John Scotus Eriugena, also known as Johannes Scotus Erigena, John the Scot, or John the Irish-born (c. 800 – c. 877) was an Irish Neoplatonist philosopher, theologian and poet of the Early Middle Ages. Bertrand Russell dubbed him "the most astonishing person of the ninth century".
John Chrysostom (/ ˈ k r ɪ s ə s t ə m, k r ɪ ˈ s ɒ s t ə m /; Greek: Ἰωάννης ὁ Χρυσόστομος; c. 347 – 14 September 407) was an important Early Church Father who served as archbishop of Constantinople.
John of Ávila (Spanish: Juan de Ávila; 6 January 1499 – 10 May 1569) was a Spanish priest, preacher, scholastic author, and religious mystic, who has been declared a saint and Doctor of the Church by the Catholic Church.
Fulton John Sheen (born Peter John Sheen, May 8, 1895 – December 9, 1979) was an American bishop of the Catholic Church known for his preaching and especially his work on television and radio.
John Christopher "Aidan" Nichols OP (born 17 September 1948) is an English academic and Catholic priest. Nichols served as the first John Paul II Memorial Visiting Lecturer at the University of Oxford for 2006 to 2008, the first lectureship of Catholic theology at that university since the Protestant Reformation .
Summa Theologica, 1596 Theology is the most certain of all sciences because its source is divine knowledge (which cannot be deceived) and because of the greater worth of its subject matter, the sublimity of which transcends human reason .
John Duns Scotus OFM (c. 1265/66 – 8 November 1308), commonly called Duns Scotus (/ ˈ s k oʊ t ə s / SKOH-təs; Ecclesiastical Latin: [duns ˈskotus]; "Duns the Scot"), was a Scottish Catholic priest and Franciscan friar, university professor, philosopher, and theologian.