STENSEN, NIELS, BL.

Also known as Nikolaus or Nils Steensen, Steno, Stens, or Stenonis; pioneer in the field of anatomy, founder of scientific paleontology, geology, and crystallography, bishop; b. January 11, 1638, Copenhagen, Denmark;d. December 5, 1686, Schwerin, Germany.

His parents were Lutheran; his father, a goldsmith, was the descendent of a long line of Lutheran pastors in Scania. At an early age Niels showed a strong interest in mathematics and science, and he began to study medicine in 1656 at the University of Copenhagen. His first discovery (1660) in Amsterdam was the excretory duct of the parotid gland (Steno's duct); it was followed by many more discoveries after he moved to Leiden (July 27, 1660). These are described in the Observationes anatomicae (Leiden 1662) and Observationum anatomicarum specimen (Copenhagen 1664).

After the University of Copenhagen passed him over, the University in Leyden granted him the degree of doctor of medicine in absentia in 1664. In Paris (1665), in the house of M. Thévenot, he delivered his Discours sur l'anatomie du cerveau (Paris 1669) to the forerunners of the Académie des Sciences. There he gained a reputation as an embryologist and brain anatomist. The following year he was well received at the court of the Medici, and among the members of the Accademia del Cimento, which had been founded in the spirit of Galileo; he resumed anatomical research at the Ospidale de S. Maria Nuova in Florence. By sectioning the head of a large shark and by stating the organic origin of the glossopetrae (fossilized shark teeth) he was led to basic discoveries in the fields of paleontology and geology. These discoveries he published succinctly and hurriedly in the Elementorum myologiae specimen seu musculi descriptio geometrica (Florence 1667) and Prodromus de solido intra solidum naturaliter contento (Florence 1669).

While residing in the Netherlands he had begun to question Lutheran doctrines. A Corpus Christi procession in Livorno, Italy deeply impressed him and he decided to become a Catholic; and on November 7, 1667 he entered the Church. Shortly after, he received a letter from the crown of Denmark calling him home and offering him a high annual salary. But it was too late; he did not feel that he could return to Denmark as a Catholic.

After a journey covering half of Europe in 1669 and 1670, he returned to Italy for a time, then served as royal anatomist in Copenhagen from 1672 to 1674. Discerning a call to the priesthood, he went back to Italy and was ordained in Florence before Easter 1675. He was appointed tutor of the crown prince of Florence, but upon request of Duke Johann Friedrich of Hanover, Innocent XI made him vicar apostolic for the Nordic Missions on August 21, 1677, and he was consecrated bishop of Titiopolis on September 19. His territory extended to the north of Norway, but it contained very few Catholics. In his dealings with Protestants in Hanover he showed both determination and mildness (e.g., his discussions with G. W. Leibniz).

After Johann Friedrich's death, Prince-Bishop Ferdinand von Fürstenberg of Paderborn requested Stensen as auxiliary bishop of Münster (appointed October 7, 1680). With great zeal he continued the work of reform begun by C. B. von Galen. His vibrant preaching led many back to Catholicism. In his Parochorum hoc age (Florence 1684) he exhorted both clergy and laity to follow the example of the early Church. In 1683 he left Münster in protest against a simoniacal election. After two years of strenuous activity in Hamburg, he spent the last year of his life as a missionary in Schwerin.

Stensen ranks with the most eminent scientists. Among other things, he discovered many glands and glandular ducts in the eye, mouth, nose, skin, chest, and the mucous canal system of fish. He described the structure in general and in particular muscles such as those of the tongue and esophagus. He pioneered in declaring the heart to be a muscle and in stating the function of the uterus and ovaries, and in new methods of research on the brain. His chief contributions were his scientific explanations of fossils, geological stratification, the development of mountains, the difference between organic and inorganic growth, and the law of the constancy of crystalline angles.

Stensen became a model for all times through his desire for certitude, combining, happily, the most exacting inductive method with ingenious deductive conclusions. Though enthusiastic about mechanical and mathematical methods, he contradicted Descartes from the biological point of view, and referred Spinoza, the friend of his youth, to the philosophia perennis in his Epistola ad novae philosophiae reformatorem de vera philosophia. His coat of arms reflect his ideals (a heart crowned with a cross), and his most quoted saying is: "Pulchra quae videntur, pulchriora quae sciuntur, longe pulcherrima quae ignorantur" ("Beautiful are the things that are seen; more beautiful are the things that are known; and most beautiful of all are the things that are not known").

As priest and bishop, Stensen was a reformer. He became most influential through his own personal striving for sanctification in poverty, strict asceticism, and a deep union with God. Of his 16 theological works the more interesting are his Epistola de propria conversione (Florence 1677) and Defensio et plenior elucidatio epistolae de propria conversione (Hanover 1680).

His nine years of difficult labor in northern Germany eroded his health. When he died at age 48, he was venerated as a saint in the diocese of Hildesheim. After his death, Cosimo III had his remains transferred to the crypt of St. Lorenzo in Florence, from where they were solemnly removed to a chapel in the transept of this basilica in 1953. His canonization process was begun in Osnabrück in 1938. Pope John Paul II beatified him October 23, 1988.

Feast: December 5.

Bibliography: Works. Opera philosophica, ed. v. maar, 2 v. (Copenhagen 1910); Opera theologica, ed. k. larsen and g. scherz, 2v. 2d ed. (Copenhagen 1944–47); Epistolae, ed. g. scherz, 2 v. (Copenhagen 1952); The Prodromus, tr. and ed. j. w. winter (New York 1916); The Earliest Geological Treatise, tr. c. carchariae, ed. a. garboe (New York 1958); Chaos-manuscript, Copenhagen, 1659, ed. a. ziggelaar (Copenhagen 1997). Studies about Stensen: r. angeli, Niels Stensen anatomico, fondatore della geologia, servo di Dio (Florence 1968). m. bierbaum, Niels Stensen: Anatom, Geologe u. Bischof, 2d ed. (Münster 1979). r. cioni, Niels Stensen: Scientist-Bishop, tr. g. m. camera (New York 1962). a. garboe, Nicolaus Steno and Erasmus Bartholinus (Copenhagen 1954). u. heida, Niels Stensen und seine Fachkollegenin (Berlin 1986). a. d. jÖrgensen, Niels Stensen, ed. g. scherz, 2d ed. (Copenhagen 1958). t. kardel, Steno: Life, Science, Philosophy (Copenhagen 1994); tr., Steno on Muscles (Philadelphia 1994). v. maar, To uudgivne Arbejder af Nicolaus Steno fra Biblioteca Laurentiana (Copenhagen 1910). j. metzler, Die Apostolischen Vikariate des Nordens (Paderborn 1919). h. moe, Nicolaus Steno: An Illustrated Biography, tr. d. stoner (Copenhagen 1994). e. k. pa ° lsson, Niels Stensen, Scientist and Saint, tr. m. n. l. couve de murville (Dublin 1988). w. plenkers, Der Däne Niels Stensen (Freiburg 1884). k. j. plovgaard, Niels Stensen: Anatom, Geologog Biskop (Copenhagen 1953). n. quattrin, Nicola Stenone scienziato e santo (1638–1686) (Vicenza 1987). s. de rosa, Niccolò Stenone a Volterra, 1668, tr. g. lazzeri (Florence 1996). g. scherz, Dansk biografisk leksikon, ed. c. f. bricka et al., v.22 (Copenhagen 1942); Vom Wege Niels Stensens (Copenhagen 1956); N. Steno and His Indice (Copenhagen 1958), with biography and essays on his scientific work; Niels Stensen (Würzburg 1962); Pionier der Wissenschaft (Copenhagen 1963), list of sources; Niels Stensen: Forscher und Denker im Barock (Stuttgart 1964); Niels Stensen: The Goldsmith's Son from Copenhagen …, tr. r. spink (Copenhagen 1988).

[g. scherz]