This Day in World History
February 13, 1633
Galileo arrives in Rome for trial before Inquisition
Sixty-nine years old, wracked by sciatica, weary of controversy, Galileo Galilei entered Rome on February 13, 1633. He had been summoned by Pope Urban VIII to an Inquisition investigating his Dialogue Concerning the Two Chief World Systems. The charge was heresy. The cause was Galileo’s support of the Copernican theory that the planets, including Earth, revolved around the sun.
Nicolas Copernicus had published his heliocentric theory in 1543. His ideas were condemned by religious leaders — not only Catholic ones but also Protestants Martin Luther and John Calvin — because they contradicted the Bible. Slowly, though, astronomers began to accept the sun-centered universe.
Galileo’s own acceptance, forged in the 1590s, grew stronger in 1609, when he used a new invention, the telescope, to study the planets. Discovering that the Moon had craters, Jupiter was orbited by moons, and Venus had phases like the Moon, he rejected the accepted belief that the heavens were fixed, perfect, and revolving around Earth.
Church authorities, however, objected to a 1613 letter he wrote supporting the Copernican theory. At a hearing, he was told not to actively promote Copernican ideas. A document placed in the records of the proceeding went further, saying he was ordered never to discuss the theory in any way, but evidence suggests that Galileo’s understanding the document was planted after the meeting by enemies.
By the late 1620s, Galileo believed that Pope Urban would be more open to his ideas than earlier popes. He wrote the Dialogue as a conversation between a Copernican and an adherent of the Church’s geocentric theory, hoping to escape condemnation by presenting both views. The ploy failed, and he was summoned. The panel of cardinals decided to ban his book, force him to abjure Copernican ideas, and sentence him to imprisonment. A few months later, the old man was released to his home, where he lived until 1642.