Hermann Karl Usener (1834–1905) published his monumental Epicurea in 1887. The volume is a collection of Epicurean texts and citations from a wide range of classical authors including Arrian, Cicero, Diodorus, Euripides, Plato and Seneca. The volume includes critical texts of Epicurus' most important letters: Letter to Menoeceus, Letter to Herodotus and Letter to Pythocles, preserved by the third-century compiler Diogenes Laertius. The letters give important summaries of Epicurus' philosophy. Usener's pioneering work represented the first attempt to deal critically with the manuscript traditions behind Epicurean texts. His reconstructions of the texts included in this volume are based on a thorough understanding of the trajectories of textual transmission. Each text is supported by a detailed critical apparatus, and another apparatus records manuscript glosses and scholia. This work provided for the first time accurate and reliable texts for the critical study of Epicureanism.