Volume 91 of the CSEL series presents the first critical edition of Augustine's De Genesi contra Manachaeos to be based on a broad knowledge of the manuscripts. This work by the North African Father of the Church merits special interest because it records his first encounter with the biblical creation narrative. But it is also of interest because of the fact that, besides numerous connections to Augustine's other early works, ist presents some philosophical and exegetical ideas which belong to the author's enduring pattern of thought. Through a careful study of the manuscripts and occasional conjectures the text of the Maurist editors has been improved in some 350 places. A detailed survey of the manuscript tradition forms part of the introduction, which also includes an analysis of the work as well as observations concerning its sources and its reception.