Primary Contributors:
Nuno Castel-Branco
Portrait of Nicolaus Steno, c. 1666–75. (Gallerie degli Uffizi, Florence; source of image: Wikimedia Commons)
Nicolaus Steno (1638–1686)
Nicolaus Steno (1638–1686) was the son of a well-positioned goldsmith in Denmark. He studied medicine for three years at the University of Copenhagen before embarking in 1659 on a long journey across Europe. After attending classes at the University of Leiden, from which he received his medical degree in 1664, he travelled to Paris and joined the intellectual circles that soon gave birth to France’s Académie Royale des Sciences. Two years later, in Florence, Steno found the favour of Grand Duke Ferdinand II de’ Medici (1610–1670)—Galileo’s last patron—at whose court he started working as a scientist. Also in Florence he abandoned his Lutheran faith in favour of Catholicism. He became a priest eight years later, in 1675, and then a bishop in 1677. As a bishop, Steno returned to northern Europe, where, among other things, he befriended Gottfried Wilhelm Leibniz (1646–1716) in Hannover. But to Leibniz’s disappointment, Steno’s focus was no longer the study of the natural world. Instead, Bishop Steno was busy tending to minority Catholic communities in Germany. After further travels, he died in 1686 in Schwerin, sixty miles east of Hamburg. At the personal request of Grand Duke Cosimo III de’ Medici (1642–1723), Steno’s body was shipped back to Florence, where it has remained ever since at the Basilica di San Lorenzo. He was beatified by Pope John Paul II in 1988.
Steno’s most famous contribution to the history of science is his theory on the origin of fossils. He argued that by looking at the Earth’s strata it is possible to learn its history, and his ideas are still taught in geology courses as Steno’s laws or principles of stratigraphy. As an anatomist, Steno contributed to a new mechanical understanding of glands; argued against ancients and moderns that the heart was a muscle; renamed the so-called female testicles as ovaries; and developed a mathematical model for muscle motion. Most of these discoveries are still used in modern anatomy and physiology. In anatomy and geology his methods innovated by bringing knowledge and observations from other disciplines—mathematics, mechanics, chemistry—into his work.
Key Bibliographic Source(s)
Nuno Castel-Branco, The Traveling Anatomist: Nicolaus Steno and the Intersection of Disciplines in Early Modern Science (Chicago: University of Chicago Press, 2025), Appendix 2 (<https://press.uchicago.edu/dam/ucp/books/pdf/Castel-Branco_appendices.pdf>)
Contents
This curated catalogue contains all known letters authored by or mentioning Nicolaus Steno from 1659 to the publication of De Solido in 1669. Scientific publications are excluded unless they contain an explicit epistle, such as a dedicatory letter or correspondence directly embedded within the text. Dates reflect local usage as recorded in the primary sources: Protestant regions adhere to the Julian calendar, while Catholic regions follow the Gregorian calendar, which differs by 10 days during this period. Uncertain dates are marked, and uncertain locations are indicated.
For manuscript sources, references cite either the most recent transcription or, where accessible, the original document. The Galileo Collection at the Biblioteca Nazionale Centrale di Firenze (BNCF), which includes correspondence relevant to Steno’s Italian period, is available online (<https://teca.bncf.firenze.sbn.it/manos/browse.jsp?idF=15>). For printed texts, original references are provided, as they are often more accessible than secondary sources (e.g., via Google Books). Non-extant letters are included when their existence is documented in contemporary sources, such as citations in other correspondence.
Further resources
Bibliography
Nuno Castel-Branco, The Traveling Anatomist: Nicolaus Steno and the Intersection of Disciplines in Early Modern Science (Chicago: University of Chicago Press, 2025).
Raphaële Andrault and Mogens Lærke (eds.), Steno and the Philosophers (Leiden: Brill, 2018).
Nicolai Stenonis epistolae et epistolae ad eum datae, ed. Gustav Scherz. 2 vols (Copenhagen: Nyt Nordisk Forlag, 1952).