In 1827 Cardinal Mai printed un his Scriptorum Veterum Nova Collectio the fragments of a dialogue in Greek "On political science" which appears to be partly based on Plato’s Republic and partly on Cicero’s De Republica. He ascribed these fragments, probably in error, to a certain Peter who held the post of magister officiorum under the emperor Justinian I; and he did so on the ς επιστημ̃assumption that the dialogue (entitled in Greek περί πολιτικη̃ης) was identical with a work, entitled περί πολιτικη̃ς καταστασέως, which is ascribed to this Peter in the lexicon that goes by the name Suidas. But the work of Peter dealt with political institutions, and not with political science; and there is thus no valid reason for the identification suggested by Mai. Another suggestion which he made has more probability, though it, too, is not without difficulties. This suggestion is that the dialogue on political science is to be identified with a work mentioned by Photius in his Myriobiblion as having been read in the circle which gathered in his house for study. Today we can only say that we are dealing with an unknown author, who wrote at an unknown date. But it is possible to suggest an approximate date at which the dialogue may have been written: in the sixth century during the reign of Justinian.