This new critical edition aims to provide a new standard text of Apuleius' De Deo Socratis, De Platone et eius dogmate, and De mundo, allowing readers to get closer than ever before to the philosophical writings of the renowned orator, extraordinary prose stylist, and Platonist philosopher. Knowledge of these three works is crucial to understanding the reinterpretation and transmission of Greek philosophical thought in the Latin world: based on a new collation of the ancient manuscripts and scrupulous investigation of all previous editions, the Latin text presented here relies on a safer ms. basis than its predecessors. The enforcement of the criterion of the so-called 'signal-word' in particular has enabled improved solutions for many textual problems to be0found, some older emendations to be confirmed, and previously unnoticed corruptions to be located and cogently healed, while the rich and detailed apparatus criticus selectively focuses on only plausible conjectures in doubtful passages. A fluent Latin praefatio offers a neat explanation of the principles which have been adopted throughout the edition, while also ably balancing comprehensive coverage of the main manuscript sources, their histories, and their relationships with lucidity and concision, despite the intricacy of the textual tradition.