the controversy between Callistus and Hippolytus. We have already seen that Tertullian developed his doctrine of the Trinity in opposition to a certain Praxeas, who had established his residence in Rome and whose doctrine consisted in a Modalistic Monarchianism. Hippolytus himself develops his trinitarian doctrine in opposition to Modalism, represented in his case by Noetus of Smyrna, who, according to Hippolytus, alleged that Christ was the Father Himself, and that the Father Himself was born and