Blessed Nikolas Steno was not only the father of modern geology, but also a faithful Catholic.
The discovery of 25 million year old shark’s teeth embedded in a hunk of rock on the southern coast of Australia created a sensation in 2015. It was a rare find, because there were several teeth from the same shark, not just one. Discovered by an amateur fossil hunter, it took scientists two years to confirm that the teeth belong to an extinct species of mega-toothed shark, said to be twice the size of a great white.
Interestingly, over 350 years ago, shark’s teeth created a similar sensation and lead to the founding of a new science by Nikolas Steno (1638-1686).
According to a talk at the 2018 Society of Catholic Scientists given by Dr. Andrew Sicree from Penn State University, Steno is credited not only with founding modern geology, he contributed major discoveries in anatomy and is viewed as the founder of 3 other sciences: paleontology, crystallography, and mineralogy.
With such an array of accomplishments one might wonder what forces in his background-people and circumstances-contributed to his enormous success.
Early Years and Education
Born in Copenhagen, Denmark, son of a goldsmith, as a young child he was quite sickly but still managed to study math, logic, philosophy and theology. He was fortunate that his teacher, Ole Borch, at the Lutheran academy frequently put on scientific demonstrations for his students, through which Steno learned the art of observation and experimental design. The friendship between teacher and student lasted Steno’s lifetime.
Upon entering university, he began to study medicine, but the plague interrupted his studies. During this time Borch encouraged Steno to study Descartes, Galileo, Bacon, Gassendi and others. For a short time, his preceptor at the University was none other than Denmark’s leading anatomist, Thomas Bartholin, the first to discover lymphatic vessels. At this time, anatomy was a prestigious science: people would purchase tickets to watch a dissection.
As a student, his first major anatomical discovery was of the parotid duct in a sheep’s head. (Other anatomical discoveries include the follicles of the ovary, the vitelline duct, and the glands that produce earwax.) With the interruption of his medical studies, he was free to pursue his various interests, leading him to travel around Europe (Amsterdam, Paris, and Florence) where he studied and interacted with many of the best scientists of his day. His dissections became famous and were attended by professionals and social elites alike. One witness wrote that he was “the rage” of Paris. He remained there only a year, delivering a lecture on the brain that destroyed the current theories (including Descartes’ claim that the pineal gland was the seat of the soul).
At the age of 28, he was appointed professor of anatomy at the University of Padua and eventually became one of the Medici family’s personal physicians, a position he shared with Francesco Redi, whose famous rotting meat experiment challenged the Aristotelian theory of spontaneous generation.
The Principle of Identity And Shark’s Teeth
Steno used the Aristotelian principle of identity both in anatomy and geology: if two things are alike in every aspect then they must have the same origin. For example, he recognized the muscular nature of the heart comparing it to other muscles in the body.
It was with the dissection of a shark’s head in 1666, while at the Accademia Del Cimento (Academy of Experiment) funded by the Medici family, that this principle came into play again. After dissecting and examining the head of a great white shark, he observed the strict similarity to the glossopetrae found in the mountains and used by many physicians for their “medicinal powers”. He argued that the “tongue stones” brought back from the mountains must be fossilized shark’s teeth, different from the originals in chemical composition. Earlier explanations of their existence claimed they fell from the sky or else, relying on Aristotle’s theory of spontaneous generation, grew from the mountains themselves.
According to Alan Cutler, a geologist himself and author of The Seashell on the Mountaintop, this discovery brought to the forefront of Steno’s mind an unresolved question of the time: Why are seashells often found far from the sea, sometimes embedded in solid rock at the tops of mountains?
The Main Principles of Geology
Both of his previous mentors, Borch and Bartholin, had been interested in and collected fossils, so Steno would have been well aware both of their existence and the various explanations offered for their origins. His travels also would have brought him through many dramatic, rocky landscapes. As an astute observer of the multilayered nature of the human body, he must have seen parallels in the “layers” observable in earth’s surface. As a young student in Borch’s lab, he would have seen stones dissolved in solutions and precipitates coming out of solutions in layers.
In 1669, only a few years after the famous shark head dissection, he published probably his most comprehensive work, Prodromus (or De Solido). It is in this publication that we find the foundational principles of modern geology, which became hotly contested.
- The principle of original horizontality: All layers of rock are deposited horizontally, parallel to the horizon. Later they may be deformed so they form an angle with the horizon.
- The law of superposition: The deeper the rock layer, the older it is: when there are different layers of rock, provided there has been no deformation, the oldest layers are at the bottom and youngest at the top.
- The principle of lateral continuity: Rock layers extend laterally in all directions. Where similar layers of rock are separated, for example by a valley, it can be assumed these rock layers were originally continuous.
- The principle of cross-cutting relationships: Any geologic feature that cuts through another is the younger of the two features.
Conversion to Catholicism
Two years prior to this publication, in 1667, Steno was moved to convert to Catholicism after witnessing a Corpus Christi procession. But that was not enough. In his own words: ‘As soon as I attentively pondered God’s favors to me, these appeared to be so many that I couldn’t help but offer to Him the best of myself and in the best way, from the bottom of my heart… “ After 9 years of studying, in 1675, he was ordained a priest. By 1677, recognizing his zeal to convert his Lutheran brethren, the Pope appointed him bishop after which he went to Hanover to strengthen the Catholics in a heavily Protestant area. He died, exhausted by his efforts and ascetic life-style, at the age of 48.
Blessed Nikolas Steno
In 1988, Bishop Nikolas Steno was declared blessed by John Paul II, a stage on the way to being declared officially a saint. Always pious, even in his youth, Steno’s encounters with the many Catholics, especially in Italy, led him to doubt his Lutheran faith. After his conversion, subsequent ordination, and throughout his ministry as a bishop, he was known both for his asceticism and generosity to the poor. It is said that he sold his bishop’s ring and crozier in order to give the money to those in need.
Some biographers claim that he gave up his scientific interests when he became a priest, but it is known that he was still studying the structure of the brain in 1684, only two years prior to his death.
Steno’s contributions to anatomy and to the new science of geology occurred because he was meticulous in his observations and experimental designs, and was not afraid to challenge long-held beliefs of the “ancients” or new ideas put forth by contemporaries. He had the integrity to admit when he did not know something, a rare virtue in academia of his day and in our own.
Although a scientist at heart, Blessed Steno was also moved by beauty both what is seen and understood, but also what is still beyond our understanding, including the Hidden Beauty beyond our sight.
“Beautiful is what is seen, more beautiful what is understood, most beautiful what is not known.”
Maggie Ciskanik is a regular contributor to the Magis Center blog.