BEIT HILLEL AND BEIT SHAMMAI were two early Jewish schools of thought, or "houses" (beit, from Hebrew bayit, means "house of"), named after Hillel and Shammai, leading sages of Jerusalem in the latter half of the first century bce and in the early first century ce. The schools actually represented two distinct approaches to the study of the oral law that were prevalent from the time of Hillel and Shammai until the beginning of the second century. While very few adherents of either school are known by name, it appears that the Shammaites managed to achieve dominance sometime before the destruction of the Temple in 70 ce. According to some scholars, the "Eighteen Matters" that Beit Shammai is said to have decreed despite the objections of Beit Hillel (J.T., Shab. 1.4, 3c, and parallels) refer to measures instituted during the first...