April 12th

The HISTSCI_HULK had just been settling down to the beautiful sunny morning and deciding, which of his Easter eggs he wanted to eat first (chocolate for breakfast on Easter is OK, isn’t it?), when he let out an ear shattering bellow of rage that signalled that he was about to go on the rampage. What could have so upset the valiant defender of truth and accuracy in the history of science? He had been casually perusing the website Today in Science History, a useful calendar of birth, deaths and events in #histSTM, when his eyes were drawn to the following brief statement:


“In 1633, Galileo Galilei’s second trial before the Inquisition began. At its conclusion his belief that the Earth was not the centre of the Universe was pronounced heretical”

What could possible have so enraged the HISTSCI monster in this apparently innocuous historical claim? Well, almost everything. The date and the name are correct but both substantive claims are simply false. Of course, there is the possibility that we have slipped into a parallel universe and are dealing with another Galileo Galilei about whom the stated facts are correct but Ockham’s razor would suggest that the simplest solution is that the facts are wrong.

We start with, “Galileo Galilei’s second trial before the Inquisition began,” Galileo only ever had one trial before the Inquisition so this could not have been the second. This is a wide spread misconception that occurs here not for this first time and it is worth explaining why it’s false. Galileo had to do with the Inquisition three times in his life. Three times, I hear you ask, when or what was the third time. Most people aren’t aware of Galileo’s first run in with the Inquisition, which took place when he was still a relatively unknown professor for mathematics in Padua in 1604.

Galileo was denounced to the Venetian Inquisition by a former amanuensis, Silvestro Pagnoni from Pesaro for practicing deterministic astrology. Yes, Galileo was a practicing astrologer and no, he didn’t just do it for the money. Greek astrology was deterministic, which meant that ones entire life was determined at the point of birth. This conflicted with the Christian belief in free will and was thus considered heretical. Quite why the Medieval Church didn’t just dump astrology is somewhat puzzling but in the thirteenth century Albertus Magnus and Thomas Aquinas redefined astrology, so that it was non-deterministic for human thought. You can read exactly how they did so in Darrel Rutkin’s excellent book, Sapientia Astrologica. Although the Church accepted astrology in the seventeenth century, deterministic astrology was definitely not acceptable. The Venetian Inquisition duly investigated the accusation and, having cleared Galileo of all suspicion, did not pursue the case any further. Galileo’s next brush with the Inquisition was the much more famous one in 1615/16 and it is this one that people mistakenly think was a trial with Galileo as the accused.

What actually happened was that the Church provoked by Galileo’s Letter to Benedetto Castelli and Paolo Antonio Foscarini’s Epistle concerning the Pythagorean and Copernican opinion of the Mobility of the Earth and the stability of the sun and of the new system or constitution of the World set up a commission to investigate and pass judgement on the heliocentric cosmological theory. The conclusion of the commission is generally well known.

The proposition that the Sun is stationary at the centre of the universe is “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture”; the proposition that the Earth moves and is not at the centre of the universe “receives the same judgement in philosophy; and … in regard to theological truth it is at least erroneous in faith.”

Absurd in philosophy can be translated as scientifically false, a correct judgement based on the knowledge of the time, as the available empirical evidence solidly supported a helio-geocentric system and not a heliocentric one.

As Galileo was the leading proponent of a heliocentric world view the Pope, Paul V, instructed Roberto Bellarmino, the Church’s leading theologian to inform Galileo of the commission’s findings and to instruct him that he could no longer hold or teach the heliocentric theory. Bellarmino did as instructed but at no point was Galileo on trail.

The astute reader will have already noticed that it was not at the end of his trial in 1633 that the “belief that the Earth was not the centre of the Universe was pronounced heretical” but already by the commission of investigation in 1616. In fact we now stumble upon a conundrum, the heliocentric theory was never actually officially pronounced heretical. The commission found that the proposition that the Sun is stationary at the centre of the universe is “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture” but only a Pope can formally declare something heretical and no pope ever did.

I’m not going to address the trial itself and the factors leading up to it, as I fairly recently wrote a whole blog post on the topic, which you can read here.

This anniversary provoked an at times heated exchange on Twitter, yesterday and this morning, in which various people attacked the Catholic Church and/or the Inquisition, their attacks based largely on false or inaccurate information and I, as all too often, ended up trying my best to correct their mistaken utterances. I will now repeat some of the core insights from that exchange.

Galileo was during his interrogation and trial by the Roman Inquisition never imprisoned nor tortured and not even shown the instruments of torture, all of which claims are too often believed to represent the truth. He was, in fact, treated with care and respect as an honoured guest throughout his interrogation. He was housed in a luxury apartment with servants to see to his needs and during the breaks between the separate interrogations was even allowed to return to the apartment in Rome where he was staying before the interrogations began. Following the trial where he was found guilty of grave suspicion of heresy, and not heresy as if often falsely claimed, he was sentenced to life imprisonment, which was immediately commuted to house arrest. He spent the first weeks of his house arrest as the honoured guest of Archbishop Piccolomini in his palace in Sienna until it proved too much of a good thing and Urban ordered that he go home. He spent the rest of his house arrest in his own villa in Arceti near Florence, where he was cared for by servants. He was allowed visitors and now too old and too frail to travel anyway he devoted himself to writing the Discorsi, his most important scientific work, which despite a ban was published without the Church undertaking any action against it. The average European peasant in the period certainly lived a much worse life.

One topic that came up several times was that even if not tortured or threatened with torture, Galileo would have been scared of the Inquisition because of its reputation and especially because of what they did to Bruno. If there were a false facts about the Church and Galileo bingo game evoking Bruno would certainly occupy the centre square. These comment stimulated the following speculations on my part:

Actually, I don’t think Galileo was particularly concerned about the Inquisition; his self-opinionated arrogance protected him from such thoughts. He wasn’t a religious nutcase like Bruno, he was the greatest scientist in Europe, he was a Medicean courtier, he was a much admired and feted member of Roman high society, he counted princes and powerful cardinals amongst his best friends and supporters, Maffeo Barberini had been one of his best friends since 1612. When he became Pope Urban VIII, Barberini granted him several private audiences and praised his latest book, Il Saggiatore, it was Barberini who, as Pope, had commissioned him to write his book comparing the geocentric and heliocentric systems, what could he possibly have to fear?

This is of course, as I say, purely speculative but the way Galileo is known to have behaved during his interrogations would seem to support such a view.








Filed under History of Astronomy, Myths of Science, Renaissance Science

12 responses to “April 12th

  1. GG, the gift that keeps on giving…

    • As I’ve said in the past it’s the people who write about GG rather than GG himself

      • Apart from GG, what do you think is the most prevalent popular hist-sci myth? The “middle ages flat earth”? Bruno? 80 epicycles?

        On a related note, Paul Krugman uses the term “zombies” for unkillable misconceptions: “ideas that should have been killed by contrary evidence, but instead keep shambling along, eating people’s brains.”

  2. There is a long list of candidates to choose from and the flat earth is certainly a serious candidate for numero uno. At the moment on social media it’s Newton’s Annus mirabilis, because of the pandemic. I’ve written a post on it, which I’ll be posting on Wednesday.

    I too have used the term zombie for #histSTM myths that refuse to die in an article I wrote for Viewpoints the online journal of the BSHS.

  3. Fundamentally Irrational Belief Systems (FIBS)

  4. How desperately people struggle to maintain their confusion 😜😝😴

    Jonny Cache • April 14, 2017

  5. Pingback: Contro il mito di Galileo [EN] – hookii

  6. Here’s another GG story that should bring out the HISTSCI_HULK

    ‘Galileo was offered a chair at Harvard University, which was founded in 1636, before Charles I had his head cut off. ”

    I came across this in Mark Mills’ blog: https://matteroffactsblog.wordpress.com/2013/09/26/was-galileo-offered-a-chair-at-harvard-university/comment-page-1/
    but it is quoted from John Micklethwait and Adrian Wooldridge’s book on the right in America:

    As journalists at The Economist, i would have expected them to have checked their facts; can any of Thony’s readers from across the pond supply information on where this statement came from?

  7. Ivan

    Bye , bye troll
    Your tone is abusive and insulting but when I take the same tone you fly off the handle and go off in a huff. You are not interested in an engaged debate but only in sneering and pontificating. If you want to tell the world you view of things, then start your own blog; you are no longer welcome here.

    P.S. you will note that I have modified my text in line with the only valid criticism that you brought in all your diatribes

    • Troll

      You made my point about you in a way I never could. Also, you didn’t get my extremely polite suggestion: It is unwise to talk about the scientific status of the heliocentric system with respect to a period where the status of science itself was changing.

      • Also, you didn’t get my extremely polite suggestion

        All of your comments were arrogant and overbearing, were mostly factually incorrect and contained at least one and usually several gratuitous insults. If you wish to communicate with somebody that is definitely not the way to go about it.

        Your last comment is also like many of your previous ones simply bullshit!

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