Latinizzato in Cornelius Iansenius. Nessuna notizia biografica in italiano reperibile nel web, eccetto il fatto che fu vescovo di Gand, che si trova nel Belgio settentrionale ed è capoluogo della provincia della Fiandra Orientale, detta Gent in fiammingo e Gandavum Castrum nel secolo VII. A Gand nell’anno 1500 nacque il futuro imperatore Carlo V. Cornelis Jansen scrisse Commentariorum in suam concordiam ac totam historiam evangelicam partes quatuor edito per la prima volta a Lovanio nel 1558, con numerose riedizioni, tra cui una del 1579 a Venezia, reperibile presso la biblioteca di Empoli.
Questo Jansen Cornelis non va confuso con il suo perfetto omonimo teologo fiammingo (Ackow 1585 - Ypres 1638) che, nominato vescovo di Ypres nel 1635, vi morì di peste tre anni dopo, e che, involontario fondatore del giansenismo, fu autore di una famosissima opera intitolata Augustinus.
Cornelius Jansen, the Elder (born at Hulst, Flanders, 1510; died at Ghent, 11 April 1576) was a Flemish Catholic exegete. He received his early education at Ghent from the Brethren of the Common Life (called at Ghent the Hieronymites), and later studied theology and Oriental languages at Leuven. After he had become a licentiate of theology in 1534, he lectured, at the request of the abbot of the Premonstratensian Abbey of Tongerloo, to the young monks on the Holy Scripture until 1542, from which date until 1562 he discharged the duties of pastor of the parish of St. Martin at Courtray (Kortrijk) with great success.
Having finally attained the degree of Doctor of Theology in 1562, he was immediately appointed professor of theology at the University of Leuven, became in the following year dean of the collegiate seminary of St. James, and attended the last sessions of the Council of Trent as delegate of the university.
On his return, Philip II of Spain appointed him first bishop of the newly founded See of Ghent, which dated only from 1559. For a long time he refused to assume the dignity, on account of the difficult conditions in the diocese, and was not preconized until 1568, by Pope Pius V. As bishop he devoted himself especially to checking the advance of Protestantism, and to carrying out the decrees of the Council of Trent. With this object in view, he founded a seminary for priests at Ghent in 1569, held diocesan synods in 1571 and 1574, and published a ritual for his diocese.
He was entrusted with the compilation of a ritual to be used in the ecclesiastical province of Mechlin, but did not finish it. While at Tongerloo he wrote a great deal, and, as pastor at Kortrijk, had already become widely known for his exegetical work.
Among Jansen's writings is the "Concordia evangelica." (Leuven, 1529), to which he later added the "Commentarius in Concordiam et totam historiam evangelicam" (Leuven, 1572), undoubtedly his best work. He published also: "Commentarius in Proverbia Salomonis" (Leuven, 1567), and "Commentarius in Ecclesiasticum" (Leuven, 1569), both of which were republished in one work at Antwerp in 1589; "Commentarius in omnes Psalmos Davidicos" (Leuven, 1569), with an introduction to each psalm, an excellent paraphrase of the text, and explanations of the difficult passages; "Paraphrases in ea Veteris Testamenti Cantica, quae per ferias singulas totius anni usus ecclesiasticus observat" (Leuven, 1569). After his death appeared "Annotationes in Librum Sapientiae" (Leuven, 1577).
Cornelius Jansen was one of the most distinguished among the exegetes of the sixteenth century, and the Concordia Evangelica was epoch-making in the history of Catholic exegesis, for he insisted on the literal interpretation, as against the mystical interpretation of his predecessors, emphasized also the importance of the original text, and of a profound study of Oriental languages as aids to a full comprehension of the Latin Vulgate.