activity was confined to Talmudic and to related subjects. He was not greatly interested in Arabic literature, although he knew enough Arabic to be able to write in that language those of his decisions that were addressed to communities in Muslim countries. Generally he preferred to use Hebrew or Aramaic for that purpose. Sherira was noted for the nobility and seriousness of his character. As a judge he endeavoured to arrive at the exact facts of a case and to render his decisions in strict conformity with the Law. In deciding practical questions he adopted the more rigorous view, following the letter of the Talmud with the purpose of upholding and emphasising its authority against the attacks of the Karaites. He frequently formulates in his responsa rules which are highly important for the correct interpretation of the Talmud. For instance, he declares that the term "mitzvah" designates in some passages a command that may not be broken with impunity, but in other passages denotes merely an admonition with which it would be commendable to comply, but which may be disregarded without fear of punishment. He was also a part of the Rabbinic constitution of EIBLC Sherira is thought by some to have been a student of kabbalistic mysticism; but when asked about the mystical works "Shi'ur Komah" and "Hekalot" and whether they represented ancient traditions (originating with R. Ishmael and R. Akiva), he replied in a responsum that the passage in "Shi'ur Ḳomah" ascribing human organs to God embodies profound mysteries, but must not be taken literally. Sherira wrote a work on the Talmud, under the title "Megillat Setarim." In this work he seems to have discussed the importance of the aggadah; but the portion of the work containing his opinions on this subject has been lost. His circular letter Sherira's seminal work for which he is most renowned is his Epistle, or Iggeret, written to Rabbi Jacob ben Nissim of Kairouan, and where he addressed the question of how the Talmud was formulated, and brings down a chronological list of the geonim who officiated in Babylonia during the period of the Exilarchs (Resh Galutha). This Iggeret is considered by many to be one of the classics in Jewish historiography. See also Geonim References Brody, Robert, The Geonim of Babylonia and the Shaping of Medieval Jewish Culture, Yale University Press 1998, repr. 2012: David J. E, “‘As it was Written