Against Capital Punishment offers an innovative proceduralist argument against the death penalty. Worries about procedural injustice animate many popular and scholarly objections to capital punishment. Philosophers and legal theorists are attracted to procedural abolitionism because it sidesteps controversies over whether murderers deserve death, holding out a promise of gaining rational purchase among death penalty retentionists. Following in this path, the book remains agnostic on the substantive immorality of execution; in fact, it takes pains to reconstruct the best arguments for capital punishment and presumes the appropriateness of execution in limited cases. At the same time, the book contends that the possibility of irrevocable mistakes precludes the just administration of the death penalty. The heart of Against Capital Punishment is a philosophical defense of the well-known irrevocability argument, which analyzes the argument’s premises, establishes their validity, and vindicates them against objections. The central claim is that execution violates the principle of remedy, which requires legal institutions to remedy their mistakes and to compensate those who suffer from wrongful sanctions. The death penalty is repellent to the principle of remedy by dint of its irrevocability. The incompatibility of remedy and execution is the crux of the irrevocability argument: because the wrongly executed cannot enjoy the obligatory remedial measures, execution is impermissible. Against Capital Punishment also reveals itself to be free from two serious defects plaguing other versions of proceduralism: the retributivist challenge and the problem of controversial consequences.