Fergie's Tech Blog

22 June 1633: Galileo Forced to Recant Heliocentric Theory

Pope Urban VIII personally asked Galileo to give arguments for and against heliocentrism in the book, and to be careful not to advocate heliocentrism. He made another request, that his own views on the matter be included in Galileo's book. Only the latter of those requests was fulfilled by Galileo. Whether unknowingly or deliberate, Simplicius, the defender of the Aristotelian Geocentric view in Dialogue Concerning the Two Chief World Systems, was often caught in his own errors and sometimes came across as a fool.

This fact made Dialogue Concerning the Two Chief World Systems appear as an advocacy book; an attack on Aristotelian geocentrism and defense of the Copernican theory. To add insult to injury, Galileo put the words of Pope Urban VIII into the mouth of Simplicius. Most historians agree Galileo did not act out of malice and felt blindsided by the reaction to his book. However, the Pope did not take the public ridicule lightly, nor the blatant bias. Galileo had alienated one of his biggest and most powerful supporters, the Pope, and was called to Rome to explain himself.

With the loss of many of his defenders in Rome because of Dialogue Concerning the Two Chief World Systems, Galileo was ordered to stand trial on suspicion of heresy in 1633. The sentence of the Inquisition was in three essential parts:

• Galileo was required to recant his heliocentric ideas, which were condemned as "formally heretical".
• He was ordered imprisoned; the sentence was later commuted to house arrest.
• His offending Dialogue was banned; and in an action not announced at the trial, publication of any of his works was forbidden, including any he might write in the future.

In modern terms, we consider Galileo's views on heliocentricity to be no fundamental advance. The Sun is no more the center of the universe than the Earth is (indeed, the question has no meaning, as apparently all locations can be equally regarded as the "center" of the universe).

The Catholic Church held to the prevailing scientific opinion of the day, which was that the Earth was the center of the universe. Thus, for moderns, the key issue of this controversy was not the objective correctness of the theories being debated, but rather the morality of institutions (or persons) using brute force to shape acceptance of scientific beliefs.

posted by Fergie @ 6/21/2006 10:01:00 PM