Israel Prize laureate and Hebrew University Professor Aviezer Ravitzky was in serious but stable condition on Tuesday after he was hit by a bus the previous day while crossing the street at a crosswalk in central Jerusalem. Ravitzky, 61, was rushed to Hadassah-University Hospital at Ein Kerem, where he was treated in the intensive care unit for massive head injuries. The afternoon accident took place near the city's central bus station. The driver of the city bus was detained for questioning and later released on NIS 4,000 bail and placed under house arrest for 48 hours, Jerusalem police spokeswoman Sigal Toledo said. His driving license was disqualified for 90 days. A traffic police investigation of the accident is underway. Ravitzky, who is the head of the Jewish Philosophy department at the Hebrew University of Jerusalem, is one of Israel's most respected philosophers and thinkers. In 2001, Ravitzky was awarded Israel's most prestigious award, the Israel Prize, for his research in Jewish thought. A Senior Fellow at the Israel Democracy Institute, Ravitzky is also the author of several books including Messianism, Zionism and Jewish Religious Radicalism, History and Faith: Studies in Jewish Philosophy and, most recently, Religious and Secular Jews in Israel: A post-Zionist. Ravitzky has served as a visiting professor at various universities in the United States, including Harvard University, the University of Pennsylvania, Rice University, Yeshiva University, Brown University and the Jewish Theological Seminary.