Bagnall Beach Observatory

MPC Observatory Code 433

The Galileo Myth

What Is a Myth?

For many people, calling something a myth means simply that it is not true. It is a false statement. However, this is an inaccurate understanding of the word, “myth”. For anthropologists and others who study human society, myths play an interesting role in any society. Myths are essentially stories that communicate the values and ideology of a society, or sub-group within it. A myth does not have to be literally true to communicate values and ideology, as many indigenous people appreciate. As one tribal chieftain explained, “I don’t know whether this story actually happened, but I know that it is true”.

There is a myth amongst one tribe of Australian Aborigines that the Larger and Smaller Magellan Clouds were created when a young man and woman broke the rules as far as their relationship was concerned and were cast out of the world. The Magellanic Clouds were supposed to be the holes they made as they were thrown out. To the scientist, this is nonsense. The Magellanic Clouds are satellite galaxies of our own. To the tribal member, the Magellanic myth uses a natural phenomenon to teach and remind people of tribal ideology about marriage.

 We should not imagine that myths are only the province of the hunter-gatherer. The telling of “history” is another means of perpetuating myths that communicate ideology. As some have cynically said, history is the mythology of the victor. Our politicians are famous for creating myths supposedly based on history. However, it is not only politicians. All of us project onto our sparse knowledge of history the ideology we hold. Ironically, many scientists, who would easily dismiss the myths of primitive societies as nonsense, are rather apt at projecting their ideology onto a myth supposedly based on history.

 There is often a great deal of emotion, and a great deal of vested interest, in historical myth. Woe betide those who uncover any fallacies! The reason is that people base their world-view on such myths, and any historical investigation that undermines the myth isn’t simply dabbling in historical accuracy, but people’s sense of security. Keep a check on your own emotional reaction as we explore the “Galileo Myth”.

The Galileo Myth

The “Galileo Myth” is described by science writer, Margaret Wertheim, as the popular mythology which construes the showdown between Galileo and the Church “as a simple battle between religious tyranny and scientific rationality” and in which Galileo is portrayed as “a caped crusader of the intellect, boldly defending truth, justice, and the scientific way …” In the constant re-telling of the story of Galileo, Galileo becomes the icon of scientific truth and the Christian Church (usually described without much sense of history in the singular) as the promoter of superstition and the oppressor of scientific truth. This spin on history is little more than mythology, or “myth-tory” as some have cynically called it. First, the Christian churches, (note the plural), were the chief promoters of scientific research in that era. Second, Galileo’s astronomical observations certainly brought him fame, but he suffered from an appalling inability to integrate them into astronomical theory. Third, while Galileo suffered persecution at the hands of the Roman Catholic Church, a much more adequate theory of heliocentrism was developed in Protestant seminaries of the time.

The Church and Science

One of the clearest explanations of the Christian Church’s approach to science at the time of Galileo is actually given by Galileo himself. In his Letter to Castelli (21 December, 1613), Galileo wrote:

“For the Holy Scripture and nature both equally derive from the divine Word, the former as the dictation of the Holy spirit, the latter as the most obedient executrix of God’s commands; …”

Galileo’s theological interpretation is even more fully developed in his Letter to the Grand Duchess Christina (1615) where he writes:

“… God reveals Himself to us no less excellently in the effects of nature than in the words of sacred Scripture, …”

Galileo goes on to quote Augustine and Tertullian in support of his arguments. Obviously these arguments did not begin with Galileo. They were part of Christian tradition he inherited, in which nature was understood to be a book which revealed God. However, while the early Church Fathers understood the Book of Nature to be speaking in allegories of the spiritual life, by the beginning of the second millennium the Book of Nature was being interpreted more literally by Christian thinkers. Nature, which hitherto had been a mere source of allegory for the spiritual life, was now being seen as a source of scientific knowledge which revealed God. This new approach to nature expressed itself in a new theology. In the 12th century, Hugh of St Victor (d.1142) perhaps most clearly expressed the thinking of his contemporary peers in declaring that the whole material creation consisted of letters written ‘by the finger of God’. There thus became two sources of revelation, with the Book of Nature standing alongside the Book of Scripture.  Professor Peter Harrison sums up the situation concisely: “Nature was a new authority, an alternative text, a doorway to the divine which could stand alongside the sacred page.” The exploration of the natural world was thus approached as a quest for the divine – an approach to Nature which characterised many of the great scientific minds of the second millennium.

Reflection on these theological assertions resulted in a new confidence in the material world as a means to the knowledge of God. As Peter Harrison puts it, “Albert the Great (c.1200-1280), sounding rather like an eighteenth century British empiricist, announced that all universal knowledge arises out of sense experience. His famous protégé, Thomas Aquinas (c.1225-1274), agreed that ‘all our knowledge takes its rise from sensation,’ and that ‘it is the knowledge we have of creatures that enables us to refer to God.’ “

In England, church functionaries devoted themselves to the discovery of God as revealed in Nature. Robert Grosseteste (1168-1253), first chancellor of Oxford University and later Bishop of Lincoln, pursued the study of light, explaining the rainbow as an outcome of refraction. His follower, Franciscan friar, Roger Bacon (1214-1292), wrote three major works campaigning for mathematics and experimental science. All of these men saw science, not as the enemy of religion, but as part of the religious quest. Roger Bacon credited science first and foremost as “the handmaiden of theology”.

The assumption that the natural world was a means of revelation of God became the chief impetus to the development of science, almost to the end of the second millennium.

So, far from being opposed to science, the Christian Church in the West saw it as a means to revelation of God, and this motivated an intense scientific search.

 

The Reformation and Science

On reflection, the Christian theological emphasis on the Book of Nature and the Book of Scripture as twin sources of revelation had a number of implications. First, it gave theological impetus to science. However, secondly it presented the challenge of reconciling those two “Books”. Thirdly, it raised the issue of the authoritative interpretation of those books. It is on the second and third issues that an historical event called the Reformation made such an important difference.

In reporting on the treatment of Copernicus’ theory of heliocentrism, many non-historians refer to the response of THE Church (in the singular). This is a glaring historical error. Apart from the division between Eastern Orthodox and the Western Roman Catholic Church in the 11th century, there was a major division in the Western Church caused by the Reformation in the 16th century. This division had major implications for the way in which heliocentrism would be dealt with. The Reformation was begun by Martin Luther, which led to the Lutheran Church. Other Reformers, such as Jean Calvin spawned other forms of Protestantism. The aim of these Reformers was not to set themselves up as alternative Popes, but to enable people to have free access to, and free interpretation of, the Book of Scripture. While the historical reality did not always live up to the ideal, it gave much greater freedom in addressing the challenges noted in the previous paragraph.

Copernicus’ theory of heliocentrism initially received a warm welcome from the Catholic Church, but as time went by the reception chilled until the banning of his book by the Catholic Church in its encounter with Galileo. However, in Protestant circles the reception was much better. Superficial analyses often make reference to an after-dinner remark by Martin Luther in which he is supposed to have expressed a negative view toward heliocentrism. The comment was recorded in Table Talk by students who were writing decades after the time of the remark and after Luther had died. The versions of the two students are quite different. More difficulty is created by the fact that, in these comments, Luther does not refer to Copernicus by name; and is supposed to have made the comments before Copernicus had published his book!

Ultimately, it makes little difference what Luther thought. The chief player on the scene was Luther’s right-hand man, Phillip Melanchthon. While Melanchthon may not have personally agreed with Copernicus, he gave generous leave to the professor of astronomy at his university, Georg Joachim Rheticus, to investigate Copernicus’ theory, write the best summary available of it, and ultimately take Copernicus’ book to the printers and oversee its publication. Rheticus spent months away from his work at the university living with Copernicus, grasping his ideas, and trying to persuade him to publish. Without Rheticus’ efforts, the world would probably never have heard of Copernicus. We should also lay to rest the tale that Rheticus was pushed out of his position at Melanchthon’s seminary because of his promotion of Copernicus. Rheticus’ move to another university was a promotion in which he secured a 40% increase in salary. Melanchthon would later support Rheticus with a good reference for a further enhancement of his academic career – hardly the efforts of an enemy!

After the publication of Copernicus’ book, his theory was handled in one of two ways. It was either regarded as a mathematical theory for the prediction of astronomical positions, without acceptance of the idea that the Sun was really physically at the centre; or it was accepted as a “real” view of the physical position of the Sun. The latter view was championed at the Lutheran seminary at Tübingen by a professor of astronomy and mathematics named Michael Mästlin.

Copernicus and Science

Before we get too excited about the promotion of Copernicus’ theory of heliocentrism, we need to take a reality check. Copernicus placed the Sun at the centre. He probably got this idea from the ancient Pythagoreans, whose ideas had been transmitted by Arabic scholars back into the European world. However, the reason for Copernicus’ endorsement of the idea was that it preserved the perfectly circular and uniform motion of the planets. This conviction about perfect circularity and uniform motion derived from the ancient Greeks and their conviction that objects in the “heavenly” realms represented mathematical “perfection”. The idea is completely false. Furthermore, in order to maintain this conviction, Copernicus had to have the planets not only tracing out perfect circles around the Sun, but spinning around on little epicycles as they went around the larger circles. Once again, this is pure fiction, and is certainly not science as we understand it today.

From Copernicus to Kepler

Into the Protestant seminary at Tübingen, where Michael Mästlin championed the “realistic” interpretation of Copernicus, came a young student by the name of Johannes Kepler. Kepler came from a family plagued by the domestic violence of his parents. He was too poor to secure an education on his own, but his brilliance had marked him out for a scholarship. Kepler was passionate about becoming a Lutheran minister. Because of the twin theory of revelation – the Book of Nature and the Book of Scripture – theological education in those days involved training in both the Arts faculty (which in those days covered science) and the Divinity faculty. While undergoing this training, Kepler discovered that he had a deep passion for astronomy and mathematics, which he confided to the staff of the seminary. As Kepler’s education came to a close, the staff guided him into a position where his passions truly lay; not as a Lutheran pastor, but as a teacher of mathematics in Graz. Kepler struggled with this change of direction and his sense of calling to the ministry, unable to see that he was to subsequently become one of the greatest mathematicians and astronomers that the world has ever known.

Kepler historian, James Voelkel, has traced the central ideas of Kepler through his works. First, Kepler totally endorsed the heliocentric theory. However, he had another conviction, even from his days as a theological student, which enabled him to transform Copernicus’s theory from ideology into science. This was the view that the motion of the planets around the Sun was caused by a force emanating from the Sun. Kepler’s views reached their pinnacle in the publication of his book, A New Astronomy (1609). Of course, this is an abbreviated title of the book, which was actually called, New Astronomy Based Upon Causes, or Celestial Physics, Treated by Means of Commentaries on the Motions of the Star Mars, from the Observations of Tycho Brae, Gent., by Order and Munificence of Rudolph II, Emperor of the Romans, & C., Worked Out at Prague in a Tenacious Study Lasting Many Years by His Holy Imperial Majesty’s Mathematician Johannes Kepler. With a title like that it is understandable that it be abbreviated. Unfortunately, the common abbreviation omits one of the central and then novel ideas introduced by Kepler – that the motion of the planets was caused by a physical force from the Sun. Perhaps it would be more helpful to an understanding of Kepler to refer to his book as, A New Astronomy Based on Physics. After many years of examining the empirical observations of Mars by Tycho Brae, Kepler was able to argue that the only theory matching the data was to have the Sun at the centre of the planets from which a physical force (gravity) emanated, causing the planets to orbit not in circles with epcicycles, but in ellipses. This brilliant insight has earned Kepler the title today of “The Father of Celestial Mechanics”. Part of the significance of Kepler’s insight was to remove Copernicus’ attribution of celestial motion to ancient Greek ideals of circularity and uniformity and base it firmly on the very physical forces that are experienced on Earth. In short, Kepler moved our understanding of celestial motion from ancient Greek ideology to physics.

Kepler’s genius did not stop there. He correctly explained the tides as being caused by the gravitational influence of the Moon. He also examined the telescope and the human eye and explained how the telescope worked.

It is interesting to pause and reflect on the journey from Copernicus to Kepler. The Catholic clergyman, Copernicus, renewed the ancient Pythagorean belief in heliocentrism. It was picked up by the Protestant scholar, Rheticus, passed on to the Protestant scholar, Mästlin, who passed it on to his brilliant student, Kepler, where it was transformed from ideology into science.

Comparing Kepler & Galileo

Johannes Kepler was a contemporary of Galileo Galilei. They corresponded on a number of occasions. The different treatment each received from their churches is instructive. Kepler’s first book espousing Copernican theory, Cosmographicum Mysterium, written a mere two years after leaving the seminary, received the unanimous endorsement of the Tübingen seminary senate. His later and more mature work, A New Astronomy Based on Physics, was never condemned by his church. It is true that Kepler decided to omit a theological chapter from his Cosmographicum Mysterium because he became aware that a former theological tutor was not happy with it. However, Kepler operated from a position of strength. The senate had approved it. However, Kepler had a very close and warm relationship with both his astronomy and theology teachers at the Tübingen seminary. As a devoted Lutheran, Kepler followed the strategy of St Paul when seeking to change people’s’ ideas. His decision to omit his theological treatise derived from his theological strategy of sitting with the weak in their weakness. No objection was ever launched by Kepler’s church against his astronomical theories, and the only conflict he ever faced with his own church concerned his Calvinist interpretation of Holy Communion.

Galileo also had obvious supporters in the Catholic Church. The comment frequently attributed to him, that “the intention of the Holy Spirit is to teach us how one goes to heaven and not how heaven goes”, was actually attributed by Galileo in his Letter to the Grand Duchess to Cardinal Baronio . It is obvious from other correspondence that Galileo had other supporters within the Catholic Church. However, for whatever reason, the anti-Copernican forces held sway and the Catholic Church held the power in Galileo’s situation when it came to the crunch. It is difficult to enter into the minds of Galileo’s ecclesiastical opponents, but perhaps part of the problem lay in Galileo’s theology, which argued for the right of scientists, not theologians, to interpret the Book of Nature; and thus sounded just a little too Protestant for the Catholic hierarchy amidst the conflicts of the times.

However, there are other very important differences between Kepler and Galileo. Kepler had dispensed with Copernicus’ ideological underpinnings and the theory arising as a result. Gone were the perfect circles and epicycles. In their place, elliptical motions based on Solar gravity. Card-carrying members of Galileo’s fan club assert that his discoveries of the moons of Jupiter and the phases of Venus were the things which advanced the Copernican cause. However, in Galileo’s own hands the moons of Jupiter were presented as proof of the very Copernican epicycles with which Kepler had dispensed. Galileo wrote in Considerations on the Copernican Opinion (1615):

“But if rational arguments were not sufficient to make one understand the necessity of having to place eccentrics and epicycles in nature, at least the senses themselves  would have to persuade him: for we see the four Medicean planets trace four small circles around Jupiter which are very far from enclosing the earth, in short, four epicycles; …” So, to deny eccentrics and epicycles in the motion of the planets is like denying the light of the sun, or else it is to contradict oneself.”

It seems bizarre to us today to imagine that the planets whirl around on little epicycles as they continue their movement around a larger eccentric (or circle displaced from the centre). However, Galileo believed his discovery of Jupiter’s moons had confirmed this behaviour. He was still believing in the epicycles of the planets six years after Kepler had dispensed with them.

Galileo continued to demonstrate his inability to grasp the nature of celestial motion in his theory of the tides. In his Discourse on the Tides (1616), Galileo proposed that the tides were caused by a combination of the inertia of the water as the rotation of the Earth first coincided with, then opposed, its orbital motion around the Sun; and the size of the sea basin in which the water was contained. He regarded this as proof of the motion of the Earth, apparently unable to see that the argument could be used in the opposite way. As if to emphasise his lack of understanding, Galileo rejected Kepler’s correct explanation of the tides and accused Kepler of dabbling in the occult in his explanation.

Galileo’s discovery of the phases of Venus did show that the Sun had a satellite, but it did not prove anything about the motion of the Earth around the Sun.

In short, Galileo’s astronomical observations of Venus and the moons of Jupiter had made him famous, but he does not appear to have had the theoretical insight which Kepler had on matters astronomical; and which would ultimately carry sway.

Conclusion

It should be obvious by now that there are two different stories about the Christian Church and astronomy in the late 16th and early 17th centuries. It is true that in Catholic quarters, an initial warm reception of Copernicus turned into a chilly condemnation – a fact for which the Roman Catholic Church probably remains embarrassed to this day. However, in Protestant circles, Copernican theory was received and developed from an ancient Greek ideology to a scientific theory through Rheticus, Mästlin, and above all, Kepler.

As an astronomer, Kepler outshone Galileo in his understanding of the physical forces from the Sun causing planetary motion, the real nature of that motion, his understanding of the tides and his grasp of how a telescope works. The more we uncover of Kepler’s writings, the greater he appears. Maybe it is time to dispense with the Galileo myth. It has a competitor called the Kepler myth. Rather than Kepler being an icon for science against religion, he is an icon for science with religion. Kepler believed that through his astronomy, God was being revealed. His last professional writing concludes with a prayer, thanking God for the gift of his intellect and the opportunity to use it for science.  If you cannot cope with that, fair enough! But please, do not go dumping the “Galileo myth” on the rest of us either.

Science, Religion and Galileo

Page Views