Twersky was buried in Jerusalem in the Mount of Olives Cemetery.

Born in Boston, Twersky attended the Boston Latin School. He earned a bachelor of arts degree magna cum laude, a master of arts degree and a doctorate, from Harvard University. An ordained rabbi, he also earned a master's degree in Hebrew literature from Hebrew College.

During his life, Twersky earned international acclaim as a scholar and spiritual leader. From 1956 to 1965, he served as an instructor, assistant professor and associate professor of Hebrew and of Jewish history at Harvard.

In July 1965, Harvard named Twersky its second Nathan Littauer professor of Hebrew literature and philosophy. While holding that position, Twersky chaired Harvard's department of Near Eastern languages and literature for six years. From 1978 to 1993, he directed the Harvard Center for Jewish Studies.

Maimonides and Jewish thought were Twersky's primary research interests, and he published several books and articles on these topics. One of his books, "An Introduction to the Code of Maimonides (Mishneh Torah)," published by Yale University Press in 1980, earned him two awards: the Jewish Book Council Award for a book on Jewish thought and the Kenneth Smilen Literary Award for the best book in religious thought, given by Present Tense magazine. In addition, the World Congress for Jewish Studies in 1981 devoted a plenary session to an assessment of the book's importance.

Jay Harris, the Harry Austryn Wolfson professor of Jewish studies at Harvard, said Tuesday that Twersky's research on Jewish thought attempted to "redefine Jewish spirituality" to include "all areas of Jewish learning."

Twersky also wrote extensively on rabbinic history. In recent years, he was studying the 16th through the 19th centuries. Had he completed the research, Harris said, it would have "reshaped the way we think about the period."

Twersky's son, Mayer, said his father was often asked: "Are you a rebbe? Are you a professor? Who are you?

"People could not decipher my father's persona. They saw a world-renowned scholar, a pioneering scholar, a highly original scholar…There was no contradiction between his professorial life and his life as a rebbe.

"He engaged the world at large," the son continued. "He was a member of the academic community. At the same time, he stood apart. He could never become fully integrated…No one could fully understand him, but everyone respected him."

Both Mayer Twersky and his brother, Mosheh, characterized their father as a shy, quiet man, modest about his work and the accolades it brought him.

"He did not try to be nice and caring," said Mosheh Twersky. "If he succeeded in doing that, it was because his behavior was rooted in something much, much deeper."

Mayer Twersky added, "If you were in pain, he was in pain. And, perhaps more remarkably, if you experienced a simchah, he experienced a simchah."

Twersky is also survived by his wife, Dr. Atarah Twersky, and his daughter, Tzipporah Rosenblatt.