Jewish theologian and philosopher, noted for his presentation of the prophetic and mystical aspects of Judaism and for his attempt to construct a modern philosophy of religion on the basis of the ancient and medieval Jewish tradition.

After a traditional Jewish education, Heschel went on to higher studies at the University of Berlin and the Hochschule für die Wissenschaft des Judentums. He taught at the latter school, at the noted Jüdisches Lehrhaus at Frankfurt am Main, at the Institute of Jewish Studies in Warsaw after being deported from Nazi Germany (1938), at the Institute for Jewish Learning in London, and at Hebrew Union College in Cincinnati, Ohio, before taking the chair of professor of Jewish ethics and mysticism at Jewish Theological Seminary of America in New York City (1945), a post he held until his death.

Heschel sought to evoke in 20th-century man the inner depth of devotion and spontaneous response that he discerned in traditional Jewish piety. He also emphasized social action as an expression of the ethical concern of the pious man and was at the forefront of protests and demonstrations in the 1960s and '70s intended to secure equal rights for American blacks and to end the U.S. military intervention in Vietnam.

Although he came to the English-speaking world relatively late in life, he soon achieved a vivid and moving English prose style. Among his best-known works are The Earth Is the Lord's (1950); Man Is Not Alone: A Philosophy of Religion (1951); The Sabbath: Its Meaning to Modern Man (1951); Man's Quest for God: Studies in Prayer and Symbolism (1954); God in Search of Man: A Philosophy of Judaism (1956); and The Prophets (1962; originally published in German in 1936).