One major argument against prohibiting euthanasia and physician-assisted suicide (PAS) is that there is no rational basis for distinguishing between killing and allowing to die: if we permit patients to die by forgoing life-sustaining treatments, then we also ought to permit euthanasia and PAS. In this paper, the author argues, contra this claim, that it is in fact coherent to differentiate between killing and allowing to die. To develop this argument, the author provides an analysis of Saint Augustine’s distinction between martyrdom and suicide, highlighting the relevance of intention in the assessment of an agent’s actions. As a general matter of ethics, the intentions of agents, not just the outcomes of their actions, matter enormously for drawing distinctions between what is permissible and what is impermissible. Constructing an Augustinian account of this distinction between killing and allowing to die, the author argues that it is coherent to hold that assisted suicide is wrong, while also accepting that it is permissible to withhold or withdraw life-sustaining treatments.