It is still uncertain if Gennadius took by mistake two Macrobiuses as one, or if indeed the later Donatist bishop of Rome was earlier an author of the "To confessors and virgins". Unfortunately, this work did not survive to our times; it was also proven that this work cannot be identified with Cyprian's De singularitate clericorum, as suggested by Harnack. One thing is certain: the Macrobius (or Macrobiuses) described by Gennadius cannot be mistaken with Macrobius, bishop of Hippona, known to us from Augustinus' letters (Epp. 106-108), and with another namesake of his, the famous author of Saturnalia.