This book argues that the mass is the most characteristic socio-historical feature of our century. Kierkegaard was the first to anticipate and delineate this phenomenon philosophically. Heidegger appropriated much from Kierkegaard, but recast the mass into the fundamental ontology of . Moreover, his work was informed by Nietzsche’s understanding of nihilism and the will of power. Finally, the masses are considered from the vision of Ortega y Gasset’s philosophy of human life. This book relates all four of these thinkers into a philosophical perspective upon the nature of the mass.