The Galileo Affair
Topic2 + Quiz
“In matters that are obscure and far beyond our vision, even in such as we may find treated in Holy Scripture, different interpretations are sometimes possible without prejudice to the faith we have received. In such a case, we should not rush in headlong and so firmly take our stand on one side that, if further progress in the search of truth justly undermines this position, we too fall with it. That would be to battle not for the teaching of Holy Scripture but for our own, wishing its teaching to conform to ours, whereas we ought to wish ours to conform to that of Sacred Scripture.”
Augustine, Literal Meaning of Genesis, Bk. I, ch. 18; 1:41; cf. Bk. I, ch. 19; 1:41-42.
1. Watch the “From the vault: The Galileo Affair” video prompt for this assignment at Janux.
2. Share your thoughts in the Discussion at Janux.
3. Examine the supplemental resource: “Galileo’s Hermeneutics.” It’s supplied as a pdf in case you want to print it out.
“Hermeneutics” means “principles of interpretation.”
Let’s imagine we are a group of Cardinals called by the Inquisition (i.e., the “Congregation of the Index”) for consultation on the theological issues raised by Galileo. On the basis of our report, the Index will issue its decree. Let’s put ourselves in the position of these theologians: we have received their education and know all that they know about the world. (But we know nothing that occurred after Feb 20, 1616.)
4. Finish watching the video entitled “The Life and Works of Galileo: A Guided Tour." This is an hour-long overview of Galileo's life and works. While you watch, read the “Galileo Timeline” pdf. This is the second day of a two-day assignment: for this Topic 2 assignment, begin watching the video at 37:30, where the title slide for the next section “Scripture and Copernicanism” will appear, and then watch to the end of the presentation (watching the Q&A period afterward is optional). Read the companion pdf beginning with the section entitled “Scripture and Copernicanism.”
5. Quiz: Afterwards, take a Topic 2 quiz in the assignments area of Janux. The quiz will be composed of 12 of the true/false questions listed in the Study Guide. Topic 2 quizzes must be completed before Thursday night at 11:59 p.m.
Optional: Some additional print sources are recommended at LibraryThing.
For additional images, see the History of Science Collections Flickr collection for Galileo.
Script of the Janux "From the Vault" video:
Thanks for joining me in the History of Science Collections of the University of Oklahoma Libraries. Let’s look at a few treasures from the vault that throw a little light on the story of science and religion in the case of Galileo. The controversies over Galileo offer a paradigm example of how difficult it can be to promote interdisciplinary collaboration when emerging research fronts require novel methodologies. In Galileo’s case, practitioners of the established fields of both theology and physics were not ready to welcome Galileo’s mathematical methods or to relinquish their own traditional methods.
In 1615, in response to gathering criticism, Galileo had written a short reconciliation of Scripture and Copernicanism in a letter to the Grand Duchess Christina. In the Letter to Christina, Galileo argued that the purpose of Scripture is to tell us how to go to heaven, not how the heavens go; Scripture never errs, but its interpreters do err; and read rightly, Scripture and Science will never conflict (there is a unity of truth). That which is obscure (figurative language) should be explained by that which is clear (mathematical demonstrations). This is the first printed edition, which appeared in 1636.
Consider the wording of Psalm chapter 78 and verse 65 in this first edition of the King James Bible: “Then the Lord awaked as one out of sleep, and like a mighty man that shouteth by reason of wine.” Does this mean God is literally a drunken man? Of course not; biblical language is accommodated to common idiom and sensory perception, and not intended to teach us the invisible natures of things.
To show the traditional basis of his approach, Galileo cited St. Augustine throughout the letter. Augustine taught that the language of Scripture was accommodated to the understanding of ordinary readers and therefore not intended to impart theoretical knowledge in natural science.
Thomas Aquinas agreed, writing in his Summa that “that Moses was speaking to ignorant people and out of condescension to their simpleness presented to them only those things that are immediately obvious to the senses.” In theory, nothing would have prevented Roman Catholic theologians at the time from accepting the Copernican system, had they rigorously followed their own explicitly formulated principles of interpreting scripture. Copernicus himself was Catholic and dedicated the De revolutionibus to Pope Paul III. Pope John Paul II deliberately used Galilean language to affirm similar hermeneutical principles in 1992.
So perhaps it shouldn’t be surprising that the first defense of Copernicus in Spain was written by a theologian, Diego de Zuniga, in a commentary on the book of Job. His commentary on Job shows that Zuniga possessed a working knowledge of Copernicus’ system, including some of its technicalities. Other theologians came to Copernicus’ defense as well, but after the Council of Trent their efforts were looked upon with suspicion, as the Church sought to minimize novelties which, to the minds of the Council, were linked to the Reformation. After Trent, theologians did not pause to consider the potential reach of the new mathematical methodologies.
Johann Kepler wrote an essay reconciling Copernicanism and scripture, along similar lines as Galileo’s letter to Christina. It was published along with Galileo’s letter in this volume, the first English translation of any of Galileo’s works.
The controversy over the comets illustrates that the Galileo Affair, however tragic, was not inevitable. When three comets appeared in 1618, Oratio Grassi occupied the chair of mathematics at the Collegio Romano, the leading university run by the Jesuits in Rome. The Jesuits were charged with teaching nothing contrary to Thomas Aquinas in theology, and nothing contrary to Aristotle in natural science. Aristotle, in his Meteorology, taught that comets are vapors that occur beneath the Moon. Yet in this work, Grassi, a skilled astronomer, accurately determined the trajectory of the comets and proved that they moved through the heavens beyond the Moon. Did he get into trouble? Ironically, he met resistance indeed, but not from his own order. Rather, the pushback came from none other than Galileo himself.
In this book, Galileo’s own copy of his book Il Saggiatore, Galileo assailed Grassi for not understanding that the location of a comet is an optical illusion! It seems Galileo was particularly upset with Grassi for not defending Copernicus in his treatise on the comets, and yet Galileo’s fallacious argument, clothed in satire toward Grassi, marked an unfortunate rift between Galileo and the mathematically trained Jesuits. Nevertheless, Galileo dedicated Il Saggiatore to the pope, who received it delightedly.
This beautiful illustrated manuscript consists of Grassi’s lecture notes at the Collegio Romano in the very year Galileo published Il Saggiatore. Documentary sources for astronomy at the Collegio Romano are notably scarce; this manuscript is one of only a few astronomical manuscripts from the leading Jesuit university preceding the publication and subsequent condemnation of Galileo’s Dialog. What was Grassi actually teaching behind closed doors in the Jesuit university? It turns out that this manuscript shows that not only was Grassi teaching that comets move beyond the Moon, contrary to Aristotle, but he also discusses Gaileo’s telescopic discoveries, including imperfections on the surface of the Sun and Moon and the satellites of Jupiter. This manuscript is new to scholars and never before published; it was acquired with assistance from the OU Athletic Department in 2013. Go Sooners!
In any case, Grassi and the Jesuits show that a mind-numbing adherence to Aristotle’s Earth-centered cosmology was not inevitable in the Catholic Church. In this massive work (bound in two volumes), Riccioli offered his fellow Jesuit astronomers a thorough-going reformation of astronomy. With Ptolemy dead and buried, the Jesuits needed a new astronomy, a new Almagest, which Riccioli offered at mid-century. The frontispiece of Riccioli’s treatise depicts not two, but three major systems of the world. The Ptolemaic system rests discarded in the lower right corner. It could be rejected but not forgotten. While all-seeing Argus looks on, Urania weighs in a balance the two chief world systems which remain: Riccioli’s own system — a variant of Tycho Brahe’s — and the system of Copernicus. The Copernican appears as the standard against which alternatives must be measured.
As this episode suggests, some of Galileo’s strongest supporters were Jesuit mathematicians in the Church, who were leading astronomers. Some of Galileo’s strongest opponents were physicists in the Universities, who, like the post-Trent theologians, were unwilling to recognize the power of the new mathematical methods. Instead of a Conflict thesis, we need a Complexity thesis that interprets historical events as drama, as a story that might have turned out otherwise.
Science is a story. We have not even scratched the surface of the Galileo Affair.
What stories do you want to hear and tell about Galileo?
Optional: To read Galileo for yourself, why not begin with the excerpts from Galileo's writings (mainly The Starry Messenger) found in Michael Crowe, Theories of the World, ch. 9. Read pp. 159-173? Test your understanding with these optional study questions:
TOPIC QUIZ: The statements are either True or False. When you take the quiz at Janux, you will see 12 of these statements, chosen at random, 2 points each.
From the Vault video: The Galileo Affair
Galileo’s Life and Works: A Guided Tour (auxiliary video and pdf timelime)
“Books are not absolutely dead things, but do contain a potency of life in them to be as active as that soul was whose progeny they are; nay, they do preserve as in a vial the purest efficacy and extradition of that living intellect that bred them.... A good book is the precious life-blood of a master spirit, embalmed and treasured up on purpose to a life beyond life.” John Milton
This course is currently undergoing major reconstruction to bring it into alignment with the new version of the course at Janux