Ambrosiaster or Pseudo-Ambrose is the name given to the unknown author of a commentary on the epistles of Saint Paul, written some time between 366 and 384AD. This commentary was erroneously attributed for a long time to St. Ambrose, hence the name "Ambrosiaster" (literally in Latin: "would-be Ambrose"). Various conjectures have been made as to Ambrosiaster's true identity, and several other works have been attributed to the same author, with varying degrees of certainty. Biography Pseudo-Ambrose was the name given by Erasmus to refer to the author of a volume containing the first complete Latin commentary on the Pauline epistles. Alexander Souter has established that the same author wrote the Quaestiones Veteris et Novi Testament, which had long been attributed to Saint Augustine. Other works ascribed to the same author, less definitely, are the Lex Dei sive Mosaicarum et Romanorum legum collatio, De bello judaico, and the fragmentary Contra Arianos sometimes ascribed to the pseudo-Hilary and the sermo 246 of pseudo-Augustine. They mention Simon Magus. Internal evidence from the documents has been taken to suggest that the author was active in Rome during the period of Pope Damasus, and, almost certainly, a member of the clergy. Commentary on Paul The Commentary on Thirteen Pauline Letters is considered valuable as evidence of the state of the Latin text of Paul's epistles before the appearance of the Vulgate of Jerome, and as an example of Pauline interpretation prior to Augustine of Hippo. It was traditionally ascribed to Ambrose, but in 1527, Erasmus threw doubt on the accuracy of this ascription, and the anonymous author came to be known as "Ambrosiaster". It was once thought that Erasmus coined this name; however, René Hoven, in 1969, showed that this was incorrect, and that credit should actually be given to the Maurists. Later scholars have followed Hoven in this assessment, although it has also been suggested that the name originated with Franciscus Lucas Brugensis. Attempts to identify Ambrosiaster with known authors has continued, but with no success. Because Augustine cites Ambrosiaster's commentary on Romans 5:12 under the name of "Hilary", many critics have attempted to identify Ambroasiaster with one of the many writers named "Hilary" active in the period. In 1899, Germain Morin suggested that the writer was Isaac, a converted Jew and writer of a tract on the Trinity and Incarnation, who was exiled to Spain in 378-380 and then relapsed to Judaism. Morin