Hello, and welcome to Western CIV. Episode two hundred and seventy three Galileo,
Part five. We've talked a lot about Galileo and his role in modernizing
science in the West. Galleo probably would not have qualified as an experimental scientist
in our sense of the term, but certainly he was the first real experimental
scientist in the West if we compare him to everyone who came before him.
It is the break with the past that matters with Galileo, and when talking
about Galileo, that break is huge. Today we get more into the nuts
and bolts of why we all know the name Galileo. Today we start to
look at Galileo and Copernicanism and how his publications drew the ire of the church,
and how that conflict shaped the future of science in so many ways.
Between sixteen eleven and sixteen thirteen, Galileo attempted the impossible. He wanted to
try to bring science and religion together. Today many churches do this and do
this very effectively. Many denominations don't take the Bible literally. They see sciences
explaining the how how did God create? Not the why. The why remains
the realm of the mystical. But in the seventeenth century this division just wasn't
a thing. It was assumed that science should be firmly subordinated to script Scripture,
which was to be read literally. From sixteen thirteen to the end of
his life, Galileo would try to separate religion and science, but that doesn't
mean that we should ignore the preceding two years when he really tried to become
the world's foremost Catholic scientist. To understand this strategy, it's crucial to understand
that Galleo's adversaries were not at this point the entirety of the Church. Really,
his only enemies were ardent Aristotelians believed that these men were nothing more than
slaves. Blindly following everything Aristotle wrote, Aristotelians only looked at the paper world
constructed by Aristotle and they assumed it was true, completely ignoring the supreme level
of contradiction with the real world that they were experiencing. Every educated person knew
that Aristotle was not easy to reconcile with Christianity. According to the most reputable
authorities, Aristotle regarded the universe as having always existed. In other words,
this denied creationism. He denied the immorality of the soul, and he left
no conceptual space for miracles. Galeo would have been a well aware of the
deep suspicion with which the Church regarded the teaching of strict Aristotelian philosophers. It
was thus natural for any opponent of Aristotelian philosophy to wonder if an alternate philosophy
might be easier to reconcile with Christianity. Galileo not only thought about this,
but also took advice, and the advice was that he should emphasize the creation
of the world and the mutability of the heavens. Both of these were denied
by Aristotle but asserted by the scriptures. Thus Galileo was not only interested in
forming a close alliance with the Jesuits, in building ties with such key cardinals
as Mifeo Babini and with prominent pious layman also publishing in Rome. He was
also committed to claiming that the new astronomy was also more Christian than the old
astronomy. That Agossi produced a substantial theological argument to this effect, one that
he hoped would be published alongside Galileo's letters on Sunspots and the Letters on Sunspots
contained an important passage where Galileo insisted that the sun spots demonstrated against Aristotle that
the heavens were mutable, and that this corresponded with the teaching of Holy Scripture.
When the text was submitted to the censors, however, this was one
of three passages that were struck out. The censors adamantly refused to allow any
theological discussion in the Book on Sunspots and insisted that the question about whether the
Bible was compatible with Aristotelian teaching on the immutability of the heavens was far from
straightforward, and in any case it was a matter for theologians, not mathematicians.
Galleo tried repeatedly to retain his core argument while revising his text, but
no compromise could be reached. This was, in a sense lucky for Galleo.
It meant that later when he claimed that he was interested only in discussing
science, not religion, there was no obvious evidence to contradict him, and
the result is that the logic of his activities in these years became invisible to
the modern reader. Now, Galileo was full of confidence as he sat down
to write his work on sun spots in May of sixteen twelve, And why
shouldn't dp He had proof that sun spots were real. The sun did change.
The proof was right there, you could see it. Hence Aristotle's position
that the heavens didn't change was wrong. All you had to do was look,
and you'd be forced to agree. Galileo truly believed in the summer fall
and early winter of sixteen twelve that this was it. This was the end
of the line for Aristotelian logic. His letter on sun spots would prove to
be its death blow. With hindsight, we know that Galileo badly misjudged the
situation. Sixteen twelve would prove to be the high point of his relationship with
the Church, would be all downhill from here, But of course Galileo did
not know that in sixteen twelve. By December of sixteen twelve, Galileo had
virtually completed his career as a practicing scientist. Every important discovery that he was
going to make he had now made, and one great discovery had slipped through
his grasp. He had noticed one night that once a small star seemed to
be further from its nearest neighbor than it had been the night before. What
he had actually seen, though, was a new planet, Neptune, a
planet which was not properly discovered until eighteen forty six. But the idea of
a new planet had not occurred to Galileo, so he did not linger over
this abnormality. He continued to work on tables of Jupiter's moons, but otherwise
he stopped exploring the heavens. In his discourse on Floating Bodies, he had
published a major illustration of the experimental method. He went on experimenting now and
again that all of his important experiments were in the past. He was about
to turn forty nine years old, and he already had a sense of himself
as being old and of time being short. What he needed to do now
was publish the work he already had in hand. But this was not to
prove straightforward. Of course, everything that happens from sixteen thirteen onward depends not
necessarily on Galileo but on Copernicus. The first indication that Galileo's position might be
deteriorating, rather than improving, came in the morning of the twelfth of December
sixteen thirteen, Benedito Castilli had breakfast with the Grand Duke, the Duchess,
and the Grand Duke's mother, Christina of Lorraine, who were on one of
their periodic visits to Pisa. Also present, amongst others was a piece an
Aristotelian philosopher Cosmo Bascali. Castili, as one might expect, had spoken up
in praise of Galileo's latest scientific discoveries. Buscallo had conceded that galiles those telescopic
discoveries were indeed to be trusted, but he rejected the idea of a moving
Earth, which he said was contrary to scripture. Castilli finished his meal and
left, but just as he had emerged from the palace, porter came chasing
after him to summon him back to Christina's room. There he found the group
from breakfast had gathered, and Christina had set about to prove that Copernicanism was
contrary to the Bible. Castilian reply defended Copernicanism and had the support of everyone
present apart from Christina and Bascalini. Galileo, having received a detail account of
the discussion from the two sources, wrote a letter back to Castilli on the
twenty first of December, copies of which were soon in circulation. Now there
was nothing particularly alarming about the debate in the Ducal Palace on December twelfth,
sixteen thirteen, but a year after Galileo had written to Castilli. On the
twenty first, a Dominican preacher in Florence, Tomaso Cassini, whose text for
the day was a passage in the Old Testament about the sun standing still during
Joshua's battle against the Amorites, he publicly attacked Copernicanism. In fact, his
goal was to get the Inquisition to open a formal investigation into Galileo. Galleo
evidently got word of these intentions. On the sixteenth of February. He sent
a letter in his own defense to Piero Dini, a sympathetic Roman clergyman,
suggesting that he might pass it on to the leading mathematician of the Jesuit order
and to the leading theologian on the Inquisition, Cardinal Betamini, which Dini promptly
did. In the end, what Galileo was hoping to do was to take
advantage of a rift between the Jesuit order and the Dominican order within the Catholic
Church. His hope was that the Jesuits would take his side against his Dominican
opponents. Now, meanwhile, the Archbishop of Pisa warned Castili against Copernicanism,
and Castily told the bishop that he had returned the letter to Galileo, but
that he would ask him for a copy. Castili promptly wrote to Galleo,
urging him to take this opportunity to make final revisions to his text. In
fact, Galileo already suspected that he had been denounced to the Inquisition in Rome,
and so on the sixteenth of February he had sent Deni a copy of
the letter, drawing attention to the possibility that this text might differ from that
being circulated by his opponents. What this strongly suggests is that Galileo altered the
text, and that the new text was a lot less aggressive than the prior
one. In the end, he didn't really have to be worried. The
Inquisition looked at the version supplied by the informants, thought the wording was sometimes
unfortunate, but that the arguments by and large were unexceptional. Galleo's fundamental premise
in his open letter to Castili was straightforward. The Bible is the word of
God, but it is adapted to human capacities. So are there are plenty
of statements in the Bible that we're not supposed to take is literally true.
Those are God's way of communicating, not with philosophers but with ordinary people.
Nature is, like the Bible, a book in which we can trace God's
doing. But nature is not adapted or modified in order to be understood by
us. So when it comes to scientific questions, our direct knowledge of nature
must always take priority over whatever the Bible may have to say on the subject,
because there are always grounds for uncertainty as to quite how the Bible is
to be interpreted. Now, honestly, matters might have just ended there.
Galileo had been denounced and he had been cleared. In addition, he had
protested his personal piety and willingness to obey. But the inquisition was now interested
in two questions. First, what else could be discovered about Galleo? And
second, probably the more important question, was Copernicanism itself, now to be
regarded as heretical in all cases. Tamaso Cassini shows up in the Galileo story
again in March of sixteen fifteen. There we find him summoned to Rome to
provide supporting testimony against Galileo. He alleged that Galileo preached three things. One
God is not a substance but an accident. Two God must be a physical
entity because he has senses, and number three, there are simply no such
things as miracles. At the time, all these allegations did next to nothing.
None of them were actually new allegations, and swiftly everyone assumed that Galileo
would be cleared of all charges. The Florentine inquisitor uncovered some evidence that Galileo
was an atomist, a natural philosophy proposing that the physical universe is composed of
fundamental, indivisible components known as atoms, but even that didn't gain much traction.
In fact, this whole line of inquiry just tended to go nowhere.
Indeed, in the eyes of the Florentine inquisitor, it was convenient that it
should. The Archbishop of Pisa had vouched for Castilli, insisting there was nothing
suspicious in his claim that he no longer possessed Galileo's letter. The inquiry had
been delayed, and everyone had been gently reminded that Galileo was under the protection
of the Medici family in Rome. They could see that there was no point
in banging their heads against a brick wall. But we need not be as
quick as they were. Its lego of these questions for the conversations of Galileo's
disciples are interesting. The charge of atomism was certainly well founded. Both Galileo
and his closest disciples were atomists. Soon after his return to Florence in sixteen
ten, for example, Galleo converted the young Giovanni Camillie to atomism, a
doctrine Camillii remained firmly attached to for the rest of his life, and Galleo's
own account of his position seemed to leave no room at all for belief in
miracles, which suggests that the rumors that his disciples were moving around was accurate.
Moreover, we know things now today that the Inquisition simply didn't know.
We know much more about Galleo than they did. It's really a striking fact
that in the hundreds of letters written by Galileo that survived, there's absolutely no
spontaneous expressions of piety. Such expressions occur only when he has himself been charged
with impiety and This was really against the norm. And I have to stress
that if you look at all the correspondences from people throughout the early modern period,
expressions of piety, spontaneous expressions of piety extremely common. In fact,
there was no attempt to invoke the ordinary, almost routine miracles that formed a
part of counter Reformation spirituality. Now this is actually in opposition to Benedicto Castilli.
Castilli was a scientist. He was both a Copernican and an atomist,
but he was also a monk who was extremely pious. When he was seasick
and feared drowning, he asked that his abage should be told so that he
can pray for him. When Castily was ill, we have writings where he
was praying to Saint Philip Needy and the saint, according to him, here's
him in church. He writes how he sometimes hears sermons that feed his soul.
If you're looking for evidence that you can be an early modern scientist and
a pious Catholic, then Adito Castily is that evidence. And the problem that
we get into with Galleo a lot of times is that so many, especially
early modern biographers, want to desperately prove that he was a good Catholic in
addition to being a great scientist. Now the problem, of course in all
of this is Galileo is not, and never was Beneditto Castilli. We have
no evidence of Galileo praising preachers, or praying to saints, or even purchasing
indulgences. Only rarely does he ask others to pray for him. Frankly,
this might be one of those times when the lack of evidence becomes evidence.
Galileo is utterly silent on religion. One contemporary wrote, quote, Galileo never
spoke of Jesus end quote. There's no direct evidence as to what he thought
about Christ. So, like other men of his age, I mean recall
neither Cortes nor pis Ro wrote about their piety, we might have considered him
quite agnostic. Galileo, unlike many of his contemporaries, seems to have been
quite unwilling to admit that God would or even could intervene in historical time.
And there are more examples of Galileo's alleged impiety. In sixteen twelve, Julius
Caesar le Galla had argued that, if it were up to nature, the
entire surface of the world would be covered with water, but God, by
his peculiar providence, had arranged for there to be dry land. Galileo's response
to this was not pious in the least. He wrote, quote, if
water does not cover the entire surface of the globe because providence of the divine
architect, then you should not say that it would be more in accord with
nature if water covered the entire surface of the globe. For this Providence has
imposed much better laws on parts of the universe than that nature. Assuming that
is that it is appropriate to distinguish providence from nature in this way end quote.
Galleo is saying two things here. First, providence only operates through general
laws. There's no such thing as a particular providence, of which Lagala writes
this is one hundred percent heretical, by the way, so we should not
be surprised if it's implicit rather than explicit in Galleo's comment. And second,
if providence only operates through general laws, then there's no meaningful distinction between providence
and nature, between divine decree and natural regularity. In other words, the
entire concept of God itself becomes superfluous. Now. Frankly, at this point
it looks like the Florentine inquisition was probably right. The fact that the case
was dropped ultimately for a lack of evidence doesn't mean that the charges were mistaken.
But the Roman inquisition, unable to proceed further, simply returned to an
earlier claim that Copernicanism should be regarded as heresy, and if Galleos says anything
about Copernicanism, then that's it, end of story. According to some,
Galileo had avowed his Copernicanism in his letter on Sunspots, so the inquisition ordered
that a copy of the text should be supplied to a panel of theologians on
the February twenty fourth, sixteen sixteen. These theologians proceeded to condemn to propositions
number one that the sun does not move, which they held to be quote
foolish and absurd in philosophy, and formally heretical, since it explicitly contradicts in
many places the sense of the Holy Scripture, according to the literal meaning of
the words, and according to the common interpretation and understanding of the Holy Fathers
and the doctrine of theology. End quote. That the earth moves and rotates
once a day, which was held, if not heretical to be quote,
at least erroneous in faith end quote. To put it bluntly, this condemnation
was inevitable. Yet even staunch Jesuits were not interested in totally bad discussions of
Copernicanism. They were happy to admit that Copernicus's calculations offered mathematicians a superior model
for calculating the positions of the heavenly bodies. You could do all that without
saying that Copernicus's conclusions were true. What we have going on at the start
of the seventeenth century is this kind of i'll say, uneasy truths. The
Church could not ignore that Copernicus's math was correct, but it refused to admit
that his conclusions were correct, a bizarre status quota, said the least.
Like the Aristotelian philosophers, they were more than happy to accept all of Galileo's
telescopic discoveries. What they would not accept is that those discoveries proved that Copernicanism
was true. What all this information conveyed to Caalleo, though, was that
there was no real danger for him right now. Could keep doing what he
was doing and making discoveries and that wasn't going to imperil his well being.
That wasn't enough for Galileo. He balked at the suggestion that Copernicanism wasn't compatible
with the scriptures. Galleo insisted it was. He wanted to prove that Copernicanism
was true. It wasn't enough for Galileo to be allowed to make new discoveries.
He wanted to be able to prove what those discoveries meant, and to
do that he decided he would go to Rome. The Florentine ambassador to Rome
nearly fell out of his chair when he heard the news. This was not
the time. He frantically wrote to Galileo to try and get Roman authorities to
adopt new ideas. The present pope was extremely conservative, but Galileo would not
be dissuaded, and as soon as he rived in Rome, he felt like
he was directly engaged with battle in his opponents, and his health improved everywhere
he went. He announced that Copernicus had provided an account of the physical structure
of the universe and not a mere mathematical model. Onlookers admired his performances,
while completely unconvinced by his reasoning. By bringing the conflict out into the open
by refusing to compromise, by insisting that matters be settled one way or the
other. Galileo hoped to obtain one thing above all else, peace of mind,
but it didn't do any good. He soon found that people who counted
were willing to take delivery of written arguments, but not willing to enter into
open discussions and debates. So Galileo shifted tax and he did put all of
his arguments into writing. And it's a good thing too. Because he put
all of his arguments into writing, we can reconstruct exactly what they were.
And this is by far and away Galileo's strongest advocacy of Copernicanism. So he
wrote five main claims. First, that Copernicus had never intended to provide an
account of how the universe is really constructed, only to brought an aid in
calculation. Second, Copernicus need not be taken seriously because there were hardly any
Copernicans. If Copernicanism was right, would have general support. But Galleo insisted
that there were more Copernicans than were generally recognized, particularly as many were cautious
about declaring their views in public. But he also tried to turn a major
weakness in his position into a strength. What was crucial was that every Copernican
had once been an orthodox Aristotelian. How then to explain their conversion. The
only possible explanation, he claimed, was the strength of the arguments in favor
of Copernicanism. Galleo thus sought not entirely successfully be said to turn being a
minority from a disadvantage into an advantage. Where his opponents were happy to declare
a bias in favor of tradition, he was prepared to argu in favor of
a bias toward innovation. New arguments were more likely to be right than old
arguments, because new arguments implied new thinking. And his third claim that because
theology was the leading edge of science, it was perfectly proper for theologians to
settle disputes between astronomers. Here, Galileo argued that one had to distinguish between
the subject matter of a body of knowledge and the expertise of those who studied
it. The subject matter of theology, which concerned itself with the salvation of
souls, was certainly superior to the subject matter of astronomy, but this Galleo
argued, did not make theologians expert in astronomy. In arguing in favor of
technical expertise, Galileo was presenting a claim that seems absolutely obvious to us,
but that would have seemed much less obvious to his contemporaries. In the first
place, Renaissance culture was much more unified than ours is. Every theologian had
studied philosophy, including astronomy, before studying theology. It was therefore plausible to
insist that every theologian was capable of understanding and evaluating the arguments of astronomers.
Second, in a society in which was sharply stratified between those who performed manual
labor and those who did not, it was perfectly normal for gentlemen to give
orders to builders, armorers, estate managers anyone, even though they lacked any
specialist expertise. In arguing that there were some choices that were properly the preserve
of experts, Galileo was defending a new type of authority. Galileo that had
to overcome the most important of all arguments, the argument that the Bible could
not be wrong when it's said that the sun moved here Galleo struck once more
a unique argument. He argued that the Bible should be read in light of
current scientific knowledge, rather than science be reconstructed to fit the Bible. In
making this argument, Galleo cites Augustine eight times, Saint Jerome three times,
and a myriad other Biblical authors. Now, it would be easy to form
the impression from all of these different citations that Galileo was widely read in matters
of theology. Indeed, this is certainly the impression he wants to give the
person reading his arguments, but it would be a false impression. Sadly,
it seems contradicting his claims of genuine piety. All of Galleo's theological arguments were
second hand. Sources of them were primary sources. All those eight citations from
Saint Augustine actually came from other people's arguments. While the Inquisition in Rome was
willing to admit that Copernicanism might be theoretically possible, they told Galileo that he
needed proof, and specifically that he needed proof that the Earth moved. Galileo
believed he did have such proof in the form of the Earth's tides. He
confided this to the cardinal whom he felt most sympathetic to his cause, Cardinal
Orsini. Galleo's theory of the tides was straightforward. The speed at which different
parts of the surface of the Earth moved through space varies. Because the Earth
is both orbiting the Sun and rotating on its axis, two constant movements produce
a combined movement, which involves acceleration and deceleration. The result on long bodies
of water that run from east to west is that water piles up at one
end or the other, creating tides. Now, of course, many have
claimed that there's a simple logical error in Galileo's argument. They maintain that while
acceleration and deceleration may be apparent to someone looking at the Earth from an external
fixed point, they would never be apparent to someone on the surface. This
is just wrong, and the physical principle Galleos invoking does exist, but it
does not play a noticeable role in the formation of the tides, which is
of course caused by the gravitational pull of the Moon and the Sun. By
the time Galileo was ready to publish, he knew that tides varied in power
and condition. He also understood that there were two tides per day, not
one. These were issues he would need to account for in any publication.
Galleo's theory of tides was thus defective, it was odds with the fact,
and it was internally inconsistent. But in sixteen sixteen he offered a second supplementary
argument in support of the Earth's rotation, the fact that the trade winds blow
from east to west. Now, of course, it so happens that the
rotation of the Earth is the true cause of the directionality of the trade winds.
Bacon, in a text surely unknown to Galleo, had tried to explain
this phenomenon, sticking to Ptolemy as a result of the rotating heavens rubbing against
the Earth, and the possibility of such an explanation may have prevented Galileo from
laying nearly as much weight on the argument from the trade winds as on the
argument from the tides. Moreover, nearly everyone has some experience of the tides,
while Galleo, like most Italians, had no experience with the trade winds,
making it a less plausible argument. But there's another reason why Galileo was
reluctant to acknowledge the supure periority of the argument from trade winds over the argument
from tides. He had invented the latter himself, while he had borrowed the
former from someone else. So Galileo marshaled all his arguments in favor of a
moving earth, in other words, in favor of Copernicanism. He knew very
little, however, about what was really going on. It took him quite
some time to establish that there was no prospect of his being found guilty of
heresy, and when he did, he promptly attributed to its own presence in
Rome and the skill with which he had presented his case, when in fact
there had been no danger from the day of his arrival. And this is
because of his greatest success with Cardinal Orsini, who, armed with galles argument
about the tides, approached the Pope on his behalf on the twenty fourth of
February, the very day actually, when the Panel of Theologians ruled once and
for all that Copernicanism was heretical. It was already too late. In fact,
it had been too late when Galileo first talked of coming to Rome.
But the decision of these theologians had now to be turned into a program of
action. On March the fifth, the Congregation of Index, part of the
Inquisition, issued a decree banning a book about the revolutions of the Earth and
banning all books that taught the Copernicanism was true. Now, to be clear,
there was no direct mention of Galileo's letter on sunspots, presumably indeference to
the Grand Duke of Florence, who had made it clear that he was going
to support his court mathematician. Even more surprising is that the word heresy,
which had been central to the judgment of the Panel in the Theologians, appears
nowhere in the Congregation's decree. Be that as it may. On the twenty
fifth of February sixteen sixteen, the Pope told the Inquisition to have a talk
with Galileo. They were to warn him that he must abandon Copernicanism. Specifically,
he was to be read out loud a warning directly from the Pope,
a sort of medieval cease and desist letter. Galileo was never to publicly support
Copernicanism again. Now this letter is of dramatic consequence to our story, because
years later Galileo is going to assert that he never heard the contents of the
letter. He will swear that if there ever was such a letter, the
Cardinals never read it to him as instructed. The question then becomes was Galileo
given a friendly warning or was he formally prohibited from supporting Copernicanism. To all
the lawyers who are listening, you will know that such a difference counts for
a lot, especially in this case. Now there is a text, and
this text, and we have it, does prohibit Galileo from defending Copernicanism quote
in any way whatever, either orally or in writing end quote. But of
course the question is is it real. When in the eighteen sixties the record
of the Inquisition's dealings with Galileo was made public, this document became the object
of heated debate. Some said that it was a forgery, introduced only into
the file in sixteen thirty three, about seventeen years later, in order to
make it easy to convict Galileo. Modern scholars, however, are nearly all
agreed that the document is genuine, and consequently that its warning was read to
Galleo. Thus, there would be three possibilities. One Galileo heard the letter
and didn't say anything. Two Galileo did hear the letter and verbally assented,
and three Galileo never got the letter at all. I want to be clear
in any case, the evidence is unequivocal, and that is that Galileo was
never handed the letter. He was never given the formal text, so unfortunately,
will always be stuck wondering was it truly read to him. Ten years
later, Galleo would prove unable to recall precisely what happened had he been formally
warned. He didn't think so, but he couldn't recall for certain We will
probably never know what happened that day. In the offices of the Inquisition,
certainly no one wrote down a transcript that being said. Yalleo was careful not
to mention Copernicanism in print for the next decade, So I think the proper
inference here is that he must have at least understood he was not to broach
the topic in public. On March the eleventh, sixteen sixteen, Galileo had
a private audience with the Pope. Again, we do not have a transcript
of what was said, but Galileo left feeling reassured. We know that from
his writings. The biggest takeaway for Galileo from the events of sixteen fifteen sixteen
sixteen was probably an intense mistrust of the courts. He did not like the
experience, and I can see why. I mean, he seemed to get
assurances that everything was fine from multiple people throughout the process, including evidently the
Pope himself, and yet he was to some extent censured. But as we
will see next week in our final Galileo episode before we turn to the Inquisition
and his trial, any belief that he was safe was profoundly misguided. Now,
as always, if you're looking for more content before next week, you
can get a free trial of Western Sieve two point zero were past the wars
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