Vincent of Lérins, a fifth-century monk, is best known today for two principles. The first is that true Christian doctrine is that which has been believed everywhere, always, by everyone. The second is his idea that Christian doctrine grows and develops, yet is not altered.
Essay on the fifth-century monk and ecclesiastical writer.
Catholic Online: St. Vincent of Lerins
Paragraph more about his famous "quod ubique, quod semper, quod ab omnibus" than about Vincent himself.
Introduction to the Commonitory of Vincent of Lérins
By C.A. Heurtley, in the Nicene and Post-Nicene Fathers of the Christian Church, Second Series, vol. 11.
Orthodox America: St. Vincent of Lerins
Short biography of a leading theologian of the Church of Gaul in the 5th century with a few quotes.