 Yeshayahu Leibowitz (1903–1994) was one of the most outspoken and controversial twentieth century Jewish thinkers and Israeli public intellectuals. Once termed “the conscience of  Israel”[1]  by his childhood contemporary from Riga, Sir Isaiah Berlin, Leibowitz’s thought is founded on a far-reaching theocentrism that allows him to combine a commitment to Orthodox Jewish practice with a stripped-down definition of Jewish faith that yields a radically naturalistic theology – if, indeed, what is left can bear the burden of the term “theology” at all. But the influence of this theocentric commitment spreads far beyond the confines of his views on religious faith. It is the ultimate source of his unyielding criticism of the rabbinic establishment in Israel, and what – “in the face of so much pressure to be sensible, to be realistic, not to let the side down” as Berlin (1983, 18) put it – was seen at the time as a highly controversial stance regarding Israeli policy towards the territories occupied since the Six Day war.