For the first time, Hannah Arendt's last book project can be read in its typescript version, accompanied by some previously unpublished supplementary texts. "The Life of the Mind" was Arendt's final book project, which she began working on in the late 1960s, and its typescript was left unfinished when she passed away in 1975. Conceived by her as "a kind of second volume" to the Vita Activa, her famous analysis of the activities of labor, work, and action, "The Life of the Mind" aims to examine the mental activities of thinking, willing, and judging, as well as their relational structure and their respective connection to the world of appearances. This new critical edition presents the text of the typescripts for the first time, as Arendt left them: complete drafts of the first two parts, Thinking and Willing, along with the title page of the third part, Judging. Furthermore, this edition includes a series of supplementary texts, including Arendt's essay "Thinking and Moral Considerations," as well as previously unpublished lecture texts such as "Thinking" and "The History of the Will," along with various seminar notes and course materials. All texts are accompanied by commentary, providing a unique and detailed insight into the wealth of quotes and sources used by Arendt in multiple languages, thus opening up new perspectives on her engagement with the philosophical and literary tradition. This edition will mark a new beginning for the reception of Arendt's great unfinished work.