Brett's Two Cents

Hello everyone! We continue with our brief look at the “Galileo affair.”

After the Inquisition’s decision in 1616 that, though there was not yet enough evidence for the theory of heliocentricism to be taught publicly, it could continue to be privately investigated, Galileo returned home to continue his research. Nine years later (1624), he returned to Rome to meet with Pope Urban VIII, who was a supporter of his work.

Urban presented Galileo with several awards and encouraged the authorities in Tuscany (where Galileo lived) to continue to support his work. Still, Urban also believed that the Copernican theory needed more discussion and scientific observation. It wasn’t yet a proven fact, and shouldn’t be used to answer theological questions.


And here is where human nature enters the story! Galileo, of course, was eager for his work to be publicly endorsed by the Church, even though couldn’t definitely prove heliocentrism. Running out of patience, in 1629 he decided to publish Dialogue Concerning the Two Chief World Systems. The book argued vigorously for the truth of heliocentrism, and thus violated the Inquisition’s ruling that theory could not be taught publicly.

If that’s all that he had done, perhaps he might have gotten away with a slap on the hand. However, in his frustration and pride, he placed a character in the book whom everyone recognized as a thinly-disguised stand-in for Pope Urban VIII, even putting words in this character’s mouth that echoed Urban’s. Worse, he named this character Simplicio, meaning “simpleton”. The Pope was not amused. And in the end, all Galileo was able to prove in the book was that “it is not impossible for the earth to move.”


Hauled once more before the Inquisition, this time without the patronage of the Pope, Galileo admitted he had gone too far in Dialogue and offered to publish an addition to it arguing against the Copernican theory. Eventually, his work was judged “vehemently suspect of heresy.”

His book was placed on the Index of Prohibited Books, and Galileo was required to publicly recant his teaching, which he did. He was sentenced to 3 years in prison, which was immediately commuted. Instead, he lived in limited house arrest, with freedom of movement. He was also required to recite the seven penitential psalms once a week for three years, but was allowed to have his daughter (a Carmelite nun) pray them in his place.

Galileo continued to make scientific observations for the rest of his life and died in 1642, the year of Isaac Newton’s birth.