2. A physician, whose father, Philostorgius, lived in the time of Valentinian and Valens, in the latter half 'of the fourth century after Christ : the brother of the physician Posidonius (Philostorg. Hist. Eccles. 8.10). Fabricius conjectures that he may be the same person to whom are addressed eight of the letters of St. Gregory Nazianzen (Bibl. Graec. vol. xiii. p. 364, ed. vet.). This is quite possible, but at the same time it may be stated that the writer is not aware of there being any reason for supposing St. Gregory's correspondent to have been a physician.