In Against Heresies, Irenaeus is renowned for formulating points of doctrine (e.g., "recapitulation" and the regula veritatis) that would be of great import in the development of early Christian thought. This thesis proposes that Irenaeus' contribution to theological hermeneutics is no less significant. In our first chapter, we argue that scholarship in the wake of Adolf Harnack has tended to inflate Irenaeus' notion of recapitulation without proper warrant. A more modest approach to recapitulation illuminates the primary context of this term: Irenaeus' bias toward origins and his corresponding use of Genesis creation texts to construct theology. Since the battle which Irenaeus engaged was principally a competition over how to read biblical texts as Christian Scripture, chapter two surveys his opponents. With an eye toward hermeneutical method, we detail and assess Valentinian interpretations of Genesis, as well as the dramatic readings of the "Ophites" which may have exerted a contributory influence. Chapters three and four examine Irenaeus' own theological uses of Genesis, particularly of two focal texts, Genesis 1.26 and 2.7. For Irenaeus, the imago Dei motif was well-suited for elaborating a comprehensive vision of God's economy because it could be used flexibly to locate humanity inside its span: from human origination, through fall and restoration, to eschatological destiny. The "breath of life" text was found conducive for exceptionally wide typological readings. By using it to paint a portrait of God, Irenaeus also aims to supply a more satisfying anthropological sketch than the Valentinians can offer. The purposeful work of the Father, through his two hands (Son and Spirit), will present the human creation as fully alive - in body no less than soul. In the end, this thesis points to the contemporary relevance of Irenaeus' hermeneutic, his view of protology, and his non-Platonic anthropology.