The 17th century science-religion relationship is by all means one of the most intriguing topics of the history of modern culture, which not by chance has been receiving increasing attention from the science, theology and culture historians. Though undoubtedly representing a key-figure in the modern history of science, unaccountably few if any studies have been hitherto devoted to a thorough illustration of the science-faith relationship in the life and works of the Dane Nicho-las Steno (1638-1686), one of the greatest anatomists of his century, founder of geology and crystallography, who, once in Tuscany, recanted his previous Lutheran faith for Catholicism, took the Holy Orders and was finally beatified by Pope John Paul II. Close friend of Viviani, Redi and Magalotti, in contrast with Borelli, he was fully inserted in the Galilean heritage of the Cimento Academy. Yet, unlike Galileo, he never was at odds with the religious hierarchies, nor did he perceive any substantial clash between his philosophy and his theology. Renewed inquiries made in the Floren-tine libraries and archives, as well as in Steno’s published texts, show how relevant, both scientifically and religiously, was his relationship with the Medici family and Cosimo III in particular. Endowed with a deeply Christian conscience, this «spiritual son of Florence» (as he considered himself) tried to conciliate science and faith through a life path that, even if not always consistent, by all means remains an emblem of the Scientific Revolution.
