Martin Heidegger's 1927 publication, Sein und Zeit: Erste Hälfte (translated as Being and Time, 1962), can plausibly be considered the most influential philosophical text of the twentieth century. Its main focus had been announced at least fifteen years earlier when Heidegger was still in his early twenties, and it remained his lifelong topic until his death in 1976. He treated this subject matter in several ways, beginning with concepts of phenomenology, such as life, world, historicity, and facticity, which were illuminated by what he called the question of being. Later he developed this topic as das Ereignis, "the event of appropriation," which designates the singular unfolding of being. The topic, in short, concerns how human beings are situated historically in a world that from the beginning has some meaning for them, both making possible and setting limits to their future. Sein und Zeit emerged as a seamless amalgamation of...