How Nicolas Steno’s Questioning Mindset Shaped Modern Geology

When thinking about influential people of the past, most of them end up becoming household names. From Aristotle to Leonardo da Vinci, these household names gained popularity throughout the years to allow their names to stay relevant today, along with their discoveries. However, there are a few names that have had their discoveries live one while their names left unknown or forgotten by many – Nicolas Steno is one of them. Steno’s discovery in 1669, involved him rewriting the way in which people thought of the world. His work was crucial to the development and discovery of modern geology.

Steno was born in Florence, Italy, and settled down after years of studying across western Europe. Steno followed his curiosity to wherever it led him while living in an age where scientist did not stick to one discipline. He studied shark dentistry, medicine, and studied ancient beasts. He challenged various long held scientific assumptions “researched the changing shapes of muscles, and discovered an unknown body part in the heads of mammals which he named after himself, the ‘ductus stenonianus’”.

After moving to Florence in 1665, he joined the court of the Grand Duke of Tuscany and got to open a “cabinet of curiosity”, which was essentially a room filled with natural wonders. Steno was able to collect various wonders around the world, and so when a fishermen captured a great white shark in 1666, Steno got to dissect its head. While Steno was “examining the teeth of the shark, he was struck by their resemblance to certain stony objects, called glossopetrae – literally ‘tongue stones’ – that were found in certain rocks,” writes the University of California Museum of Paleontology in its biography of Steno.” Thus “ancient authorities, such as the Roman author Pliny the Elder, had suggested that these stones fell from the sky or from the moon. Others were of the opinion, also going back to ancient times, that fossils naturally grew in the rocks.”

Steno, however, questioned this ideology, he did not understand how a fossil could naturally grow in a rock since a rock is a substance that is completely solid. Steno questioned if perhaps those fossils actually came from animals – which would explain why they’re shaped like parts of animals. These questions seem obvious to us now, but were in fact unusual questions at the time. How could a fossil end up in a rock if it were something that is solid? How could a solid substance, like a rock, wrap around a solid substance, like a tooth? These questions allowed Steno to think outside the box, what if a solid rock was once fluid? And over time it “solidified around and on top of fossils, veins of metal – or even older layers of rock. Since new rock keeps burying and sealing off old rock, then there must be horizontal layers, or strata, throughout the earth.”

This new ideology helped explain the fundamental part of geology which is that “the deeper you dig, the older the stone.” This discovery allowed scientists to understand different time periods by looking at older rocks. It allowed modern geologists to “make conclusions about the past based on the depth of the rock.” However, perhaps the most important thing about Steno’s discoveries was that he demonstrated the importance of not accepting or settling with ideas and the way things are. Steno followed his curiosity and did not dispel of the many questions he had. He instead challenged the accepted ways of thought, and allowed himself to generate new breakthroughs. He ultimately showcased that curiosity can lead to new alternative routes that contain great discoveries.

“Beautiful is what we see, more beautiful is what we know, most beautiful by far is what we don’t.” – Nicolas Steno

Author bio: Idil Dahir

Idil Dahir is a freelance writer and editor living in Toronto, Ontario. She is a recent graduate of the University of Toronto in which she completed a specialist program in English. Idil enjoys everything from Films, TV Shows, Sports, Novels, and Comic Books. She is currently working on her fantasy novel as well as her freelance work. If you would like to contact Idil you can reach her at: