Blessed Niels Stensen

Blessed Niels Stensen, also known by his Latin name Nicolaus Steno, was a Danish anatomist and geologist, one of the most distinguished naturalists of the seventeenth century. Raised a Lutheran, he embraced the Catholic faith, became a priest, and then a bishop on mission in northern Europe. The Church commemorates him on December 5.

He was born in Copenhagen on January 11, 1638 (January 1 according to the Julian calendar), into a devout Lutheran family. His father was a goldsmith. Niels studied medicine in Copenhagen, Amsterdam, and Leiden. While still a student he discovered the duct of the parotid gland, known to this day as Stensen’s duct. He also showed that the heart is a muscle.

After a stay in Paris he settled in 1666 in Florence under the patronage of Ferdinand II, Grand Duke of Tuscany. There he recognized in fossils the remains of ancient organisms, described how layers of rock are formed, and studied the structure of crystals. His treatise Prodromus of 1669 is one of the works with which geology, paleontology, and crystallography begin.

In Florence his faith was maturing as well. He was shaken by the Corpus Christi procession in Livorno: if the Host is the true Body of Christ, he asked himself, then why does he not honor him as well? His last doubts gave way on All Souls’ Day 1667, and on November 7 he was received into the Catholic Church. From 1672 to 1674 he worked in Copenhagen as royal anatomist, and in 1675 he was ordained a priest in Florence.

In 1677 Pope Innocent XI appointed him vicar apostolic of the Nordic Missions. He was consecrated bishop in Rome by Cardinal Gregorio Barbarigo, now a saint. As titular bishop of Titiopolis he took up residence in Hanover at the court of the Catholic duke John Frederick. From 1680 to 1683 he was auxiliary bishop in Münster, which he left in protest against simony in the election of the new bishop. After two years in Hamburg he moved at the end of 1685 to Schwerin, where as a simple pastor he served a handful of Catholics.

He lived in poverty and austerity, and what he had he gave away to those in need. To Christians of other confessions he showed great charity and tact; John Paul II called him one of the forerunners of the ecumenical movement. He died in Schwerin on December 5, 1686 (November 25 according to the Julian calendar). There was no Catholic priest at his side, so he confessed his sins aloud before those present. His body was first laid in a Lutheran church in Schwerin and later taken to Florence, where it rests in the Basilica of San Lorenzo.

John Paul II declared Niels Stensen blessed on October 23, 1988, in Saint Peter’s Basilica. He said then that Stensen’s whole life had been a tireless search for truth, both scientific and religious. Stensen himself wrote that the things we see are beautiful, more beautiful those we have come to know, and most beautiful of all those we are unable to know.