Abstract
In a remarkable series of papers, Haugeland lays out what is both a striking interpretation of Heidegger and a compelling account of objectivity and truth. Central to his account is a notion of existential commitment: a commitment to insist that one's understanding of the world succeeds in making sense of the phenomena and so potentially to change or give up on that understanding in the face of apparently impossible phenomena. Although Haugeland never gives a clear account of existential commitment, he claims that it is fundamentally an individual matter. This, I argue, is a mistake that fails to make sense of the public, shared nature of the objective world. Instead, I offer an account of existential commitment as one we undertake *jointly*, and I analyze it (and the corresponding responsibility) in terms of interpersonal rational patterns of reactive attitudes: emotions like resentment, gratitude, indignation, approbation, guilt, and trust. The upshot is that our existential commitment is not only to a shared, objective world but also to each other such that our ability individually to *take* responsibility for our understanding of the world is intelligible only in terms of others' being able to *hold* us responsible for it.