neighbor as thyself"). The name Falk was thus not a family name until the 19th century, when it was adopted by those whose immediate ancestors had "Falk" as a second name. Encyclopedias will therefore have several entries under "Falk", where "Falk", strictly, is not a surname. References to Rabbi Falk are therefore often via "Yehoshua Falk ben Alexander HaCohen" or "Joshua Falk ben Alexander Katz" or "Joshua Falk Katz". Works Beit Yisrael is a twin commentary on the Tur, composed of the Perishah, a straightforward explanation, and the Derishah, deeper discussions on specific problems. The Perishah clarifies the rulings of the Tur, by tracing them to their sources in the Talmud and Rishonim. The Derishah is devoted to extensive analysis and comparison of the various interpretations and decisions proposed by various Talmudic authorities. Rabbi Falk also wrote: Sefer Me'irat Einayim, a commentary to the Choshen Mishpat section of the Shulkhan Arukh, containing all the decisions of the Rishonim, with an index of their sources. Sefer ha-Hosafah, a supplement to the Darhkei Mosheh of Moses Isserles, printed with the Choshen Mishpat, Dyhernfurth, 1796; Kontres 'al Diney Ribbit, a discourse on the laws relating to the prohibition of usury, followed by some takkanot (ordinances by the Rabbis), Sulzbach, 1692; Novellae on Talmudic treatises. References Its bibliography: Azulai, Shem ha-Gedolim, i.50, 70; Giovanni Bernardo De Rossi, Dizionario, i.116; Solomon Buber, Toledot Anshe Shem, No. 197. External links Beit Israel ("Perishah" and "Derishah"), Prof. Eliezer Segal Joshua Ben Alexander Ha-Kohen, jewishencyclopedia.com History of Jewish family Names, jewishgen.org Meir Wunder, Yehoshu‘a ben Aleksander ha-Kohen, in The YIVO Encyclopedia of Jews in Eastern Europe. 17th-century Polish rabbis 16th-century Polish rabbis Jews from Galicia (Eastern Europe) 1555 births 1614 deaths Kohanim writers of Rabbinic literature Authors of books on Jewish law