Est igitur et hominis quidem essentia, id est [Greek: ousia], et subsistentia, id est [Greek: ousiosis], et [Greek: hupostasis], id est substantia, et [Greek: prosopon], id est persona; [Greek: ousia], quidem atque essentia quoniam est, [Greek: ousiosis] uero atque subsistentia quoniam in nullo subiecto est, [Greek: hupostasis] uero atque substantia, quoniam subest ceteris quae subsistentiae non sunt, id est [Greek: ousioseis]; est [Greek: prosopon] atque persona, quoniam est rationabile indiuiduum. Deus quoque et [Greek: ousia] est et essentia, est enim et maxime ipse est a quo omnium esse proficiscitur. Est [Greek: ousiosis], id est subsistentia (subsistit enim nullo indigens), et [Greek: huphistasthai]; substat enim. Vnde etiam dicimus unam esse [Greek: ousian] uel [Greek: ousiosin], id est essentiam uel subsistentiam deitatis, sed tres [Greek: hupostaseis], id est tres substantias. Et quidem secundum hunc modum dixere unam trinitatis essentiam, tres substantias tresque personas. Nisi enim tres in deo substantias ecclesiasticus loquendi usus excluderet, uideretur idcirco de deo dici substantia, non quod ipse ceteris rebus quasi subiectum supponeretur, sed quod idem omnibus uti praeesset ita etiam quasi principium subesset rebus, dum eis omnibus [Greek: ousiosthai] uel subsistere subministrat. [59] quas illi _Vallinus_; quasi _uel_ quas _codd. meliores_. III. Wherefore if Person belongs to substances alone, and these rational, and if every nature is a substance, existing not in universals but in individuals, we have found the definition of Person, viz.: "The individual substance of a rational nature."[60] Now by this definition we Latins have described what the Greeks call [Greek: hupostasis]. For the word person seems to be borrowed from a different source, namely from the masks which in comedies and tragedies used to signify the different subjects of representation. Now _persona_ "mask" is derived from _personare_, with a circumflex on the penultimate. But if the accent is put on the antepenultimate[61] the word will clearly be seen to come from _sonus_ "sound," and for this reason, that the hollow mask necessarily produces a larger sound. The Greeks, too, call these masks [Greek: prosopa] from the fact that they are placed over the face and conceal the countenance from the spectator: [Greek: para tou pros tous opas tithesthai]. But since, as we have said, it was by the masks they put on that actors played the different characters represented in a tragedy or comedy--Hecuba or Medea or Simon or Chremes,--so also all other men who could be recognized by their several characteristics were designated by the Latins with the term _persona_ and by the Greeks with [Greek: prosopa]. But the Greeks far more clearly gave to the individual subsistence of a rational nature the name [Greek: hupostasis] while we through want of appropriate words