Needless to say, the claims of your son’s professor—that Nicaea was merely the scene of a political power-play and that the Christianity “invented” by Constantine and his henchmen was not, and is not, the only option—are far from surprising; it’s the usual classroom fare these days: there are Christianities, Hinduisms, Judaisms, and so forth because professors of religion seem no longer capable of seeing the forest for the trees; as far as I can tell, they wouldn’t recognize an essence if it struck them in the face, as by all rights it ought to!
I’m not sure I would have responded, or rather suggested responding, in so exclusively historical or sociological a way, however. Informing this young man—and his politically fashionable teacher—of the facts of Church history is certainly important, but these facts are rooted after all in an experience in which we may all participate, verifying in our own persons the fundamental claim of the Tradition: “God became man that man might become God.”
I believe you’ve read the on-line lectures for my Christian Theology course at USC. You might have your son take a look at Lecture 12 in particular, “The Logic of Nicaea”. To quote myself briefly:
“Rather than engaging in a skeptical dismissal of the matter [as your son’s professor clearly has] and rather than resting in pious statements of praise [as you may be tempted to do], we need to focus our attention on the theological ‘logic’ of the claim [that Christ is ‘of one essence with the Father’]….
The closer one looks at this issue, and the more one reads the writings of early theologians (like St Athanasius) who were close to the whole dispute, the clearer it seems that the Council of Nicaea ended up making this change [that is, adding the term homoousion to the earlier Creed of Caesarea] and insisting on Christ’s deity for specific theological reasons.
Whatever the ‘political’ context might have been and whatever the human or Divine explanation for the (apparently) sudden and surprising turn-around in that Turkish summer of A.D. 325, the logic behind the new creed is clear” (p. 121).
The logic in question, as I go on to point out, is clearly rooted in the experience of theosis—in the regenerative power that flows from participation in Christ, who cannot but be God if the effects He produces are so obviously Divine. Athanasius cut straight to the heart of the matter in his biography of his spiritual master: “If Christ isn’t God, how do you explain Anthony?!”