 Lex talionis provides a controversial principle of proportionality (for more on lex talionis as a measure of proportional punishment, see section 2 of the supplementary document  Challenges to the Notion of Retributive Proportionality).  But while retributive justice includes a commitment to punishment that is proportional to the crime, it cannot be reduced to a measure of proportionality (Moore 1997: 88; Husak 2019).