Religious fanatics would rather burn progressive thinkers like Galileo Galilei on the stake rather than listen to reason.
Galileo didn't really get into trouble for his books, or his scientific convictions, it was his arrogant duplicity. It's true he was called before the Roman Inquisition and charged with the heretical teaching that the earth moves around the sun or otherwise. And he was forced to recant. But he was neither imprisoned nor tortured; he was sentenced to a comfortable house arrest during which he died at age 78.
Long before he became Pope Urban VIII (1623 to 1644), while still a cardinal, Maffeo Barberini knew and liked Galileo. In 1623 when he published Assayer, Galileo dedicated the book to Barberini (the Barberini family crest appeared on the title page of the book), and the new pope was said to have been delighted by the many nasty insults it directed against various Jesuit scholars. Assayer was mainly an attack on Orazio Grassi, a Jesuit mathematician, who had published a study that (correctly) treated comets as small heavenly bodies; Galileo ridiculed this claim, arguing wrongly that comets were but reflections on vapors arising from the earth. In any event, Assayer, prompted Pope Urban VIII to write an adulatory poem on the glory of astronomy. So, what went wrong?
It is important to put the Galielo affair in historical context. At this time the Reformation stood defiant in northern Europe, the Thirty Year's War raged, and the Catholic Counter-Reformation was in full bloom. Partly in response to Protestant charges that the Catholic Church was not faithful to the Bible, the limits of acceptable theology were being narrowed, and this led to increasing Church interference in scholarly and scientific discussions. However, Urban VIII and other leading officials were not ready to clamp down on scientists, but instead proposed ways to avoid any conflicts between science and theology by separating their domains. Thus, Friar Marin Mersenne advised his network of leading scientific correspondents to defend their studies on grounds that God was free to place the earth anywhere he liked, and it was the duty of scientists to find out where he had put it. More cautious early scientists adopted the tactic of identifying scientific conclusions as hypothetical or mathematical, hence being without direct theological implications. And that was what the pope asked Galileo to do - to acknowledge in his publications that "definitive conclusions could not be reached in the natural sciences. God in his omnipotence could produce a natural phenomenon in any number of ways and it therefore was presumptuous for any philosopher to claim that he had determined a unique solution.
That seemed an easy evasion. And, given Galileo's propensity to claim false credit for inventions made by others, such as the telescope, and to have conducted empirical research he probably did not really perform, such as dropping weights from the Leaning Tower of Pisa, it would not seem to have stretched his ethical standards to have gone along with the pope. But to defy the pope in a rather offensive way was quite consistent with Galileo's ego.
In 1632, Galileo published his awaited Dialogue Concerning the Two Chief World Systems. Although the ostensible purpose of the books was to present and explanation of tidal phenomena, the two systems involved were Ptolemy's, in which the sun circles the earth, and Copernicus's wherein the earth circles the sun. The dialog involves three speakers, two of them philosophers and the third a layman. It is the layman, Simplicio, who presents the traditional views in support of Ptolemy - the resemblance of the name to "simpleton" was obvious to all. This allowed Galileo to exploit the traditional "straw man" technique to ridicule his opponents. Although Galileo did include the disclaimer suggested by the pope, he put it in the mouth of Simplicio, thereby disowning it.
The book caused an immense stir and, understandably, the pope felt betrayed - although Galileo never seemed ot have grasped that fact and continued to blame the Jesuits and university professors for his troubles. Despite that, the pope used his power to protect Galileo from any serious punishment. Unfortunately, Galileo's defiant action stimulated a general crackdown by the Counter-Reformation Church on the intellectual freedom that otherwise may never have occurred. Ironically, much that Galileo presented in the book as correct science was not; his theory of the tides, for example, was nonsense, as Albert Einstein pointed out in his foreword to a 1953 translation of Galileo's notorious book. Equally ironic is the fact that the judgment against Galileo was party motivated by efforts on the part of the Church leaders to suppress astrologers - some theologians mistakenly equating the claim that the earth moved with the doctricts that fate was ruled by the motion of heavenly bodies. This demonstrates that powerful groups and organizations often will abuse their power to impose their beliefs, a shortcoming that certainly is not limited to religious organizations - the Communist regime in the Soviet Union outlawed Mendelian genetics on grounds that all characteristics are caused by the environment. But it also shows that Galileo was not some naive shcolar who fell victim to a bunch of ignorant bigots - these same "bigots" ignored dozens of other prominent scientists, many of them resident in Italy. For all his posturing Galileo remained deeply religious. Had he been any less devout he would have refused to go to Rome when summoned by the Inquisition; Venice offered him asylum.
Roger Bacon, requested by Pope Clement IV, to write for him. He wrote the Opus Majus in one year, also available in a modern edition (1996 pages) covers all aspects of natural science. Covering knowledge of many different fields: mathematics; the size and position of heavenly bodies; the physiology of eyesight; optics, including refraction, mirrors, and lenses, the magnifying glass, and spectacles; recipe for gunpowder, calendar reform etc. The Opus Majus was filled with remarkable predictions about future inventions including microscopes, telescopes, and flying machines.
Bacon stressed empiricism as opposed to authority. "Authority has no savior, unless reason for it is given, and it does not give understanding, but belief. For we believe on the strength of authority, but we do not understand through it. Nor can we distinguish between sophism and demonstration, unless we know to test the conclusion by works, as I will show later in the experimental sciences." Theories must be put to a test for them to be valid. which was a departure from the Greeks as well as from early Christian thinkers who all believed in the superiority of ideas and abstract forms to empirical reality and concluded that reason, not observation, was always the true test of any philosophical claim. It followed that to make an experimental or observational test of an idea was to accept the superiority of the imperfect to the perfect. That was the powerful tradition that proponents of experimentalism had to overcome. Only because Bacon, Grosseteste, and other Scholastics fought and won the battle for empiricism was it possible for the rise of science to occur.
Copernicus. All of the prior theorizing was well known to Copernicus since it was taught at all three of the Italian universities he attended. So what did Copernicus contribute? He put the sun in the middle of the solar system and had the earth circling it as one of the planets. What gave such special luster to his work was that he expressed it all in mathematics and worked out the geometry of his system so as to permit the calculation of future positions of the bodies involved, which was essential for setting the dates of Easter, the solstices, and the like. However, these calculations were no more accurate or any easier to calculate than those based on the prior Ptolemaic system dating from the second century CE, because Copernicus failed to realize that the orbits in the solar system were elliptical, not circular. Therefore, to make his system work, Copernicus had to postulate that there were loops in the orbits of the heavenly bodies that delayed them sufficiently so they did not complete their obits too soon - it would not do for the earth to circle the sun in only three hundred days. However, these loops lacked any observational support; had they existed, a heavenly body should have been observed looping. Consequently, everything in Copernicus's famous book, On the Revolutions of the Heavenly Spheres, is wrong, other than the placement of the sun in the center. It was nearly a century later that Johannes Kepler, a German Protestant, got things right by substituting ellipses for Copernicus's circles. Now each heavenly body was always where it was supposed to be, was on time, and required no loops.
Of course even with Kepler's additions, there was still no explanation of why the solar system functioned as it did, or of why, for example, bodies remained n their obits rather than flying off into space. The achievement of such an explanation awaited Isaac Newton, who famously remarked, "If I have seen further it is by standing on the shoulders of giants." But over several prior centuries, many essential pieces of such a theory had been assembled: that the universe was a vacuum; that no pushers were needed because once in motion, the heavenly bodies would continue in motion; that the earth turned; that the sun was the center of the solar system; that the orbits were elliptical. The record of systematic progress is why the distinguished historian of science, I. Bernard Cohen (1914-2003) noted that "the idea that a Copernican revolution in science occurred goes counter to the evidence ... and is the invention of later historians." Most of Cohen's sophisticated colleagues agree. Copernicus added a small step forward in a long process of normal science. It should be noted that the scholars involved in this long process were not rebel secularists. Not only were they devout Christians, they were priests or monks, and four of them were bishops and one was a cardinal. Science did not suddenly erupt in a great intellectual revolution during Newton's time, this era of superb achievements was the culmination of centuries of sustained, normal scientific progress. The Scientific Revolution was invented to discredit the medieval Church by claiming that science burst forth in full bloom (thus owing no debts to prior Scholastic scholars) only when a weakened Christianity no longer could suppress it.
The great scientific achievements of the sixteenth and seventeenth centuries were produced by a group of scholars notable for their piety, who were based in Christian universities, and whose brilliant achievements were carefully built upon an invaluable legacy of centuries of brilliant Scholastic Scholarship. Since the start of the so-called Scientific Revolution is usually attributed to Nicolaus Copernicus, it is appropriate to examine his intellectual predecessors to demonstrate that this was a work of normal science. He wasn't some obscure Pole, he received a superb education at the best Italian universities of the time: Bologna, Padua, and Ferrara. The idea that the earth circled the sun did not come to him out of the blue; he was taught the essential fundamentals leading to the heliocentric model of the solar system by his Scholastic professors. What Copernicus added was not a leap but was the implicit next step in a long line of discovery and innovation stretching back for centuries. Robert Grosseteste (1168-1253), Albertus Magnus (1200-1280) (so celebrated during his time his colleagues, including Roger Bacon, began to add the title "Magnus" (the great) to their names, Roger Bacon (1214-94), William of Ockham (1295-1349), Nicole D'Orseme (1325-82), Nicolas of Cusa (1401-64), Nicolaus Copernicus (1473-1543), there are more but these are sufficient to research further.
