Paul M. Krueger

Galileo Galilei is formally banned by the Roman Catholic Church from teaching or defending the view that the earth orbits the sun.

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ㅤOn February 19, 1616, the Inquisition’s investigation into Galileo’s advocacy of heliocentrism intensified, as a commission of theologians, the Qualifiers, were asked to evaluate the propositions of the Copernican view. This referral stemmed from prior depositions, notably that of Gianozzi Attavanti, which confirmed Galileo’s support for a stationary Sun and mobile Earth. It’s also speculated that Galileo’s own efforts to prevent the condemnation of Copernicanism may have hastened the Qualifiers’ involvement. By February 24, they delivered their unanimous report, deeming the concept of a stationary Sun “foolish and absurd in philosophy, and formally heretical,” and the Earth’s motion “at least erroneous in faith.” The following day, Pope Paul V instructed Cardinal Bellarmine to inform Galileo of this judgment and order him to abandon his Copernican beliefs, with the threat of further action if he resisted. Consequently, on February 26, Galileo was ordered to “abstain completely from teaching or defending” heliocentrism.

ㅤFollowing this judgment, the Church took further steps to suppress Copernican ideas. The papal Master of the Sacred Palace banned Foscarini’s “Letter,” and Copernicus’ “De revolutionibus” was suspended. The Congregation of the Index, with papal approval, went further, banning all books promoting the Copernican system, labeling it “the false Pythagorean doctrine, altogether contrary to Holy Scripture.” While a corrected version of “De revolutionibus” was later permitted, the original remained banned until 1758. Galileo’s own works advocating Copernicanism were also prohibited, and his sentence explicitly forbade him from “teaching, defending… or discussing” the theory. Similarly, Kepler’s works were banned in Germany by papal order.