The studies collected in this volume were published by Anna Maria Ioppolo over the course of some thirty years and constitute an important milestone in recent research on ancient thought. They reflect the renewed interest in Hellenistic philosophies which emerged in the 1980s. Through a rigorous application of the historical and philological method of the Italian historical school, with its focus on the sources and original texts, a careful and detailed reconstruction is provided of the arguments and debates that shaped the philosophical schools of the Hellenistic and Imperial age, while at the same time engaging in the kind of theoretical investigations which are usually provided by more analytical investigations. The subjects discussed include topics of great relevance for Hellenistic and Imperial-age philosophies, such as assent, the passions, the Stoic doctrine of causality in its different versions, the polemics between Academics and Sceptics, and astrology. Alongside well-known names (Arcesilaus, Carneades, Cicero, Seneca), these studies cover a range of apparently minor figures and currents (Herillus, Favorinus, the neoteroi Academics) whose historical and philosophical framing has crucially contributed to the drawing of an exhaustive, all-round picture of Hellenistic and Imperial-age philosophy.