Eight writings by Ptolemy have survived: •
De iurisdictione imperii et auctoritate summi pontificis (On the Jurisdiction of the Empire and the Authority of the Highest Pontiff), also called
Determinatio compendiosa de iurisdictione imperii •
De operibus sex dierum (On the Works of the Six Days), also called
Exameron •
De regimine principum (On the Government of Rulers) •
Annales (Annals) •
De origine ac translatione et statu Romani Imperii (On the Origin and Translation and State of the Roman Empire) •
De iurisdictione ecclesiae super regnum Apuliae et Siciliae (On the Jurisdiction of the Church over the Kingdom of Apulia and Sicily) •
Historia ecclesiastica nova (New Ecclesiastical History) • A brief letter co-written with Prosper of Pistoia in 1307 In addition to these surviving writings, there are several
cited but non-extant works of Ptolemy: •
Historia tripartita (Three-Part History), perhaps unfinished •
Historia quadripartita (Four-Part History), perhaps unfinished •
Catalogus imperatorum (Catalogue of the Emperors), perhaps merely planned but never written Ptolemy also planned to write treatises on moral philosophy, household management and the virtues of rulers, but there is no evidence he ever did. The best-known work of Ptolemy is his
Annales (1061–1303), finished about 1307, wherein are recorded in terse sentences the chief events of this period. His
Historia Ecclesiastica Nova in twenty-four books relates the history of the Church from the birth of
Christ till 1294; considering as appendixes the lives of
Pope Boniface VIII,
Pope Benedict XI, and
Pope Clement V, it reaches to 1314 (
Muratori, loc. cit., XI, 751 sqq.; the life of Clement V is in
Baluze,
Vitae pap. Aven., 23 sqq.). He also wrote a
Historia Tripartita known only from his own references and citations. The
Extract[us] de chronico Fr. Ptolomaei de Luca and the
Excerpta ex chronicis Fr. Ptolomaei are no longer considered original works by separate authors, but are extracts from the
Historia Ecclesiastica Nova by some unknown compiler who lived after the death of Ptolemy. He is also well known for his completion of the
De Regimine Principum ("On the Government of Rulers"), which Aquinas had been unable to finish before his death. This was no small task, for the share of Ptolemy begins with the sixth chapter of the second book and includes the third and fourth books (vol. XVI, in the Parma, 1865, edition of Aquinas). Though he does not follow the order of the saint, yet his treatment is clear and logical. A committed
republican, Ptolemy was central to developing a theory for the practices of Northern Italian republicanism and was the first writer to compare
Aristotle's examples of
mixed constitutions -
Sparta,
Crete, and
Carthage - with the
Roman Republic, the ancient Hebrew polity, the
Church, and
medieval communes, yet he remained a staunch defender of the absolute secular and spiritual monarchy of the pope. A work on the
Hexaemeron by him was published by Masetti in 1880. The lives of the
Avignon popes were written from original documents under his hands and were controlled by the statements of eyewitnesses. His acceptance of
fables now exploded, e.g. the
Popess Joan, must be attributed to the uncritical temper of his time. ==Editions==