For more than two hundred years, readers of Milton have sought to identify the theology behind Milton's representation of the Father and Son in Paradise Lost. In the wake of the recent controversy over Milton's authorship of the De Doctrina Christiana, critics have been drawn anew to the question of the way in which Milton's representation of the Son in the epic betrays a specific interest in the contemporary heresy of Socinianism, the anti-Trinitarian theology that dated the creation of the Son to the Incarnation (the Socinian Son is neither coequal or coeternal with the Father), and which confuted all orthodox understandings of the crucifixion as an event that effected either the remission of sins or the reconciliation of man and God. In a recent, splendidly comprehensive overview of the critical history of Milton's engagement with Socinianism, Michael Lieb has shown definitively that Milton, while consistently refusing to identify himself as a Socinian, manages nonetheless to engage and imitate not just the logical rigor but often even the specific arguments of this most recent flowering of anti-Trinitarian theology.

At the same time that Milton's relation to Socinianism has resurfaced as a topic of exploration, a compelling consensus has begun to emerge, or re-emerge, that Milton came to embrace many aspects of the ancient heresy of Arianism. Espousing a higher Christology than its early modern counterpart, Arianism also posited the createdness of Christ, but as Milton does in Paradise Lost, endowed him with an existence in Heaven before his incarnation as the Messiah.