Shammai [Hebrew:שמאי] was a Jewish Talmudic scholar of the first century B.C. He was the most eminent contemporary and the halakic opponent of Hillel, and is almost invariably mentioned along with him. After Menahem the Essene had resigned the office of vice-president of the Sanhedrin, Shammai was elected to it, Hillel being at the time president. Shammai was undoubtedly an Israeli, and hence took an active part in all the political and religious complications of his native land. Of an irascible temperament and easily excited, he lacked the gentleness and tireless patience which so distinguished Hillel. Once, when a heathen came to him and asked to be converted to Judaism upon conditions which Shammai held to be impossible, he drove the applicant away; whereas Hillel, by his gentle manner, succeeded in converting him.
Nevertheless Shammai was in no wise a misanthrope. He himself appears to have realized the disadvantages of his violent temper; hence he recommended a friendly attitude toward all. His motto was: "Make the study of the Law thy chief occupation; speak little, but accomplish much; and receive every man with a friendly countenance". He was modest even toward his pupils.
In his religious views Shammai was strict in the extreme. He wished to make his son, while still a child, conform to the law regarding fasting on the Day of Atonement; and he was dissuaded from his purpose only through the insistence of his friends (Yoma 77b). Once, when his daughter-in-law gave birth to a boy on the Feast of Tabernacles, he broke through the roof of the chamber in which she lay in order to make a sukkah of it, so that his new-born grandchild might fulfil the religious obligation of the festival (Suk. 28a). Some of his sayings also indicate his strictness in the fulfilment of religious duties.