Janssenboy the family name of several Dutch theologians quite distinguished in the Roman Catholic Church, mostly as missionaries of the Dominican order.
1. CORNELIUS, born near the beginning of the present century, was educated at Louvain, then went to Italy, and, after preaching and teaching for some time, the Congregation of the Propaganda sent him in 1623 to the northern provinces on mission work, and, as his especial field, Saxony was designated. Failing, however, to make many converts in this country, the very cradle of Protestantism, he was ordered to remove to Flanders. On his return to Italy in 1637, he was lost at sea (Oct. 11). He wrote several works of some note, mostly of a polemical nature, amongst which, of especial interest to us, his Defense de la Foi Catholique.
2. DOMINICUS, brother of the former, born at Amsterdam March 14, 1647, was also dispatched to the northern provinces at the same time as his brother Cornelius. He resided at Hamburg, but the opposition he here encountered by imprudent conduct finally resulted in his expulsion from the city; and although the order was afterwards revoked, by reason of his pledges to be more considerate and fair in his representations of the Reformers, he quitted Hamburg in 1634 ad retired to a Dominican convent at Cologne. In 1643 his superiors sent him to Amsterdam, where he died March 14,1647. While at Cologne, Dominicus published several works in defence of the doctrines and usages of the Roman Catholic Church, but they are rather of an inferior order.
3. NICHOLAS was born at Zierickzee, on the island of Schouwen, Zealand, in the second half of the 16th century. After having taken the Dominican garb at Anivers, he was appointed regent and then superior of the college at Lire, in Brabant, and afterwards professor of theology at Louvain. His superior ability pointed him out as one of the ablest men for missionary labor among the Lutherans of Denmark, and he was intrusted with this work. After a stay of several years in Holstein, Norway, and other northern provinces, he went to Rome to give an account of his labors, and to propose the measures necessary to re-establish Romanism in those countries. In 1623 he was again dispatched to the same countries, this time reinforced by his brothers above mentioned. He failed, however, in making much of an impression on the Protestants, who had heard and seen enough of Romanism and its workings to be satisfied that salvation did not flow through that channel. While he was treated with the utmost liberality by both the government and the people among whom he came to proclaim the doctrines of the Roman Catholic religion, the. converts for his religion were few, if any. But it must be conceded that Rome had well chosen the man who was likely to make converts for popery, if such a thing had been possible. Nicholas was certainly a man of great erudition, and well qualified to gain even the admiration of his opponents. He died November 21, 1634. His works are, Panegyrique de St. Thomizas d 'Aquin (Louvain, 1621, 8vo): — Vie de St. Dominique (Anvers, 1622, 8vo): — Defensio Fidei Ca'thol. (Anvers, 1631,8vo), etc. See Touron, Hommes illustres de l'ordre de St. Dominique; Hoefer, Nouv. Biog. Géneralé 26, 355 sq. (J. H. W.)