Theorists have distinguished ‘positive’ and ‘negative’ forms of retributivism. Positive retributivism holds that an offender’s desert provides a reason in favour of punishment; essentially, the state should punish those found guilty of criminal offences to the extent that they deserve, because they deserve it. Penal desert constitutes not just a necessary, but an in-principle sufficient reason for punishment (only in principle, however, since there are good reasons — to do with the costs, both material and moral, of punishment — why we should not even try to punish all the guilty). Negative re...