Abstract
The retributive sentiments require justification: blame, resentment and indignation are costly, and it is not analytic that respect for a norm includes resenting its violation. Working from the outside in, I argue that the retributive sentiments are possible only if, and because, cooperation is possible, and that conformity-biased cultural transmission explains how a disposition to third-party punishment can be individually rational despite the standing incentive to free ride. The second half of the paper turns to the implications for legal and political philosophy, contrasting the cooperative architecture of informal social order with that of formal, rule-governed institutions, and asking how the two interact in criminal justice.