b. To the First Reason

257. To the first reason, about the necessity of positing several things [nn.205-206], I say that although this cannot be proved with evident necessity from things believed, yet there is a necessity to posit what the Church posits. And there are the congruences of the sort before adduced [nn.247-249]. Nor is the negative argument valid, ‘if not Augustine nor Dionysius nor Damascene, therefore no one’ [nn.208-218]; for the authority of the Church is sufficient, because Augustine On the Morals of Manichaeans [actually Against the Letter of Manichaeus they call Fundamental ch.5 n.6] says, “I would not believe the Gospel unless I believed the Church” [more correctly: “But I would not believe the Gospel unless the authority of the Catholic Church moved me”].