other · 434 · Lérins Islands
The formula — quod ubique, quod semper, quod ab omnibus — is the most quoted sentence any fifth-century Latin wrote, and it is usually quoted without the rest of the argument, which is the interesting part. Vincent knew perfectly well that the first test does not always give an answer, so he adds a second: where the whole church has not spoken, follow the majority of the fathers, and where they disagree, follow what the councils defined. And he grants outright that doctrine develops — it grows as a body grows, he says, remaining the same thing at every stage. The book is signed Peregrinus, the pilgrim, and its target is nowhere named. He was writing three years after the Council of Ephesus, at a monastery whose men were the sharpest critics of Augustine on grace, and a long tradition reads it as aimed partly at Augustine — which the pseudonym would explain. Gennadius, a presbyter of the same coast writing within living memory, is the earliest witness to both the book and its odd condition: "The greater part of the second book of this work having been stolen, he composed a brief reproduction of the substance of the original work." What survives is that summary.
How do you tell the faith of the church from something somebody has just thought of?
What has been believed everywhere, always, and by everyone. Then a second test for when that fails.