Rabbi Joseph Dov Soloveithchik (1903–1993), U.S. talmudic scholar and religious philosopher, and scion of a preeminent Lithuanian rabbinical family, was known to his students simply as "the Rav."

Rav Soloveitchik was born in Pruzhan, Poland where his maternal grandfather, Elijah Feinstein, was the rabbi. Rav Soloveitchik spent his early years in Hasloviz, Belorussia, where his father, Moses, served as rabbi. Until his early twenties, Rav Soloveitchik devoted himself almost exclusively to the study of Talmud and halakhah. Under his father's tutelage, he mastered his grandfather's method of talmudic study, with its insistence on incisive analysis, exact classification, critical independence, and emphasis on Maimonides' Mishneh Torah.

In his late teens Rav Soloveitchik received the equivalent of a high school education from private tutors, and at the age of 22 entered the University of Berlin. He majored in philosophy and was attracted to the neo-Kantian school. In 1931 he received his doctorate for his dissertation on Hermann Cohen's epistemology and metaphysics. That same year he married Tonya Lewit (d. 1967), herself the recipient of a doctorate in education from Jena University, who ably assisted him in all his endeavors.

In 1932 the Rav and his wife emigrated to the United States. A few months after his arrival, Rav Soloveitchik became rabbi of the Orthodox Jewish community of Boston, the city which remained his home. He founded the first Jewish day school in New England, the Maimonides School, and also conducted postgraduate talmudic classes for young scholars who gathered around him. With the influx of European yeshivah students during the late 1930s, this advanced talmudic institute was organized on a more formal basis as the Hekhal Rabenu Hayim Halevi and Yeshivath Torath Israel. However, this new school was disbanded in 1941 when Rav Soloveitchik succeeded his father as professor of Talmud at the Rabbi Isaac Elchanan Theological Seminary of Yeshiva University.

For many years he also lectured at the university's Bernard Revel Graduate School, where he served as professor of Jewish philosophy. In these positions Rav Soloveitchik became the spiritual mentor of the majority of the American-trained Orthodox rabbis, and for decades inspired students to follow his teachings.

From 1952 Rav Soloveitchik also exerted a decisive influence on Orthodoxy in his capacity as chairman of the Halakhah Commission of the Rabbinical Council of America. He also identified himself with the Religious Zionists of America (Mizrachi), and has been the organization's honorary president since 1946. Following the death of Chief Rabbi Isaac Herzog in 1959, Rav Soloveitchik declined to be a candidate to succeed him as Ashkenazi chief rabbi of Israel. He represented the American Jewish Community in the Advisory Committee on Humane Methods of Slaughter set up by the secretary of agriculture in 1959. Rav Soloveitchik was also the principal Jewish representative in Yeshiva University's Institute of Mental Health project undertaken in 1960 with Harvard and Loyola universities to study religious attitudes to psychological problems.

Rav Soloveitchik was looked up to in North America as the unchallenged leader of enlightened Orthodoxy and was popularly known simply as "the Rav." His main influence was through his lectures and public discourses.

As a talmudic and halakhic expositor, Rav Soloveitchik had an unusual facility for explaining difficult technical problems. He was also an orator of note in his native Yiddish, as well as in English and Hebrew. The annual halakhic and aggadic discourse which he delivered in Yeshiva University on the anniversary of his father's death attracted thousands of listeners and was regarded as the major annual academic event for United States Orthodox Jewry.

Although he wrote much, Rav Soloveitchik published very little, continuing his family's tradition of reluctance to appear in print due to the demands of perfectionism. His main publication was a lengthy essay, "Ish ha-Halakhah" (Talpioth (1944), 651–735), in which his basic theological position was stated.

Rav Soloveitchik's thought focused on assessing the human situation. Man is viewed as both passive and active, cause and effect, and object and subject. When man lives in accordance with the halakhah, he becomes master of himself and the currents of his life. He controls his thoughts, desires, and actions, and he ceases to be a mere creature of habit. His life becomes sanctified, and God and man are drawn into a community of existence which Rav Soloveitchik termed "a covenantal community." This community brings God and man together in an intimate, person-to-person relationship. It is only through the observance of the halakhah that man attains this goal of "nearness to God."

Rav Soloveitchik stressed that in halakhah nothing is sacred until man designates it so. A Torah scroll is only holy when it has been sanctified by the scribe, and the Temple and all its appurtenances remain profane unless specifically dedicated by humans. Rav Soloveitchik often pointed out that Mount Sinai, which God sanctified by his descent to man, has retained no trace of holiness whereas Mount Moriah, which Abraham consecrated by his ascent to God, became the site of the Temple and remained eternally holy.

Among his other published essays were "The Lonely Man of Faith" (Tradition, 7 no. 2 (1965), 5–67), and Kol Dodi Dofek (in: S. Federbush (ed.), Torah u-Melukhah (1969), 11–44) in which he defined the position of the Religious Zionist Movement confronted with the realities of the reborn State of Israel. Rav Soloveitchik opposed many aspects of the dialogue initiated by the Catholic Church with Jewish leaders as part of the Church's ecumenical movement during the 1960s. He held that there could be no dialogue concerning the uniqueness of each religious community since each is an individual entity which cannot be merged or equated with a community which is committed to a different faith (see his "Confrontation," in Tradition, 6, no. 2 (1964), 5–29). Rav Soloveitchik's position was accepted as official policy by all segments of Orthodox Jewry.

In later years, Rav Soloveitchik seems to have modified his previous refusal to have any of his oral discourses published and Pinchas Peli published two volumes of them, the first, Al ha-Teshuvah ("On Repentance," 1976), and the second, Be-Sod ha-Yahid ("Aloneness and Togetherness," 1977), a collection from his sparse and scattered writings (1977).

An unauthorized version of his halakhic discourses appeared in print in Israel and Rav Soloveitchik took court action to prevent its distribution. In the Spring 1978 edition of Tradition, 17:2, however, there appear five addresses which he delivered on various occasions. "The Lonely Man of Faith" was republished in Studies in Judaism (1975). Other works presenting Soloveitchik's thought are his Reflections of the Rav: Lessons in Jewish Thought (1979) and The Halakhic Mind (1986). These publications, together with further research into his philosophy by, among others, Nathan Rotenstreich, Joseph Dan, Lawrence Kaplan, Ruth Birnbaum, and Pinchas Peli have established Rav Soloveitchik as a religious existentialist of unique quality.