This essay provides a general introduction to the special number on Jacob L. Talmon . The essay sketches the outlines of Talmon's intellectual biography, beginning with his study of the origins of totalitarian democracy, moving through his analysis of nationalism and political messianism, and ending with his study of the ideological clash of the 20th century. The essay raises the question of whether Talmon should be seen as a thinker wishing to defend existing traditions (i.e. a ''priest''), or as a radical anti-authoritarian skeptic (i.e. a ''jester''). Moreover, being both an anti-nationalist liberal, and a zionist at the same time, Talmon, the essay shows, was aware of the fact his own stance was problematic and at times even paradoxical. The last section of the essay presents the seven essays, which are included in the special issue. r