The first part of this paper looks into the question of Lucretius’ philosophical sources and whether he draws almost exclusively from Epicurus himself or also from later Epicurean texts. I argue that such debates are inconclusive and likely will remain so, even if additional Epicurean texts are discovered, and that even if we were able to ascertain Lucretius’ philosophical sources, doing so would add little to our understanding of the De Rerum Natura. The second part of the paper turns to (...) a consideration of what Lucretius does with his philosophical sources. The arguments within the De Rerum Natura are not original. Nonetheless, the way Lucretius presents these arguments establishes him as a distinctive philosopher. Lucretius deploys non-argumentative methods of persuasion such as appealing to emotions, redeploying powerful cultural tropes, and ridicule. These methods of persuasion do not undercut or displace reasoned argumentation. Instead, they complement it. Lucretius’ use of these methods is rooted in his understanding of human psychology, that we have been culturally conditioned to have empty desires, false beliefs, and destructive emotions, ones that are often subconscious. Effective persuasion must take into account the biases, stereotypes, and other psychological factors that hinder people from accepting Epicurus’ healing gospel. (shrink)