Following the lead of ancient heresiologists, modern scholars have all too often viewed Valentinus and Heracleon as representatives of a unified sectarian group whose interpretations of early Christian literature were determined by a shared set of "heretical" views. Arguing that the exegetical methodology of early Christians may be better understood if viewed within the larger context of Greco-Roman literary criticism, this article studies how Valentinus and Heracleon use one passage of early Christian literature to illuminate another, and compares this practice to the principle of Aristarchus, which states that Homer should be clarified from Homer.