Historical Mock TrialThe Case of Galileo Galilei

Background

Stipulated Facts

Born in 1564 in Italy, Galileo Galilei became a brilliant scientist and lecturer. He made severalinventions, including the telescope. He was also devoutly religious Roman Catholic.

Galileo learned of an supported the theory of Nicolaus Copernicus that suggested that the sun was thecenter of the universe and that the earth revolved around the sun once a year on its axis. The accepted viewwas that the earth was the center of the universe and that the sun rotated around the earth.

In 1616, the Pope, the spiritual leader of the Roman Catholic Church, summoned Galileo to Rome towarn Galileo to abandon his opinion about the earth rotating around the sun; and “in the case of his refusal toobey, the Commissary of the Holy Office is to enjoin him to abstain altogether from teaching or defending theopinion and even from discussing it.” The account and writings are not certain whether there was a formalinjunction or order banning Galileo from holding, teaching, or defending the opinion that the sun is the centerof the universe and that the earth move. Due to the way the Injunction of 1616 was entered into the records,there is some suspicion that the Injunction was put into the record by Galileo’s enemies at a later of time.

In 1623, a new pope, Urban VIII, was elected. He was more open-minded. The new Pope’s privatesecretary wrote to Galileo, urging him to resume publication of his ideas. Galileo began work on a book,Dialogue Concerning the Two Chief World Systems.

Galileo submitted his book to the Vatican’s chief licenser, Niccolo Riccardi, who promised his help to getthe book published. Urban stated that if the book treated contending views hypothetically and not absolutely,the book could be published.

The chief licenser demanded certain revisions be made. After the revisions were submitted, thelicenser granted the permission for the book to be published.

The first copy of Galileo’s book came off the pres in February 1623 and quickly sold out. However, in thelate summer 1632, Rome ordered publication of the book to be suspended. Pope Urban VIII withdrew hissupport of Galileo, claiming that Galileo deceived him.

CrimeGalileo was charged with violating the 1616 injunction against teaching, defending, or discussing the

Copernican Theory; this carried the possibility of imprisonment and death.

Role: Judge● Read all court documents prior to trial● Presides over the case● Instructs the jury● Rules on objections

Order of Trial:1. Opening arguments from prosecution and then defense2. Call witnesses for prosecution and then defense3. Read the jury Instructions and explain reasonable doubt4. Allow closing arguments from each side5. Tell jury to discuss their decision (must be unanimous or there will be a hung jury)

Judge’s Instructions to Jury to Conclude the Case(Note: The judge reads these instructions to the jury prior to closing arguments)

To convict Galileo Galilei of the crime of violation of the 1616 Injunction against teaching, defending, ordiscussing the view that the earth revolves around the sun, the prosecutor must have proved each of thefollowing elements beyond a reasonable doubt:

1. That in 1616, the Pope issued an Injunction, forbidding Galileo from teaching, defending, or discussingthe view that the earth travels around the sun.

2. That on or about February 1632, Galileo Galilei published his book, Dialogue.3. That in the book, Dialogue, Galileo teaches, defends, and/or discusses the view that the earth moves

around the sun.4. That the book, Dialogue, violates the 1616 Injunction of the Holy Office not to teach, defend, or discuss

the view that the earth moves around the sun.

Role: Baliff● Read all court documents prior to trial.● Ensure the order of the court.● Remind court attendees to remain silent until called upon.● Write down names of those who contribute to disorder, do not pay attention, or are not prepared

when called upon.● Critique each role for effectiveness and professionalism.● Hand in notes of participants and offenders at the end of the court (will remain confidential only to be

seen by the teacher)

Role: Prosecution Attorneys (Team of 2)You are a devout Catholic who wants to protect your beliefs at any costs. Galileo has not only gone

against the orders of the Pope, but he has also suggested ideas that go again your Christian beliefs. You hopeto silence these ideas of heresy so that Galileo cannot cause anyone to challenge the truths of Christianity.● Read all court documents before the trial. Do extra research if desired.● Prepare an opening statement stating what the changes are against Galileo and which way you believe

that the jurors should vote (guilty of course). Your opening statement should be between 2 to 3minutes long and not more than 5 minutes. It should be a persuasive thesis detailing why your wantGalileo to be found guilty and set up your argument.

● Call your two witnesses (Pope Urban VIII and then Tommaso Caccini).● Listen to the two Defense witnesses (Benedetto Castelli and Galileo).● Close your case with a final statement wrapping up your point (considering the statements of the

Defense witnesses). Your closing statement should be between 2 to 3 minutes long and not more than5 minutes. It should be a persuasive conclusion detailing why you want Galileo to be found guilty andset up your argument.

Role: Tommaso Caccini (Prosecution Witness)● Read the statement and other documents given to your before the trial.● Work with the prosecution to build their case against Galileo.● Read your statement aloud when called on during the trial.● Take notes on how the trial is going (your thoughts).

BackgroundFather Tommaso Caccini, a Dominican monk and inveterate scandal-maker, was the chief instigator of

Galileo’s troubles. On December 20th, 1614, Caccini preached a sermon in Florence that condemnedmathematics and alleged that Copernicancism was either heretical or very close to it. Caccini, a “turbulentignoramus,” contended that Copernicus’ Sun-centered system contradicted Scripture’s description of anEarth-centered system.

In March of 1615, Caccini traveled to Rome and denounced Galileo before the Holy Office. In hisdeposition, Caccini claimed that Florence was full of “Galileists” who denied miracles, claimed God was anaccident and espoused Copernican views. Caccini’s move was part of a plot calculated to force Rome to actagainst Galileo.

Galileo accurately sized up his enemy, describing Caccini as a person “of very great ignorance, no less amind full of venom and devoid of charity”. Caccini’s own brother shared this appraisal, call his sibling “adreadful fool” whose “ugly drives” and “performance…makes no sense in heaven or earth.”

After playing his role in gaining Galileo’s admonition in 1616, Caccini managed to earn the enmity ofpowerful Cardinal Borghese and was forced to leave Rome. He spent later years as Prior of San Marco inFlorence.

StatementMy name is Father Tommaso Caccini, and I am a Dominican monk. I have been aware of Galileo Galilei

and his heretical beliefs for a long time. On December 20, 1614, I preached a sermon in Florence thatcondemned Galileo and his views on Copernican theory. Yes, I stated that Copernicanism was either hereticalor very close to it. It is clear that Copernicus’s sun-centered system contradicts Holy Scripture’s description ofan earth-centered system. For instance, in Joshua 10:13, the Scripture says, “So the sun stood still in the midstof heaven” and in Isaiah 40:22, it speaks of “the heavens stretched out as a curtain” above “the circle of theearth.”

In March of 1615, I traveled to Rome and denounced Galileo before the Pope. In my deposition at thattime, I reported that Florence was full of followers of Galileo, who denied miracles occurred, claimed God wasan accident, and espoused Copernican views. Rome had the intelligence to take action at that time to stopGalileo and the spread of his lies.

I was present when Pope Gregory XV admonished Galileo in 1616 and enjoined, that is prohibited,Galileo from teaching, defending, or discussing the idea that the earth moved around the sun. Galileo agreedto this injunction in 1616 and has now, through his latest book, Dialogue, violated the Injunction of the HolyCatholic Church. He must be punished severely.

Role: Pope Urban VIII (Prosecution Witness)● Read the statement and other documents given to you before the trial.● Work with the prosecution to build their case against Galileo.● Read your statement aloud when called on during the trial.● Take notes on how the trial is going (your thoughts).

BackgroundBorn Maffeo Barberini into a powerful family of Florentine merchants, he graduated from Collegio

Romano, then earned a doctor of law degree from the University of Pisa. Barberinini rose rapidly in the Churchhierarchy. In 1606, he was appointed cardinal and, with the death of Pope Gregory XV in 1623, he was electedPope, taking the name Pope Urban VIII. As Pope, Urban VIII made it his goal to reinvigorate papal power.

In the early days of his reign, Galileo had reason to believe Maffeo Barberini’s elevation to Pope mightlead to a loosening of the Church’s opposition to Copernican thought. Pope Urban VIII received Galileo for sixlong audiences. Although a humanist largely baffled by scientific principles, Urban VIII seemed genuinelyinterested in Galileo’s ideas. Urban VIII assured Galileo that as long as he remained Pope, the memory ofCopernicus had nothing to fear.

Eventually, however, the Pope’s pride and suspicious would produce the dramatic confrontation withGalileo that culminated with his arrest, and trial in 1633. The troubles developed after Pope Urban VIII gaveGalileo permission to write a book discussing the contending views of the universe: his Dialgue Concerning theTwo Chief World Systems. Galileo’s biggest mistake seems to have been putting into the mouth of an ignorant,literal-minded character name Simplicio which held the Pope’s own views, offered to Galileo in 1623,concerning God’s omnipotence. Urban VIII had argued that an all-powerful God could make the sun and otherheavenly bodies do as he pleased – notwithstanding the laws of physics. In his Dialogue, Galileo provided aresponse that must have made the Pope feel foolish: “Surely, God could have caused birds to fly with theirbones made of solid gold, with their veins full of quicksilver, with their flesh heavier than lead, and with theirwings exceedingly small. He did not, and that ought to show something. It is only in order to shield yourignorance that you put the Lord at every turn to the refuse of a miracle.”

Upset with what he saw as ridicule of his argument and convinced that the Dialogue was nothing but athinly-veiled brief for Copernican model, the Pope swung the machinery of the Church into motion againstGalileo. The Pope insisted upon a formal sentence, a tough examination of Galileo, public abjuration, and“formal prison.” In June 1633, the Pope got his wish.

StatementI was born in Florence, where my father’s family were merchants. I graduated from the Collegio

Romano and then earned a doctor of law degree from the University of Pisa. I was fortunate to be able to riserapidly in the Church hierarchy. In 1606, I was appointed cardinal, and with the death of Pope Gregory XV in1623, I was elected Pope.

In the early days of my reign, I did have discussions with Galileo on Copernican thought; I was genuinelyinterested in Galileo’s ideas. On at least two occasions, I did assure Galileo that as long as I did make it clearthat Galileo must speak hypothetically, not absolutely, about the Copernican views.

However, once I read Galileo’s Dialogue, I was convinced that it was nothing but a thinly veiled brief forthe Copernican model, something I had expressly forbidden. Galileo had deceived me, violated the injunctionof 1616, and deserves to be punished for his disobedience.

Role: Defense Attorneys (Team of 2)● Read all court documents before the trial. Do extra research if desired.● Prepare an opening statement stating what the charges are against Galileo and which way you believe

that the jurors should vote (not guilty of course). Your opening statement should be between 2 to 3minutes long and not more than 5 minutes. It should be a persuasive thesis detailing why your wantGalileo to be found not guilty and set up your argument.

● Call your two witnesses (Benedetto Castgelli and then Galileo).● Listen to the two Prosecution’s witnesses (Pope Urban VIII and Tommaso Caccini)● Close your case with a final statement wrapping up your point considering the statements of the

Prosecution’s witnesses).Your closing statement should be between 2 to 3 minutes long and not morethan 5 minutes. It should be a persuasive conclusion detailing why you want Galileo to be found guiltyand set up your argument.

Role: Benedeto Castelli (Defense Witness)● Read the statement and other documents given to you before the trial.

● Work with the defense to build their case for Galileo.

● Read your statement aloud when called on during the trial.

● Take notes on how the trial is going (your thoughts).

BackgroundBenedetto Castelli, a monk of Montecassino, ranked as Galileo’s favorite disciple. The two often

exchanged warm letters on matters ranging from scientific topics to the quality of wine and cheese. One letterfrom Galileo to Castelli in 1613, offering his views on matters theological and Copernican, became keyevidence leading to his 1616 admonition. That same year Castelli received an appointment as a professor ofmathematics at the University of Pisa.

Castelli had a first-rate mind. He understood Galileo’s thought as few men of the time did, and wrotehis own treatise of The Motion of Water. He served as chief consultant on hydraulic projects beginning in 1626and, later, as “Father Mathematician of His Holiness.” In the latter capacity in 1633, Castelli tried to explain themeaning of Galileo’s Dialgoue to his Inquisitors.

Before Galileo arrived in Rome to stand trial, Castelli was sent to Brescia. He was allowed to return toRome only after Galileo’s departure.

StatementMy name is Benedetto Castelli, and I am a monk. In 1616, I received an appointment as a professor of

mathematics at the University of Pisa. I have studied and communicated with Galileo over many years,discussing everything from scientific topics to the quality of wine and cheese. Unfortunately, one letter fromGalileo to me in 1613 became key evidence against Galileo that lead to his 1616 admonition. In this letter,Galileo had offered his views about Copernicus. Galileo wrote to me that when he first used his telescope andbecame the first human to see the Milky Way, the valleys and mountains of our moon, and the moons orbitingaround Jupiter, he gave “infinite thanks to God for being so kinds as to make me alone the first observer ofmarvels kept hidden in obscurity for all previous centuries.”

Because of our long-standing relationship, I believe that I understand Galileo’s thought as few othersdo. I will try to explain the meaning of Galileo’s Dialogue.

Galileo has repeatedly acknowledged that the scripture is truth itself. However, he believes that theScripture must be understood sometimes in a figurative sense. A reference, for example to “the hand of God”is not meant to be interpreted as referring to a five-finger appendage, but rather to His presence in humanlives. Given that the Bible should not be interpreted literally in every case, Galileo believes that it is a senselessto see it as supporting one view of the physical universe over another.

In Dialogue, Galileo has attempted to present the two different views of the universe and leave it up tothe readers to draw their own conclusions.

Role: Galileo Galilei (Defense Witness)● Read the statement and other documents given to you before the trial.

● Work with the defense to build their case for you.

● Read your statement aloud when called on during the trial.

● Take notes on how the trial is going (your thoughts).

BackgroundGalileo Galilei was a great scientist—but much more than that. Had he been content to stick to his

science—and limited his writing to dull treatises for other specialist—he would have never incurred thecondemnation of the Catholic Church. Galileo had a mission: he wanted to increase awareness of scientificthought and, in the process, rescue the Catholic Church from its ostrich-like refusal to see the cosmos as itreally was.

Galileo was born in Pisa in 1564—the same year Shakespeare was born and Michelangelo died. In the1570s, Galileo and his family moved to Florence. In 1581, he entered the University of Pisa, as a student ofmedicine and philosophy. At Pisa, Galileo undertook a study of the pendulum that would much later result inthe development of the pendulum clock. In 1592, Galileo was appointed professor of mathematics at theUniversity of Padua. In that position, Galileo pursued interests in the motion of falling bodies, sphericalgeometry, nautical engineering, and astronomy. During this period Galileo also came to accept the view ofCopernicus, first developed in his treatise on the Revolutions of the Celestial Orbs, that the Earth, rotating oncea day on its own axis revolved around the sun.

In 1609, shortly before resigning his position at the University of Padua, Galileo produced the world’sfirst working telescope based on a spyglass shown by a Dutch eyeglass maker. Galileo used his telescope for aseries of remarkable astronomical discoveries, including the Milky Way, the moons of Jupiter, the phases ofVenus, sunspots, and numerous lunar features. Drawing from these discoveries, Galileo proposed newarguments for the Copernican system—and presented these arguments in a series of letters.

Galileo’s eagerness to express Copernican views would earn him first, in 1616, an admonition from theCatholic Church and later, in 1633, a trial for violating and injunction – supposedly issued seventeen yearsearlier – against holding, teaching, or defending Copernican views. Galileo was nearly 70 years old at this timeand was gradually going blind most likely caused by prolonged exposure of his eyes to direct sunlight with histelescope.

StatementI have always been interested in science. I began my studies as a student of medicine and philosophy in

1581 at the University of Pisa. My first research focused on the study of the pendulum, which I understand hasnow been developed into the pendulum clock.

It was while I was a professor of mathematics at the University of Padua that I became interested inmotion of falling bodies, spherical geometry, and astronomy.

During this period, I learned of the writing of Nicolaus Copernicus, a Polish scientist. He wrote a treatiseon the revolutions of the Celestial Orbs, that the earth, rotating once a day on its own axis, revolved around thesun. After inventing the world’s first working telescope in 1609, I was able to see remarkable astronomicaldiscoveries that supported the theory that the earth rotated around the sun. I made new arguments for theCopernican system – and presented these arguments in a series of letters.

I should also say that I am a very strong believer in God and a devout member of the Roman CatholicChurch. In fact, all my discoveries show the work of God in creating this fabulous universe. However, I hadenemies who were afraid to embrace these new discoveries. My mission was to increase awareness of

scientific thought and, in the process, rescue the Catholic Church from its ostrich-like refusal to see the cosmosas it really is. In 1616, I was called to Rome, and Pope Gregory XV admonished me against holding my view thatthe earth moved around the sun. I am 70 years old now and in bad health, and I do not remember exactlyeverything about the case of 1616. However, I do not think that I was ordered not to teach, defend, or discussthe sun-centered theory of the universe.

When I returned home from Rome in 1616, I abandoned investigation of this issue. However, when anew pope was elected, Pope Urban VIII, his private secretary contacted me and asked me to once again renewmy investigations. During the early years of Pope Urban VIII’s reign, he and I had long discussions, includingdiscussions of the Copernican systems.

As required by the Pope, I submitted the book to the Vatican’s chief licenser, Niccolo Riccardi, whopromised his help and said that any theological difficulties could be overcome. Even in 1630 when I went toRome, the Pope was very encouraging. He repeatedly said that if the book treated the contending viewshypothetically and not absolutely, the book could be published.

Chief licenser Riccardi had some problems with the book and demanded that I revise the preface andconclusion to be more consistent with the Pope’s position. I made those changes as requested. Finally, inFebruary 1632, with the chief licenser’s permission, the book was published. I was very pleased that the book,which quickly sold out, soon became the talk of the literary public.

Then in late summer of 1632, the Pope ordered publication of the book to be suspended. OnSeptember 5, Pope Urban told Francesco Niccolini, who had come to the Vatican to protest the suspensedecision, that I had deceived him by assuring him that the book would comply with papal instructions, when infact I had circumvented the. This is absolutely not true.

I am angry. My goal has been to spread scientific awareness to the public. Instead I have beenfrustrated by a narrow-minded bureaucracy intent on preserving its own power. I have done nothing wrong.Pope Urban VIII authorized me to write about Copernicanism, I followed the required form, I even revised mywork to meet the censor’s objections, and I obtained a license. What more could authorities expect? Howcould the law now punish me when I have acted with such care?

Role: Jury● Read the background information given to you and answer any applicable questions.● During the trial take notes on what is said.● Listen to the instructions of the judge.● Vote on your decision.● Complete the reflection sheet given to you.

BackgroundNicolaus Copernicus was an astronomer who is best known for the

astronomical theory that the Sun was near the center of the universe andthat the Earth and other planets rotated around the center. He also statedthat the Earth spinning on its axis, rotates once daily and makes a fullrevolution around the Sun in a year.

Copernicus did not believe that the Earth and other planets wereinfluenced by or revolved due to the Sun; instead he believed that the Sunwas located near the center of the universe. It was this center of theuniverse which influenced those bodies and caused them to revolve. Thistheory is called heliocentric or sun-center theory of the universe.

Copernicus grew up in Poland and was given a solid education dueto the influence of his uncle who was a bishop. He moved to Italy to further his studies in 1495 at the age of22. It was there at the University of Bologna that Copernicus became very interested in astronomy. Hebefriended one of his professors name Domenico Maria de Novara who was very skeptical of the Ptolemaicview of the universe. Copernicus began to share his skepticism and he began to look for a solution that wouldresolve the problems with the wide spread theory about the universe.

Sometime between 1507 and 1515 he completed a short paper entitled “Commentariolus.” Eventhough it was not published till the 19th century, it was important because it served as the basis for his radicallynew theory of the universe. Shortly thereafter, in 1517, Copernicus began work on his major work, On theRevolutions of the Celestial Spheres, which he did not complete until 1530. However it was not published until1543, just before Copernicus died.

The Copernincan Heliocentric TheoryYou must have a little background on the

accepted Ptolemaic view of the Solar System inorder to understand the difference between it andthat which Coper nicus theorized. Scientists believedthat the Earth was fixed at the center of the universeand surrounded by several concentric rotatingspheres which were the planets, sun and moon. Onthe outermost sphere, picture the inside of aballoon, where the stars which were fixed. Thisoutermost sphere was said to wobble slightly toaccount for the procession of the equinoxes. Therewas one question that this system brought up thatpuzzled scientists: Why did Mars, Jupiter, and Saturnevery so often appear to move across the sky in onedirection and then seem to stop opposite direction, what they called retrograding across the sky? To explain

this phenomena Ptolemy proposed that the planets, sun, and moon moved in small circles while traveling intheir much larger obits around the fixed Earth. These small circles were called epicycles, but many scientistsdid not see this as the answer. The heliocentric theory would explain why the planets seemed to retrogradeacross the sky.

The Copernican theory explained many of the observations of astronomers. Some of itsrevolutionary ideas were that the Earth rotates on its axis daily and revolves around theSun once a year. The heliocentric theory retained many of the characteristics of itspredecessors, one key concept it embraced was planetary spheres, the other most spherecontaining the stars. Copernicus knew that his explanation was not completely correct.Among other things, he realized that the rotation of Earth in its orbit would cause a

continuous repositioning of the stars in the sky. He resolved this by posing that the distance between the Earthand the outer sphere which contained the stars was so great that any variation in the position of the starswould be almost undetectable. However, in the heliocentric theory the outermost sphere containing the starswas stationary. The heliocentric system did resolve many of the problems with its predecessors; the apparentyearly motions of the stars and Sun, the apparent retrograde of Mars, Jupiter, and Saturn, and the face thatMercury and Venus never travel more than a certain distance from the Sun. Copernicus reordered the planetsaccording to the time it took for them to revolve around the center of the universe (near the Sun). UnlikePtolemy’s theory of the universe, the larger the radius of the planet’s orbit, the longer it takes to make onerevolution.

InfluenceWhen the Copernican theory was first published it was not accepted by the scientific community. Even

though it was physically sound, the calculations of astronomical positions were not made much simpler,neither were these calculations much more accurate. Tycho Brahe, developed a middle position between thetwo theories which was more widely accepted. Some of the most famous heliocentric theory supporters wereGalileo Galilei, Johannes Kepler, and of course Sir Issac Newton who helped explain the force, gravity, that allbodies exert on each other.

ResultIn late 1633, Galileo was found guilty of violating the 1616 injunction and ordered to house arrest for

the remainder of his life. In 1741, Pope Benedict XIV asked the Holy Office to grant an imprimatur (Churchapproval) to the first edition of the Complete Works of Galileo, thus acknowledging the validity of Galileo’sperspectives. In 1979, Pope John Paul II requested that the Pontifical Academy of Sciences conduct an in depthstudy of the Galileo case. A commission of scholars was convened, and they presented their report to the Popeon October 31, 1992. Following the guidelines of the Second Vatican Council, Pope John Paul II issued anapology to Galileo Galilei, wishing to make clear that science has a legitimate freedom in its own sphere andthat this freedom was unduly violated by Church authorities in the case of Galileo.

Reflection Questions:

1. With what crime was the defendant charged?

2. What legal questions were raised by the case?

3. State the arguments of the prosecution.

4. State the arguments of the defense.

5. How did the prosecution try to prove its case?

6. Describe the strategy of the defense.

7. If you were an attorney for the prosecution or the defense, what facts or arguments would you havepresented?

8. What was the decision of the trial? Do you agree or disagree with the decision? Why?

9. Are there grounds for appeal? Why?

10. In your judgment, did the defendant get a fair trial? If not, why not?