[In his encyclical Fides et ratio, John Paul II favorably cited Antonio Rosmini. Since many propositions taken from Rosmini’s thought had been proscribed by the 19th-century magisterium, such citation called for a rethinking on the part of the Congregation for the Doctrine of the Faith. In a Note issued in 2001, its prefect, Joseph Ratzinger, explained how the earlier censure of Rosmini could now be reconciled with his current rehabilitation. Using categories drawn from Thomas Kuhn, the present article examines the Note and its admissions regarding paradigm-based rationality.]