The Galileo Affair

An Italian soap opera in two acts

From the Encyclopedia of Catholicism

“The record of imprisonment, torture, and execution connected with the Inquisition has been a blot on the history of the Church. Its most famous victim was the Italian astronomer and mathematician Galileo.”

Prologue

In 1543 Nicholas Copernicus publishes De Revolutionibus Orbium Coelestium.

A friend (without his permission) adds an introduction in which he says that none of this is to be takes literally. It is merely a “supposition.”

The silence is deafening.

Why was this not taken seriously?

It violated common sense. It threw out 2000 years of coherent

astronomical theory. It violated the laws of physics (as they were

then understood). It predicted stellar parallax (which was too

small to be seen). It contradicted some passages in scripture.

Act I – Enter Galileo

Galileo (1564 – 1642) becomes convinced that Copernicus was right, and discusses this with some friends. In particular, he writes a letter to Fr. Benedetto Castelli explaining his views. This letter will become important later on.

He claims that the Bible must be interpreted in the light of modern scientific findings and that it was written in a language that was “accommodated” to the people for whom it was written.

Famous quote:

Cesare Cardinal Baronio: “The Bible tells us how to go to heaven, not how the heavens go.”

First Signs of Trouble

December 1614 a minor cleric named Tommaso Caccini preaches a sermon at Santa Maria Novella in Florence denouncing Galileo and his followers.

February 1614 another cleric from the same city Niccolo Lorini wrote a letter to the inquisition together with a copy of Galileo’s letter to Castelli which had been partly altered to make Galileo look bad.

The Inquisition

Originally (13th century) traveling tribunals intended to root out and punish heretics.

The Roman Inquisition established in 1542 as part of the Church’s response to the Protestant reformation.

It was the final tribunal of the Church dealing with matters of heresy.

March 1615 – The Inquisition summons Caccini who makes all manner of wild accusations which turn out to be rumors from Lorini.

The Inquisition is still worried about heliocentrism and outsources the matter to a panel of experts.

February, 1616: The panel returns a damning report – Copernicanism is “foolish and absurd” in philosophy and heretical in theology.

Copernicus’ book is placed on the Index of forbidden books to be “suspended until corrected.”

Index of Forbidden Books

Books Catholics were forbidden to read at pain of excommunication

Established in 1557. Abolished by Pope Paul VI in 1966.

February 1616: Cardinal Roberto Bellarmino was told to meet with Galileo and inform him of the decree of the Index and to advise him to abandon his claim that Copernicanism was literally true.

What exactly happened? We don’t know.

More about Bellarmino

A Neopolitan priest Paolo Antonio Foscarini wrote a book interpreting Biblical texts in such as way as to make them compatible with Copernicanism. He sent a copy to Bellarmino .

Bellarmino’s Reply

There is no danger in saying that by assuming the earth moves and the sun stands still, one saves all the appearances better than by postulating eccentrics and epicycles, that is sufficient for the mathematician. However, it is different to want to affirm that in reality, the sun is at the center of the world and the earth revolves with great speed around it. This is a very dangerous thing, likely not only to irritate all scholastic philosophers and theologians, but also to harm the holy faith by rendering Holy Scripture false.

Belarmino’s further claim

Furthermore – if there were an undeniable proof of the motion of the earth then scripture would have to be reinterpreted carefully.

Biblical interpretation is a key issue. But who is to do the interpreting? Why has this suddenly become important?

Why all the Fuss?

The protestant Reformation began 1517. Council of Trent 1545 – 1563 Forbade the reinterpretation of Scripture in

ways “contrary to the consensus of the church fathers.”

There was a paranoid concern with non-standard Biblical interpretations.

Undeniable proof?

The phases of Venus Satellites of Jupiter The tides are caused by the motion of the

earth.

What happened next?

March 1616: Galileo went to see the Pope. He was warmly welcomed.

The Pope reassured Galileo that he was safe from his enemies, “so long as I live.”

Bellarmino and the Mysterious Certificate

Bellarmino gives Galileo a certificate saying that he had not been condemned or censored in any way but he should not hold or defend Copernicanism.

Act II – Seven Years Later

Galileo’s old friend Maffeo Barberini was elected Pope Urban VIII in August 1623.

Galileo visited the Pope in April 1624 and was treated warmly.

The Pope’s Instructions

It is OK to write about Copernicanism provided: It is presented as a hypothesis. That he include the argument that because God

is omnipotent we can never be certain about ultimate causes.

Galileo returns to Florence and begins work on his new book provisionally called “On the Tides” was finished in 1630.

He wants to publish in Rome with the Lyncean Academy, the first international scientific society headed by his friend Prince Frederico Cesi.

Publication

May 1630 – Submitted “On the Tides” for review to the Vatican Secretary and chief censor for Rome, Niccolo Riccardi. The book is approved pending a few changes and a final review.

Trouble

August 1630 – Cesi died; the Lyncean Academy collapsed.

The plague broke out so Galileo couldn’t send the book to Rome.

March 1631 – Galileo moved to have the book published in Florence. Eventually Riccardi sent along approval and list of items to be addressed.

Climax

The book now called “A Dialogue on the Two Chief World Systems” is published in 1632.

The Pope is furious. “I have been deceived.”

Why is the Pope Mad?

Galileo neglected to tell him about Cardinal Bellarmino’s instructions that he not defend Copernicanism.

The Pope’s argument about ultimate causes was put in the mouth of Simplicius, a blithering idiot.

The Pope is already under attack for his handling of the 30-years war. This is the last thing he needs!

More about the 30-years war

Catholic Powers – the Holy Roman Emperor and the King of Spain (the Hapsburg empire)

Protestant Forces – The German states and Sweden financed by France

Spain rallied against the Pope insisting that he help the cause.

Galileo and the Inquisition

October 1632: Galileo is summoned for questioning.

Galileo shows the Inquisition his certificate from Bellarmino. They have a copy in their files but it is substantially different and is unsigned. (Bellarmino by this time was dead.)

They offer Galileo a “plea bargain,” but the Pope will have none of it.

June 21, 1633: Galileo is arrested and formally interrogated.

Epilogue

He is convicted of “vehement suspicion of heresy” and forced to a humiliating recantation.

Galileo is placed under house arrest in his villa at Arcetri outside of Florence where he dies in 1642, the year Isaac Newton was born.

Some Philosophical Concepts

Instrumentalism: Scientific theories are simply useful tools for “saving the phenomena.”

Realism: Scientific theories are true depictions of the world. Scientific ideas really do describe the world as it objectively is.