Hierarch Vincent of Lérins

Venerable Vincent of Lérins was born in Gaul, likely in Toulouse or Toul, and was the brother of St. Lupus of Troyes. Leaving a military career, he embraced monastic life at the renowned Abbey of Lérins, where he was ordained a priest. Around 434, under the pseudonym Peregrinus, he wrote the "Commonitorium" ("Memoranda"), in which he formulated the famous rule known as the "Vincentian Canon" for distinguishing true church Tradition from heresy: "what has been believed everywhere, always, by all" (quod ubique, quod semper, quod ab omnibus creditum est). This principle became a foundational criterion of catholicity in Christian doctrine. He died around 445.