This is the first scholarly commentary on Cicero's Divinatio in Caecilium and the first new critical edition in over 100 years. The commentary demonstrates that the Divinatio was atypical of the genre. In both form and content, the speech is styled as a forensic prosecution rather than a pre-trial deliberation. It also functions as an effective piece of literary criticism and a pedagogical treatise to preface the Verrine corpus. Consequently scholars are encouraged to reconsider how published oratory in Rome functioned as teaching aid, personal propaganda, historical record, and literary production. The Divinatio touches on issues with strong resonance for contemporary society: the responsibility of the government to represent and defend marginalised communities, cultural identity and integration in a multi-ethnic society, the perils of persuasive speech, abuses of political and military power, due process of law, and changing notions of intellectual and cultural property.