In 1952, Waldemar Gurian, founding editor of The Review of Politics, commissioned Eric Voegelin, then a professor of political science at Louisiana State University, to review Hannah Arendt's recently published The Origins of Totalitarianism (1951). She was given the right to reply; Voegelin would furnish a concluding note. Preceding this dialogue, Voegelin wrote a letter to Arendt anticipating aspects of his review; she responded in kind. Arendt's letter to Voegelin on totalitarianism, written in German, has never appeared in print before. She wrote two drafts of it, the first and longest being the more interesting. It contained an early reference to her thinking about the relationship among plurality, politics, and philosophy. It also invoked her notion of the compelling "logic" of totalitarian ideology. But this was not the letter Voegelin received. Because of this, he misunderstood significant parts of her argument. Below, the two versions of Arendt's letter are translated. They are prefaced by a translation of Voegelin's initial message to Arendt. An introduction compares Arendt's letters, offers context, and provides a snapshot of Arendt's and Voegelin's perceptions of each other. Their views of political religion and human nature are also highlighted. Keyed to Arendt and Voegelin's letters are pertinent aspects of the debate in The Review of Politics that followed their epistolary exchange.