Four doctors of the Church: left to right: St. Augustine, Pope St. Gregory the Great, St. Jerome, and St. Ambrose (1516), by Pier Francesco Sacchi (c. 1485–1528) [pubic domain / Wikimedia Commons]
***
[Most of the papers previously listed here in their Blogspot versions, are now uploaded to my Patheos blog: on my Fathers of the Church web page]
***