"In hunc autem errorem pessimum decidit Nestorius, ut dicit Boethius, pro eo quod nescivit distinguere inter personam et naturam. Pro eo enim quod vidit in Christo duplicem esse naturam, intellexit duplicem esse personam. Eutyches vero ex eadem causa erravit, sed non eodem modo. Quia enim nescivit discernere inter personam et naturam et vidit quod in Christo non poterat esse nisi una persona, ex hoc compulsus est ponere quod in Christo non est nisi una natura. Et ideo sicut duo fuerunt errores in divinis, scilicet Arii et Sabellii, pro eo quod nesciverunt distinguere inter naturam et personam, sic duo fuerunt errores circa incarnationem Christi, videlicet Eutychis et Nestorii. Catholica vero Ecclesia per medium istorum errorum pertransiit, dicens in deitate plures esse personas et unam naturam, et in Christo plures naturas et unam personam. Et ideo simpliciter concedit personam assumsisse naturam et negat personam assumsisse personam, sicut Magister dicit in littera."
Nestorius fell into this worst error, as Boethius says, becuase he did not know to distinguish between person and nature. For because of the fact that he saw in Christ a double nature, he understood there to be a double person. Eutyches erred for the same reason, but not in the same way; for because he did not know to distinguish between nature and person and saw that in Christ there could only be one person he was compelled to claim that in Christ there was only one nature. And therefore just as tehre were two errors in divine matters, namely of Arius and Sabellius, because they did not know to distinguish between nature and person, so there were two errors about the incarnation of Christ, namely of Eutychis and Nestorius. But the Catholic Church passes through the middle of those errors saying that there are many persons and one nature in deity, and in Christ manynatures and one person. And therefore she grants unqualifiedly that a person has assumed a nature and denies that a person has assumed a person, just as the Master says in the text.
