Yeshayahu Leibowitz (1903-1994) was an Israeli philosopher and scientist. For decades, his thinking and persona were the embodiment of a Judaism that was vital, rebuking, involved, and committed to all the Jews of Israel. As seen in this book, Leibowitz's far-reaching public statements are not a certain aspect of this thinking, but its very essence. They are the essence of this thinking even when he is seemingly involved with other, distant issues, such as his exegesis of Maimonides and his writings on popular science. These broad vistas are an invitation to those interested in Israel to meet an Israeli thinker who greatly impressed several generations of listeners, and to become acquainted with part of Israel's intellectual life.