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Galileo and the trial of 1633
1610–1633· Event· Knowledge, logic & science
Well documentedSolid records, texts or physical evidence.
Galileo's telescope discoveries supported Copernicus, and in 1633 the Roman Inquisition forced him to recant and confined him for life.
See it on the Philosophy map →The idea
From 1610 Galileo's telescope revealed mountains on the Moon, four moons circling Jupiter and the phases of Venus, which fit a Sun-centered system. In 1616 the Church ruled heliocentrism contrary to scripture and warned him. His 1632 Dialogue argued for it anyway and seemed to mock Pope Urban VIII. In 1633 the Inquisition found him 'vehemently suspect of heresy'; he recanted and lived his last nine years under house arrest. His critics had a point: he lacked decisive proof, and his tides argument was wrong.
Why it matters
It became the iconic clash between science and religious authority, pushed scientific work toward Protestant northern Europe, and frightened Descartes into withholding his own physics.
Where it comes from
The Starry Messenger, the Dialogue, the 1633 sentence and his signed recantation survive; the Vatican opened its files to scholars, and in 1992 Pope John Paul II acknowledged the Church erred.
Still debated
'And yet it moves' is almost certainly legend, first printed in 1757. Historians debate how much the trial turned on science versus papal politics and personal offense.
Connections (2)
▸Copernicus, On the Revolutions of the Heavenly Spheres was defended, at great cost, in Galileo and the trial of 1633Well documented
The connection
Galileo became Copernicus's most famous champion. His telescope findings, especially the phases of Venus, broke the old Earth-centered system, and his Dialogue (1632) argued that Earth moves. Because the Church had suspended Copernicus's book in 1616 'until corrected', defending it as physical truth led directly to Galileo's trial.
When and how
Padua, Florence and Rome, 1597–1633; in 1597 Galileo privately told Kepler he had long been a Copernican.
How we know
Galileo's 1597 letter to Kepler, the Starry Messenger and Dialogue, the 1616 decree and the 1633 sentence, which names the Copernican doctrine, all survive.
Debates and open questions
Why Galileo ignored Kepler's elliptical orbits, which made Copernicus work far better, is debated; Tycho Brahe's hybrid model also fit Galileo's observations.
▸Galileo and the trial of 1633 frightened René DescartesWell documented
The connection
In 1633 the Roman Inquisition condemned Galileo for teaching that the Earth moves. Descartes, about to publish The World, which also had the Earth move, withdrew it at once. He later published his physics cautiously, and The World appeared only after his death.
When and how
Galileo was condemned in Rome in June 1633; Descartes, living in the Dutch Republic, heard the news that November.
How we know
Descartes' November 1633 letter to Mersenne says he almost burned his papers on hearing of Galileo's condemnation; The World was finally published in 1664.
Debates and open questions
How much fear, versus a wish to avoid controversy and stay in the Church's good graces, drove his caution is debated.