This article investigates the exchanges of letters of 1987 between the historians Martin Broszat and Saul Friedlander through the interpretive framework of dialogue. It is suggested that dialogue does not have a dyadic structure, but involves ever shifting Thirds that function as mediators in dialogue, i.e., God, conscience, reason, or tradition. On one hand, Thirds provide a seemingly stable, external reference point; on the other hand, they open up space for the play of power and desire. Four categories of Thirds are identified and their place and role in the dialogue between Broszat and Friedlander analyzed. The psychoanalytically inspired notions of and working-through are employed in order to interpret the varying degrees of critical control Broszat and Friedlander were able to apply to these interfering Thirds. Finally, I give an overall interpretation of Broszat s and Friedlander's positions in the dialogue, guided by the concepts of acting-out and working-through.