What Happened in and to Moral Philosophy in the Twentieth Century? is a volume of essays originally presented at University College Dublin in 2009 to celebrate the eightieth birthday of Alasdair MacIntyre—a protagonist at the center of that very question. What marks this collection is the unusual range of approaches and perspectives, representing divergent and even contradictory positions. Such variety reflects MacIntyre's own intellectual trajectory, which led him to engage successively with various schools of thought: analytic, Marxist, Christian, atheist, Aristotelian, Augustinian, and Thomist. This collection presents a unique profile of twentieth-century moral philosophy and is itself an original contribution to ongoing debate. The volume begins with Alasdair MacIntyre's fascinating philosophical self-portrait, "On Having Survived the Academic Moral Philosophy of the Twentieth Century," which charts his own intellectual development. The first group of essays considers MacIntyre's revolutionary contribution to twentieth-century moral philosophy: its value in understanding and guiding human action, its latent philosophical anthropology, its impetus in the renewal of the Aristotelian tradition, and its application to contemporary interests. The next group of essays considers the complementary and competing traditions of emotivism, Marxism, Thomism, and phenomenology. A third set of essays presents thematic analyses of such topics as evolutionary ethics, accomplishment and just desert, relativism, evil, and the inescapability of ethics. MacIntyre responds with a final essay, "What Next?," that addresses questions raised by contributors to the volume.