ABSTRACTThose seeking to gain a deeper understanding of the complex interrelationship between Reinhart Koselleck's oeuvre and the turbulences of the Age of Extremes would be well advised to consult Stefan‐Ludwig Hoffmann's Der Riss in der Zeit: Kosellecks ungeschriebene Historik. Hoffmann shows how “Koselleck's personal experience of the abysmal meaninglessness of history” and his “experiences of time in extremis” formed the starting point for his numerous historiographical endeavors and, ultimately, for his unwritten Historik. Hoffmann provides an accessible interpretation of Koselleck's oeuvre, contextualizes its insights as a reflex of the latter's experience of the abysmal crises of the twentieth century, and invites a series of far‐reaching questions that point beyond Koselleck. The significance of Koselleck for contemporary historical thought is founded on his historicization of historicism. Whereas the initial crisis of historicism constituted the point of departure for Koselleck's project, it was before the backdrop of a second crisis of historicism that he historicized historicism, embarked on a search for a theory of the conditions of possible histories, and opened up a horizon for a new historical concept of history and understanding of time.