A New-Old Heaven and Earth: St. Thomas, Kepler, and the Scientific Reception of Copernicus

Christopher Graney

Vatican Observatory

Nicolaus Copernicus proposed that the Earth revolves around the sun.  What did this mean to astronomers of the sixteenth and seventeenth centuries?  What did observations of the heavens and the Earth reveal regarding the nature of the universe and Earth’s place within it, assuming a revolving Earth? Both St. Thomas Aquinas and the great Copernican astronomer Johannes Kepler made what we today might consider a crucial error regarding the starry universe—that is, regarding the heavens.  St. Thomas’s version of this error suggests to us (together with St. Augustine) that major interaction between astronomy and Catholic theology well predated Copernicus; Kepler’s version suggests to us that the Copernican universe that science revealed was not the one usually invoked in our discussions today.  Indeed, the view of a Copernican universe that Kepler (and any good astronomer of his time) was compelled by science to hold shared an important thing in common with the pre-Copernican view of the universe that St. Thomas held.  This commonality cautions us today, both regarding our usual view of the Copernican universe, and regarding the view of the universe towards which science now compels us. 

Christopher Graney is an astronomer and historian of science with the Vatican Observatory who also serves as its public relations officer.  For some years now his research focus has been the history of astronomy, especially the late 16th and early 17th centuries.  That research has resulted in various popular and scholarly articles, and two scholarly books: Setting Aside All Authority: Giovanni Battista Riccioli and the Science Against Copernicus in the Age of Galileo (2015), and Mathematical Disquisitions: The Booklet of Theses Immortalized by Galileo (2017), both published by the University of Notre Dame Press.  In September of this year Paulist Press is scheduled to publish a book by Graney and Vatican Observatory Director Br. Guy Consolmagno: When Science Goes Wrong:The Desire and Search for Truth.