Vincentius of Lérins was a Christian theologian and monk who lived in the 5th century. He is best known for his work, the "Commonitorium," which outlines principles for distinguishing true Christian doctrine from heresy. His ideas emphasized the importance of tradition and the consensus of the Church in understanding faith. Vincentius was associated with the island of Lérins, located off the coast of France, where he contributed to the development of early Christian thought. His teachings have influenced later theologians and are often referenced in discussions about the relationship between Scripture and tradition in Christianity.