Book 2, Chapter 56
At the same time a certain Vincentius Victor in Mauretania Caesariensis came upon one of my works in the possession of a certain Peter, a Spanish presbyter. [...]
Subsequently, Vincentius Victor, a layman, wrote to Peter (who came from Spain, but was probably settled in Mauretania) a book against Augustine's thesis on the immateriality of the soul. Augustine wrote in response "The Nature and Origin of the Soul".
(trans. B. Ramsey; summary by S. Adamiak)