The rediscovery in the fifteenth century of Lucretius’s De rerum natura was a challenge to received ideas. The poem offered a vision of the creation of the universe, the origins and goals of human life, and the formation of the state, all without reference to divine intervention. It has been hailed in Stephen Greenblatt’s best-selling book, The Swerve, as the poem that invented modernity. But how modern did early modern readers want to become? From Lucretius’ contemporary audience to the European Enlightenment, this collection of essays offers a series of case studies which demonstrates the sophisticated ways in which some readers might relate the poem to received ideas, assimilating Lucretius to theories of natural law and even natural theology, while others were at once attracted to Lucretius’s subversiveness and driven to dissociate themselves from him.