(Martin de Azpilcueta) (ca. 1491-1586), jurist and theologian, author of a series of commentaries on canon law and an influential manual for confessors, Manual de confessores y penitentes (1560).
Nestorius (fifth century), heresiarch and founder of Nestorianism, a heresy that implies some distinction between the divine Christ and the human Christ.
Netter, Thomas (Waldensis) (ca. 1370-1430), Carmelite friar, author of Doctrinale antiquitatum fidei catholicae against John Wyclif.
Nicephorus Callistus (late thirteenth century to early fourteenth century), Byzantine historian, author of Historia ecclesiastica, in eighteen books, covering until 610.
Nicholas of Cusa (Cusanus) (ca. 1401-64), philosopher and theologian. Initially he supported the conciliarist view but later changed his mind and accepted the office of papal legate (1440-47). In 1449 he was appointed a cardinal by Pope Nicholas V.
Nicholas of Lyra (ca. 1270-1340), Franciscan friar and biblical exegete. His Postillae represents a key reference for literal biblical exegesis.
Oecolampadius (Johann Heusegen) (1482-1521), Swiss reformer close to Zwingli’s position on the Eucharist and a gifted humanist scholar who collaborated with Erasmus on Erasmus’s edition of the New Testament.
Optatus of Milevis (fourth century), saint and bishop who vigorously opposed the Donatist heresy with a treatise written as a response to Parmenianus, the Donatist bishop of Carthage.
Origen, Adamantius (ca. 185-ca. 255), Father of the Church and important Neoplatonist interpreter of Christian doctrine, some of whose ideas were later declared heretical by the Christian Church. Origen’s works include De principiis, extensive commentaries on the Bible, and numerous homilies.
Otto I (Otto the Great) (912-73), Holy Roman Emperor.
Otto of Freising (ca. 1111-58), bishop and historian, author of a history of the world from creation to 1146 and of a history of Emperor Frederick I.
Panvinio, Onofrio (1530-68), monk of the Order of the Augustinian Hermits and author of numerous works, including a revision and continuation of Platina’s Liber de vita Christi et omnium pontificum.
Parmenianus (fourth century), Donatist leader, successor of Donatus as bishop of Carthage.
Paulus Aemilius Veronensis (Paolo Emilio da Verona) (ca. 1455-1529), Italian historian and author of a history of the French kings titled De rebus gestis Francorum, left unfinished.
Paulus Diaconus (Paul the Deacon) (ca. 720-99), a Benedictine monk and historian. He was the author of the Historia gentis Longobardorum and Historia Romana, which run up to the time of Justinian.
Paulus Orosius (b. ca. 380-d. after 418), Christian apologist and historian. He wrote, among other works, a Historia adversus paganos that was supposed to complement Augustine’s De civitate Dei.
Pelagius (late fourth to early fifth centuries), founder of the heresy of Pelagianism, which denied that original sin had made it impossible for humans to attain salvation without grace, but assumed that even after Adam’s fall human will was perfectly capable of wanting and accomplishing good. Pelagianism was vigorously attacked by Augustine, among others.
Peter Lombard (ca. 1100-1160), professor of theology at Paris, author of four books of Sententiae that represented a summa of Catholic theology. Before Aquinas’s Summa, Lombard’s Sententiae was the standard textbook of theology.
Petilianus (late fourth to early fifth centuries), Donatist bishop.
Petrus Bertrandus (Pierre Bertrand) (ca. 1280-1349), cardinal bishop of Autun and professor of canon and civil law in Avignon, Montpellier, Paris, and Orléans; author of several works of theology and jurisprudence, including De iurisdictione ecclesiastica et saeculari, De origine iurisdictionis, and a commentary on the Liber sextus.
Petrus de Ancharano (ca. 1333-1416), canon lawyer and jurist, pupil of Baldus de Ubaldis, and author of many commentaries on the canon law.
Philippus Caesar (Philip the Arab) (third century), Roman emperor (244-49); according to some Christian historians, including Eusebius, the first Christian emperor.
Pierre de la Palude (Paludanus) (ca. 1277-1342), patriarch of Jerusalem and Dominican theologian and canonist, whose works include the well-known De causa immediata ecclesiasticae potestatis, in which he defended the plenitudo potestatis of the pope.
Pietro del Monte (ca. 1390-1457), Venetian bishop of Brescia and humanist scholar, author of many ecclesiological works.
Pighius, Albert (Pigghe) (ca. 1490-1542), theologian and mathematician, whose works include a series of treatises in support of papal authority against Marsilius of Padua and a ten-volume treatise titled De libero hominis arbitrio et divina gratia.
Platina (Bartolomeo Sacchi) (1421-81), Italian humanist and historian, author of the well-known Liber de vita Christi et omnium pontificum, under the patronage of Pope Sixtus IV.
Pole, Reginald (1500-1558), cardinal and papal legate in England, a leading Catholic reformer and author of an important work on the role of the pope, De summo pontifice.
Priscillian (fourth century), heretic who gave the name to Priscillianism, a series of heretical doctrines under Gnostic influence.
Protagoras of Abdera (fifth century B.C.), Greek sophist and protagonist in two Platonic dialogues, the Protagoras and the Theaetetus; commonly considered the leading example of the Sophists’ ethical relativism and religious agnosticism.
Raymond le Roux (Rufus) (sixteenth century), expert on canon and civil law and jurist at the parliament in Paris, author of a treatise against Du Moulin (1553).
Raymond of Peñafort (ca. 1175-1275), general of the Dominicans and a great canonist. He was in charge of the commission set up by Pope Gregory IX to complement and correct the main collection of Decretals, the Quinque compilationes antiquae, and he collected and edited the Liber extra of decretals, the resulting work known as Decretales Gregorii IX of 1234 (cf. Boniface VIII). He was also the author of an important manual for confessors titled Summa de poenitentia, sive casuum.
Regino of Prüm (d. ca. 915), Benedictine abbot and author of a universal chronicle.
Richard of Middleton (Ricardus de Mediavilla) (d. ca. 1305), Franciscan theologian and author of an influential commentary on Peter Lombard’s Sen tentiae.
Roger of Hoveden (d. ca. 1201), chronicler and one of the king’s clerks under Henry II. His Annals covered the history of England from 732 to 1201.
Rufinus, Tyrannius (Rufinus of Aquileia) (ca. 345-410), theologian best known as translator into Latin of Origen’s De principiis and Eusebius’s Historia.
Sander, Nicholas (1530-81), English theologian at the University of Louvain, author of De visibili monarchia ecclesiae, a treatise defending papal authority in temporal matters, and of the unfinished De schismate Anglicano, a historical work on the progress of the Reformation in England.
Sebadius (Sabadius or Foebadius) (fourth century), bishop of Agen and author of a treatise against Arianism, Contra Arianos.
Servetus, Michael (1511-53), Spanish physician, theologian, and humanist who elaborated an anti-Trinitarian theology and argued for a form of religious toleration. Hated with equal vigor by Protestants and Catholics alike, Servetus was executed in Geneva by order of Calvin.
Sigebert of Gembloux (ca. 1035-1112), Benedictine monk and historian and author of a Chronicon of the history of the world.
Simancas, Jacobus (Didacus) (1513-83), theologian, canonist, and bishop successively of Ciudad Rodrigo, of Badajoz, and of Zamora, whose works include De Catholicis institutionibus.
Socrates Scholasticus (fifth century), historian of the Christian Church who continued Eusebius’s Historia ecclesiastica until the middle of the fourth