J.J. and Dr. Shaye Cohen go deep into the world of the mishnah and try to mark the boundaries between the world of the mishnah and the world of history. Shaye J. D. Cohen is the Littauer Professor of Hebrew Literature and Philosophy in the Department of Near Eastern Languages and Civilizations of Harvard University, one of the oldest and most distinguished professorships of Jewish studies in the United States. Before arriving at Harvard in July 2001, Prof. Cohen was for ten years the Samuel Ungerleider Professor of Judaic Studies and Professor of Religious Studies at Brown University. Prof. Cohen began his career at the Jewish Theological Seminary where he was ordained and was for many years the Dean of the Graduate School and Shenkman Professor of Jewish History. He received his Ph.D. in Ancient History, with distinction, from Columbia University in 1975. The focus of Prof. Cohen's research is the boundary between Jews and gentiles and between Judaism and its surrounding cultures. What makes a Jew a Jew, and what makes a non-Jew a non-Jew? Can a non-Jew become a Jew, and can a Jew become a non-Jew? How does the Jewish boundary between Jew and non-Jew compare with the Jewish boundary between male Jew and female Jew? On these and other subjects Prof. Cohen has written or edited ten books and over sixty articles. His study of circumcision and gender in Judaism is entitled Why aren't Jewish Women Circumcised? (2005). He is perhaps best known for From the Maccabees to the Mishnah (1987; second edition 2006), which is widely used as a textbook in colleges and adult education, and his The Beginnings of Jewishness (1999), which has been widely discussed in scholarly circles. He has also appeared on educational television, including From Jesus to Christ and Nova on PBS, Mysteries of the Bible on A&E, and various programs on the History Channel. Prof. Cohen has received an honorary doctorate from the Jewish Theological Seminary and appointments as Croghan Distinguished Visiting Professor of Religion (Williams College), the Louis Jacobs Lecturer (Oxford University), the David M. Lewis Lecturer (Oxford University), Lady Davis Visiting Professor of Jewish History (Hebrew University of Jerusalem), the Block Lecturer (Indiana University), the Roland Visiting Lecturer (Stanford University) and the Pritchett Lecturer (University of California, Berkeley). Prof. Cohen lives in Newton, Massachusetts, with his wife Miriam May and children Ava, Jonathan, Ezra, and Hannah.