An instant is the shortest span in which time can be divided and experienced. In an instant, there is no duration: it is an interruption that happens in the blink of an eye. For the ancient Greeks, kairos, the time in which exceptional, unrepeatable events occurred, was opposed to chronos, measurable, quantitative, and uniform time. In The Moment of Rupture, Humberto Beck argues that during the years of the First World War, the Russian Revolution, and the rise of fascism in Germany, the notion of the instant migrated from philosophy and aesthetics into politics and became a conceptual framework for the interpretation of collective historical experience that, in turn, transformed the subjective perception of time.

According to Beck, a significant juncture occurred in Germany between 1914 and 1940, when a modern tradition of reflection on the instant—spanning the poetry of Goethe, the historical self-understanding of the French Revolution, the aesthetics of early Romanticism, the philosophies of Søren Kierkegaard and Friedrich Nietzsche, and the artistic and literary practices of Charles Baudelaire and the avant gardes—interacted with a new experience of historical time based on rupture and abrupt discontinuity. Beck locates in this juncture three German thinkers—Ernst Jünger, Ernst Bloch, and Walter Benjamin—who fused the consciousness of war, crisis, catastrophe, and revolution with the literary and philosophical formulations of the instantaneous and the sudden in order to intellectually represent an era marked by the dissolution between the extraordinary and the everyday. The Moment of Rupture demonstrates how Jünger, Bloch, and Benjamin produced a constellation of figures of sudden temporality that contributed to the formation of what Beck calls a distinct "regime of historicity," a mode of experiencing time based on the notion of a discontinuous present.