She'eloth Ya’avetz [responsa]. Volumes I and II

In these responsa, one finds the controversialist R. Jacob Emden (1697-1776) - largely remembered today for his campaigns against R. Jonathan Eybeschuetz, R. Moses Chaim Luzzatto, and others - in the the more sedate role of supreme halachic authority. Rabbis from throughout Germany, Italy, Poland and Russia would turn to R. Jacob Emden with their questions concerning Jewish Law. Of special interest is Emden's responsum to "Moshe of Dessau," i.e. the Berlin philosopher Moses Mendelssohn (Pt. II, ff. 87v.-88r., responsa nos. 155-156), whom he addresses as "gever chacham be-oz" (an exceedingly wise man). (Mendelssohn had offered a solution to a difficulty raised by Emden in his work Lechem Shamayim, a commentary to the Mishnah. See A. Altmann, Moses Mendelssohn (1973), pp. 209-210, 793.) Ya'avetz is an acronym for Ya'akov ben Tzvi, a reference to the author's famous father R. Tzvi Aschkenazi, known as "Chacham Tzvi." See EJ, Vol. VI, cols. 721-724. Both Raphael and Vinograd give 1759 as the date of publication of Vol II, which is obviously erroneous, for the exchange between Mendelssohn and Emden took place in 1770. See Altmann, p. 793, n. 5