How much a life is worth?

What gives anyone the authority to decide that someone else must bear the cost of saving, protecting, or sparing a life? This essay argues that the value of a life does not, by itself, confer on anyone else the right to dispose of it, and that whoever imposes a sacrifice, excludes someone from an essential resource, prohibits a choice, or authorizes an irreversible act must justify that decision to those who bear its cost. Drawing on Singer's drowning-child case, Baggini's pig that wants to be eaten, the film Deep Impact, and the problem of hostage-taking, the essay derives a criterion of proportionate justification, concerning the existence of the problem, the effectiveness of the measure, the necessity of the sacrifice, and the absence of less burdensome alternatives, and grounds it in a premise about the justification owed to those on whom a power operates. It then tests the criterion on medical assistance in dying, distinguishing the risk of authorizing a death that is not freely willed from the risk of denying or delaying assistance to a person who requests it freely and persistently, and it considers the objection from the unavailability of life (Finnis, Campbell). Canadian monitoring data for 2024 are used cautiously, to identify what safeguards would have to address rather than to settle the normative question. The essay defends a standard of justification, not a verdict on any particular legal regime.