 The question of whether, and how, legal punishment can be justified has long been a central concern of legal, moral, and political philosophy: what could justify a state in using the apparatus of the law to inflict intentionally burdensome treatment on its citizens? Radically different answers to this question are offered by consequentialist and by retributivist theorists — and by those who seek to incorporate consequentialist and retributivist considerations in ‘mixed’ theories of punishment. Meanwhile, abolitionist theorists argue that we should aim to replace legal punishment rather than to justify it. Among the significant developments in recent work on punishment theory are the characterisation of punishment as a communicative enterprise, greater recognition that punishment’s justification depends on the justification of the criminal law more generally, growing interest in the normative challenges raised by punishment in the international context, and increased concern for the relationship of punishment to the so-called ‘collateral’ consequences of a conviction.