beit Yehudah. Eliezer b. Samuel De *Avila (1714–1761), a great Moroccan scholar, compiled Magen Gibborim, novellae to talmudic tractates, and Milḥemet Mitzvah (1805) on the sources of halakhot in the Talmud and posekim.
Exceptional prominence was achieved by Ezekiel b. Judah ha-Levi *Landau (1713–1793), the author of the Noda bi-Yehudah, who in his novellae established new halakhic rulings. Solomon b. Moses *Chelm (1717–1781) became known through his Mirkevet ha-Mishneh in which he defends Maimonides from the strictures of *Abraham b. David of Posquieres (the Rabad), at the same time explaining the views of Maimonides and the commentators on the Yad. David Samuel b. Jacob *Pardo (1718–1790) is known through hisShoshannim le-David on the Mishnah and Hasdei David on the Tosefta. Meir *Margoliouth's (d. 1790) responsa Me'ir Netivim reflect the precarious basis of Jewish life in Poland and Lithuania.
Samuel b. Nathan ha-Levi of Kalin's (1720–1806) Maḥaẓit ha-Shekel (1807) is a commentary on the Magen Avraham to the Oraḥ Ḥayyim and on the Shakh to Yoreh De'ah Hilkhot Meliḥah. One of the most prominent personalities among aḥaronim in the 18th century is *Elijah b. Solomon Zalman, the Gaon of Vilna (ha-Gera; 1720–1797). In his commentary on the Shulḥan Arukh he stresses the connection between its decisions and the primary sources in the two Talmuds; when explaining the talmudic view the Gaon indicates his sources at the same time as he examines the different versions and determines the talmudic text. Noted for its terse style, the Gaon's commentary on the Shulḥan Arukh reflects his outstanding scholarship and genius. Ḥayyim Joseph David *Azulai (the Ḥida; 1724–1806) wrote halakhic laws and responsa, as well as the Shem ha-Gedolim, a comprehensive compilation of Jewish authors and their works up to that time. In 1771, about a century after the publication of the Shakh and the Taz, Joseph *Teomim (1727–1792) published his commentary Peri Megadim, whose main purpose was to comment on them, adding new laws he had collected and laying down halakhic principles. Another well-known commentary is the Levushei Serad to Oraḥ Ḥayyim and Yoreh De'ah of David Solomon Eibeschutz of Soroki (Safed, 1809). Pinḥas ha-Levi *Horowitz of Frankfurt on Main (1730–1805) became known from his Sefer Hafla'ah and Sefer ha-Makneh. In his well-known commentary Keẓot ha-Ḥoshen on Ḥoshen ha-Mishpat, Aryeh Leib b. Joseph ha-Kohen *Heller (1745–1813) used the method of pilpul, at the same time stressing the need for rational understanding. Particular note should be taken of *Shneur Zalman of Lyady (1747–1812), the founder of Ḥabad Ḥasidism and author of the Tanya, who prepared for his ḥasidic followers a new Shulḥan Arukh which was issued in five parts in 1864. Abraham b. Samuel *Alkalai (1749–1811) wrote Zekhor le-Avraham on the Turim, which was relied on by halakhic authorities in Ereẓ Israel. Ḥayyim b. Isaac *Volozhiner (1749–1821), the distinguished disciple of the Gaon of Vilna and founder of the Volozhin Yeshivah, continued the latter's method of shunning pilpul and stressing the literal and straightforward meaning in halakhah. The vast majority of his writings were destroyed by fire at the end of his life, leaving us with only a small number of responsa and his philosophical work, Nefesh ha-Ḥayyim. Meshullam *Igra (1752–1802), an outstanding Galician and Hungarian scholar, compiled Igra Ramah on the orders of Mo'ed andNashim, and responsa. Mordecai b. Abraham *Banet (1753–1829) wrote Be'ur Mordekhai, novellae on the Sefer ha-Mitzvot of the Mordekhai, as well as other novellae.Jacob *Lorbeerbaum of Lissa (1760–1832), in his commentary Netivot ha-Mishpat on the Ḥoshen ha-Mishpat, summarized the sources of the halakhah, while his Ḥavvat Da'at to the Yoreh De'ah is of decisive importance for halakhic ruling. The following Yemenite rabbis living in the second half of the 18th century should be noted: Yaḥya b. Joseph *Saliḥ, av bet din in San'a and author of the responsa Pe'ullat Ẓaddik dealing with the practical problem of Yemenite Jews; David b. Shalom *Mizraḥi (1696–1771) and his son Yiḥya (1734–1809) in San'a wrote the responsa Revid ha-Zahav (1955) on Oraḥ Ḥayyim and Yoreh De'ah on the customs of Yemenite Jews.
Of the most notable 19th century scholars, the following deserve mention: Joshua Heschel b. Isaac *Babad (1754–1838), author of the responsa Sefer Yehoshua (1829); Baruch b. Joshua Ezekiel Feiwel *Fraenkel-Teomim (1760–1828), known from his Barukh Ta'am; one of the greatest aḥaronim in this period was Akiva b. Moses *Eger (1761–1837), famous for his novellae, his Gilyon ha-Shas, and responsa; Moses b. Samuel *Sofer (Ḥatam Sofer; 1762–1839), known by his responsa, novellae on the Talmud, and Pentateuch commentary; Abraham Samuel Benjamin *Sofer, author of Ketav Sofer, son of the Ḥatam Sofer, and his son Simḥah Bunem, author of Shevet Sofer; *Israel b. Samuel Ashkenaziof Shklov (d. 1839), author of Pe'at ha-Shulḥan on laws connected with Ereẓ Israel that were not dealt with by Caro in his Shulḥan Arukh; Ephraim Zalman *Margolioth (1760–1828), author of Beit Efrayim on all four parts of the Shulḥan Arukh, Sha'arei Teshuvah, and Pitḥei Teshuvah; Abraham b. Gedaliah *Tiktin (1764–1821), author of Petaḥ ha-Bayit on the Talmud and Shulḥan Arukh; Jacob Meshullam *Ornstein (1775–1839), author of Yeshu'ot Ya'akov; Israel b. Gedaliah *Lipschutz (1782–1861), famous for hisTiferet Yisrael commentary on the Mishnah; Solomon b. Judah Aaron *Kluger (Maharshak; 1783–1869) wrote novellae on the Shulḥan Arukh and compiled works on halakhahand aggadah; Menahem Mendel Schneersohn of Lubavitch (1789–1866), author of the responsa Ẓemaḥ Ẓedek; Ḥayyim b. Leibush *Halberstam, the ḥasidic rabbi of Zanz (1793–1876), author of the responsa Divrei Ḥayyim, characterized by its blending of scholarship and Ḥasidism; Judah b. Israel *Aszod (1794–1866), outstanding Hungarian rabbi, became widely known through his She'elot u-Teshuvot Maharia and Ḥiddushei Maharia; Jacob b. Aaron *Ettlinger (1798–1871), known from responsa Binyan Ẓiyyon(1868), his Arukh la-Ner, novellae to tractates of the Talmud, and his Bikkurei Ya'akov; Isaac Meir Alter of Gur (1799–1866), known for his Ḥiddushei ha-Rim and She'elot u-Teshuvot ha-Rim; Samuel b. Joseph *Strashun (1794–1872) wrote haggahot (notes) to the Talmud; Joseph *Babad (1800–1875) became famous through his Minḥat Ḥinnukh(1869), extensively used especially among yeshivah students, its main aim being not to determine the halakhah but to stimulate further study by raising new problems. The Minḥat Ḥinnukh is an extensive commentary of the medieval work, Sefer ha-Ḥinnukh. Mention must be made of the abridgments of the Shulḥan Arukh by Abraham *Danzig (1748–1820) in his Ḥayyei Adam and Ḥokhmat Adam and by Solomon *Ganzfried (1804–1886) in his Kitzur Shulḥan Arukh; Zevi Hirsch b. Meir *Chajes (1805–1855) wrote theDarkhei Hora'ah and Mevo ha-Talmud (1845) on talmudic methodology, the responsa Maharaz (1849), and notes and novellae on most tractates of the Talmud; Moses b. Joseph *Schick (Maharam Schick; 1807–1879), a Hungarian posek, author of about 1,000 responsa; Joseph Saul *Nathanson of Lemberg (1810–1875), the posek of his generation, who opposed pilpul; David Dov *Meisels (1814–1876), known from his responsa Ha-Radad on Oraḥ Ḥayyim and Even ha-Ezer (1903); Naphtali Ẓevi Judah *Berlin (the Neẓiv; 1817–1893) of Volozhin, author of Ha'amek Davar on the Pentateuch and Ha'amek She'elah on the She'iltot of R. Aḥai; Moses Joshua Judah Leib *Diskin(Maharil Diskin; 1817–1898), the rabbi of Brest-Litovsk, who served as rabbi of Jerusalem from 1877, compiled Torat Ohel Moshe and responsa; Jacob Saul b. Eliezer Jeroham *Elyashar (1817–1906), Sephardi chief rabbi of Ereẓ Israel wrote thousands of responsa in answer to inquiries; Isaac Elhanan b. Israel *Spektor of Kovno (1817–1896), author of the responsa Be'er Yizḥak, Naḥal Yizḥak on the Ḥoshen ha-Mishpat, and the responsa Ein Yizḥak; Joseph Baer *Soloveichik of Volozhin (1820–1892) wrote the novellae Beit ha-Levi and responsa with the same title; Shalom b. Yaḥya *Ḥabshush (1825–1905), dayyan and head of a yeshivah in San'a, published novellae and comments on the laws ofsheḥitah and terefot; Isaac Judah b. Hayyim Samuel *Schmelkes (1828–1906) of Lemberg is known for his responsa Beit Yizḥak in six volumes; Jehiel Michael *Epstein's (1829–1908) Arukh ha-Shulḥan aims at bringing some of the rulings of the Shulḥan Arukh up to date; he also wrote Arukh ha-Shulḥan le-Atid; Shalom Mordecai b. Moses *Shvadron (1835–1911), known as Maharsham, whose genius is reflected in the seven volumes of his responsa; Abraham Bornstein of *Sochaczew (1839–1910), author of the responsa Avnei Nezer on the Shulḥan Arukh; Isaac Jacob *Reines (1839–1915), who in his Ḥotam Tokhnit and Urim Gedolim eschewed pilpul and introduced a purely logical approach to halakhah. Of noted commentators on the Jerusalem Talmud in the 18th–19th centuries, mention must be made of *Elijah b. Loeb of Fulda (Raf; d. 1725); David b. Naphtali Hirsch *Fraenkel (1707–1762), author of the Korban ha-Edah; Moses b. Simeon *Margoliot (1710–1781), author of the commentary Penei Moshe; Jacob David b. Ze'ev *Willowski (Ridbaz; 1845–1913), who settled in Safed in his last years and whose commentary on the Jerusalem Talmud and his responsa are regarded as classics.
Among Oriental aḥaronim the following are worthy of note: Hayyim *Palache (1788–1869) of Smyrna, author of 26 books, including the responsa Lev Ḥayyim and comments on the Shulḥan Arukh; *Joseph Ḥayyim b. Elijah Al-Ḥakam (1833–1909) of Baghdad, a great posek known from his Ben Yehoyaddah and Ben Ish Ḥai, which embrace halakhah, aggadah, and homiletics.
Until 1933 the study of Torah was centered in the great and famous yeshivot of Eastern Europe – Poland, Lithuania, Hungary, and Czechoslovakia. During that period centers of Torah also began to be established in the United States. From 1933 on, and following World War II, as a consequence of the liquidation of these centers, the center of spiritual life passed to the United States and Israel, and some scholars immigrated to these new centers during the latter part of their lives: *Meir Simḥah ha-Kohen of Dvinsk (1843–1926), author of the Or Same'aḥ on Maimonides' Yad and Meshekh Ḥokhmah on the Pentateuch; Zevi Hirsch *Shapira of Munkacz (1850–1913), author of Darkhei Teshuvah on the Shulḥan Arukh, and his son Ḥayyim Eleazar (1872–1937), author of the responsa Minhat Elazar; Elijah b. Naphtali Herz *Klatzkin (1852–1932); Hayyim b. Joseph Dov*Soloveichik (Ḥayyim Brisker; 1853–1918), who wrote novellae on tractates of the Talmud and the Yad and devised a new system of talmudic dialectics, and his son Isaac Ze'ev (1886–1960); Joseph *Rozin ("the Rogachover"; 1858–1936), known from his responsa Zafenat Pa'ne'aḥ and commentary on the Pentateuch with the same title; *Israel Meir ha-Kohen (Ḥafez Ḥayyim; 1853–1933), author of the Ḥafez Ḥayyim, dealing with the laws of slander and gossip, and Mishnah Berurah on the first section of the Shulḥan Arukh. TheMishnah Berurah rapidly became the most widely accepted work of halakhah among Ashkenazi Jewry since the publication of the Shulḥan Arukh. Moses Samuel *Glasner(1856–1924), who compiled Dor Revi'i and Shevivei Esh on the Pentateuch; Joseph b. Judah *Engel (1859–1920), whose works on halakhah, aggadah, and Kabbalah are arranged in an encyclopedic manner, in most cases alphabetically; Judah Leib *Zirelson (1860–1941) of Kishinev, author of the responsa Aẓei Levanon, Gevul Yehudah, Lev Yehudah; Ḥayyim Ozer *Grodzinski (1863–1940), author of the responsa Avi'ezer (3 pts.); Abraham Isaac ha-Kohen *Kook (1865–1935), author of the novellae and responsaMishpat Kohen and Iggerot ha-Re'ayah; the Galician rabbi Menahem Munish b. Joshua Heschel *Babad (1865–1938), author of the responsa Ḥavaẓẓelet ha-Sharon; Zalman b. Ben-Zion *Sorotzkin (1881–1966), author of the responsa Moznayim le-Mishpat and Oznayim la-Torah on the Pentateuch; Ben Zion Meir Ḥai *Ouziel (1880–1953), Sephardi chief rabbi (rishon le-Zion) and author of the responsa Mishpetei Ouziel, Sha'arei Ouziel, Mikhmannei Ouziel; Isaac ha-Levi b. Joel *Herzog (1888–1959), Ashkenazi chief rabbi of Israel, wrote Divrei Yiẓḥak (1921), Torat ha-Ohel (1948) on Maimonides' Hilkhot Sanhedrin, and the responsa Heikhal Yiẓḥak (1960; 1967) on Even ha-Ezer, in which he also discusses problems arising from the Holocaust and the establishment of the State of Israel; Dov Berish b. Jacob *Wiedenfeld (1881–1965) of Trzebinia, Galicia, author of the responsa Dover Meisharim (2 pts.; 1958); Moshe Avigdor *Amiel (1883–1946), chief rabbi of Tel Aviv, published Darkhei Moshe, Ha-Middot leḤeker ha-Halakhah; Menahem Zemba (1883–1943), outstanding Polish talmudist of the last generation whose works reflect a blending of acumen and erudition combined with logic and profundity, was the author of the responsa Zera Avraham (1920), Oẓar ha-Sifrei (1929), Oẓar ha-Sifra (1960); Jehiel Jacob *Weinberg (1885–1966), author of the responsaSeridei Esh (4 vols.; 1961–1969) on practical problems arising in recent generations; Moses Mordecai *Epstein (1866–1934), author of Levushei Mordekhai, novellae and expositions on topics in tractates Zevaḥim and Menaḥot; Baruch Ber *Leibowitz (1866–1939), author of Birkat Shemu'el on tractates of the Talmud; Isser Zalman *Meltzer (1870–1954), author of Even ha-Ezel in eight parts; Ẓevi Pesaḥ *Frank (1873–1960), chief rabbi of Jerusalem, who followed the methods of Isaac Elhanan Spektor and Samuel Salant; Elḥanan Bunim *Wasserman (1875–1941), who followed a middle path between pilpul and erudition, stressing the decisions of the rishonim; Meshullam *Rath (1875–1963), a member of the Israel chief rabbinate council, author of the responsa Kol Mevasser; Avraham Yeshayahu *Karelitz (Ḥazon Ish; 1879–1954) published 23 volumes entitledḤazon Ish (the first in 1911); his novellae and halakhot embrace the whole Talmud and all four parts of the Shulḥan Arukh. Karelitz had an enormous impact on the halakhah of the latter half of the 20th century, especially in Israel. Reuven *Katz (1880–1963), rabbi of Petaḥ Tikvah, author of the responsa Degel Re'uven and Duda'ei Re'uven; Isser Yehuda *Unterman (1886–1976), who, with the object of consolidating practical halakhah, established a methodological theory of talmudic research, wrote Shevet Yehudah on halakhic problems; Ovadiah Hadayah (1893–1969) wrote Yaskil Avdi in six parts; Moses *Feinstein (d. 1986) of the U.S., author of the responsa Iggerot Moshe and the accepted posek of Orthodox American Jewry during the second half of the 20th century; Isaac *Nissim (d. 1981), chief rabbi of Israel and rishon le-Zion, published his responsa in his Yein ha-Tov; Eliezer Judah b. Jacob Gedaliah Waldenberg (b. 1917), dayyan in Jerusalem, is the author of Ẓiẓ Eli'ezer; Shlomo Goren (d. 1994), chief rabbi of Israel, published, among others, Yerushalmi ha-Meforash (1961), and Torat ha-Mo'adim (1964); Ovadiah *Yosef (b. 1920), Sephardi chief rabbi of Israel, is the author of the volumesYabbi'a Omer published in Jerusalem between 1954 and 1969.
The aḥaronim laid down many rules for halakhah. The fundamental principle is to take care to act in accordance with the decisions of the Shulḥan Arukh. Some have insisted that those giving authoritative rulings from the Shulḥan Arukh must know their sources in the Talmud (Maharsha to Sot. 22a, S.V. ary). On the other hand the author of the Pitḥei Teshuvah holds that after the addition of the well-known commentaries such as the Taz, Shakh, and Magen Avraham it is permitted to rule from the Shulḥan Arukh itself (Yoreh De'ah 242:8). In the view of many aḥaronim the authoritative works are to be regarded as "our teachers" and anyone failing to take them into consideration in deciding thehalakhah is regarded as guilty of "giving a (different) halakhic decision in the presence of his teacher" (Peri Megadim, beginning oh, section 3).
There is a well-known rule that halakhah may not be learned from the aggadah and the Midrashim (Tosefot Yom Tov, Ber. 5:4; Noda bi-Yhudah, 2nd ed., Yoreh De'ah, no. 161), but one may derive from them a custom being practiced by Jews (Noda bi-Yhuda, ibid.). On the other hand, several aḥaronim hold that where the aggadot and Midrashim do not contradict the Talmud but merely add to it they may be relied upon (Mayim Ḥayyim of the Peri Ḥadash, no. 128; Shevut Ya'akov, pt. 2, no. 178).
The novellae of the aḥaronim reflect a tendency to pilpul and to expand the subjects under discussion with the object of arriving at new halakhic rulings. The conclusions arrived at by outstanding aḥaronim are accepted as new halakhic rulings.
The responsa of aḥaronim discuss a variety of different problems occasioned by the times. These topics reflect local and temporal conditions: World War I, the condition of Jews in the world after it, World War II, the Holocaust, the establishment of the State of Israel – all these raised problems which are dealt with by the great aḥaronim with the object of finding solutions in conformity with the halakhah. Indeed, their contribution to our understanding of the Babylonian and Jerusalem Talmuds cannot be underestimated. Throughout the last five centuries the aḥaronim advanced our knowledge and comprehension of Jewish law, while constantly and rigorously applying it to everyday life. The decision process in Jewish law in the 21st century is not complete without careful consultation with all previous sources, including those of the aḥaronim.