'Qualis alio modo reperiri non potest' : a few words on Copernican necessity

I will examine what counts as necessary in the Copernican world, primarily as presented in Book I of De revolutionibus orbium coelestium (1543). In doing so, I will consider how Copernicus offers his system as an idea mundi, such that the intellectual vision of the astronomer converges with the divine vision of necessity. My reading here owes a particular debt to Georg Joachim Rheticus (1514–1574) and Johannes Kepler (1571–1630) and to the astronomical frontispieces of Oronce Fine (1494–1555). I also ask what necessities Copernican astronomy imposes on material bodies. I argue that Copernicus presents matter as perfect—perfectly incarnating geometry—at the cosmographical-astronomical scale. Material contingency, for him, arises only at smaller scales. My analysis of these issues extends to numerous points within Copernicus’s context and within the sixteenth-century reception of his work.