More than any other 20th-century philosopher, Deleuze considers himself an apprentice to the history of philosophy. But scholarship has ignored one of the more formative influences on Deleuze: Lucretian atomism. Deleuze's encounter with Lucretius sparked a way of thinking that resonates throughout all his writings: from immanent ontology to affirmative ethics, from dynamic materialism to the generation of thought itself. Filling a significant gap in Deleuze Studies, Ryan J. Johnson tells the story of the Deleuze-Lucretius encounter that begins and ends with a powerful claim: Lucretian atomism produced Deleuzianism.