With Due Respect: The Church persecuted Galileo for his scientific views!

Tower of Pisa, Italy 2009

Galileo, the man, the myth
Galileo Galilei (1564-1642) is often portrayed as a man ahead of his time. After all, he was a brilliant astronomer and mathematician. Appointed to the chair of the University of Pisa in 1589, he was spent the next twenty years making groundbreaking scientific discoveries.

The story of the man himself is often used as an example of how Christianity inhibits scientific discoveries. Galileo is shown as a man who was the first to show that objects of differing weights fall at the same speed, disgraced Aristotle's theories, proved Copernicus's ideas (of heliocentrism; the idea that the earth moved around the stationary sun) right, and ultimate irked the Roman Catholic Church with his findings so much that they finally persecuted him. A fascinating tale-- too bad none of it is true (Hannam, 2011).

Wait, what?
First of all, the idea of falling bodies moving at the same speed was already being championed by the scientific community at that time, as part of the project to show that the Greek philosopher Aristotle was wrong among many things. Secondly, Copernicus's ideas had already been proven by Johannes Kepler. And lastly, the Roman Catholic Church placed Galileo under house arrest for political reasons, rather than scientific or theological reasons. For the purpose of this post, I will be focusing on the apparent conflict between Galileo and the Roman Catholic Church. (Hannam, 2011)

Welcome to the 17th century
During the early 1600s, the prevailing view of astronomy were that of Aristotle's. The heavens (which could neither be generated nor decayed) were moving in concentric circles, with earth at the centre.

In 1609, Galileo was making astronomical observations using a brand new scientific equipment-- the telescope. After noticing more stars in the universe than previously thought, he observed sunspots and lunar craters. This suggested that the heavens were not unchangeable and perfect circles as Aristotle thought. More importantly, he noted that the planet Venus had different shapes at different times-- sometimes a complete disk, sometimes a semi-circle, and sometimes even barely visible. This made him conclude that Venus did not revolve around Earth; it revolved around the Sun.

The die-hard Aristotelian professors were eager to reject Galileo findings in advance. His colleague, Giulio Libri (c.1550-1610), Professor of Aristotelian Philosophy at the University of Pisa had trouble seeing through the telescope, and when he died, Galileo remarked that he could probably see the moons of Jupiter "on the way to heaven". This statement suggested how Galileo treated his opponents publicly, and it was no surprise that Galileo had few friends later in his life.

Ironically, it was the Jesuits (the Roman Catholic order of monks dedicated to education) who first warmly received Galileo's findings. The Jesuit Christopher Clavius (1538-1612), the most respected astronomer at that time confirmed his discoveries, and planned to set about ideas to reform astronomy (Lattis, 1994). The problem for Galileo now was that even though his observations contradicted the Aristotelian model of astronomy, he could not prove Copernicus's.

You mean there is another model?
Years earlier, another astronomer named Tycho Brahe (1546-1601) proposed his system of astronomy-- the earth was stationary, the Sun went around the earth, and everything else moved around the sun. After Galileo presented his work in 1611, Tycho's model became the preferred one over Aristotle's, and Copernicus's.

Furthermore, Copernicus's model was already in a bad light--Cardinal Roberto Bellarmino (1542-1621), the 'Consultor of the Holy Office and Master of Controversial Questions', was unconvinced that the Copernicus model was true (as it had yet to be demonstrated) and an Italian theologian Paolo Foscarini (1565-1616) had been aggressively advocating the Copernicus model. Thus in 1616, Copernicus's Revolution of the Heavenly Spheres was suspended from public till it's correction (Hannam, 2011).

Vatican City, 2009

Friends in high places
In 1623, Galileo's good friend, Cardinal Maffeo Barberini (1568-1644) ascended the papacy to become Pope Urban VIII. Earlier that, Galileo published Il Saggiatore ('The Assayer'), mocking Jesuit Orazio Grassi(1583-1664)'s theories about comets. Grassi had argued that comets were further from the earth than the moon, while Galileo insisted that comets were an atmospheric illusion. (Incidentally, modern science concurs with Grassi.) Pope Urban VIII enjoyed the Il Saggiatore, and composed a poem in Galileo's honour.

Taking advantage of his new-found favour with the Catholic Church, Galileo travelled to Rome in 1624 to meet with the pope to explain his advocacy of the Copernicus model. Despite meeting Galileo no less than six times, Pope Urban VIII remained unconvinced. While he did not consider the Copernicus model heretical, he was unsure if it was correct either. He encouraged Galileo to treat the Copernicus's ideas as a hypothesis, rather than a fact, and asked Galileo to publish a book comparing the three models of astronomy (Aristotelian, Tycho and Copernicus). Pope Urban VIII was actually asking Galileo to be more open-minded in this case (Hannam, 2011)

But Galileo took the pope's kindness for granted
So in 1632, Galileo wrote Dialogue Concerning The Two Chief World Systems. In it, he portrays the astronomical debates as a discussion between an academic named Salviati (who represented Galileo), a Aristotelian simpleton named Simplicio and a biased chairman named Sagredo (who always agrees with Galileo's views).

When Pope Urban VIII read the book, he was furious. Some of the pope's doubts and arguments against Copernicus's models were placed in the mouth of Simplicio. Furthermore, Galileo's book omitted Tycho's model entirely, even though Galileo's "evidences" for Copernicus's model could also be applied to Tycho's (Finocchiaro, 1989)*.

And Galileo's punishment? He was NOT burnt, tortured or even flogged. Despite his soured relations with the pope, Jesuits and academia, he was placed under house arrest, and lived in comfort till his death in 1642.

Conclusion
So in the life of Galileo we learnt that
a) Despite Galileo being right about Copernicus's models, he did not prove it scientifically or observationally, although he showed it to be superior to Aristotle's (but not Tycho's).

b) The Roman Catholic Church did not go after Galileo because his findings were a threat to Christianity, but because he was extremely rude to his colleagues and superiors. He was persecuted for personal (and perhaps political reasons).

c) Although this example often crops up a science vs Christianity case study, it is a misrepresentation of issue.

Let me be clear-- Galileo was a great scientist and presenter. He was able to write fluently and present his scientific ideas as a coherent whole. However, his attitude got the better of him.

References
Finocchiaro, M.A. (1989) The Galileo Affair

Lattis, J.M. (1994) Between Copernicus and Galileo

Hannam, J. (2011) God's Philosophers

Further reading
Bethinking

*Galileo's evidences for a rotating earth mainly included the existence of tides in the waters. He argued that tides exist because of the inertia experienced by the waters as the earth moved. However, it was not convincing at that era because if he was right, we would been experiencing great winds all the time. Now we know tides are caused by the moon's gravitational effect on the waters (Hannam, 2011).