In regard to their history, there are two main points to be considered. It is in the first place constantly assumed, especially at the present day, that the opposition which Copernicanism encountered at the hands of ecclesiastical authority was prompted by hatred of science and a desire to keep the minds of men in the darkness of ignorance. To suppose that any body of men could deliberately adopt such a course is ridiculous, especially a body which, with whatever defects of method, had for so long been the only one which concerned itself with science at all.If you wade through that (sorry; New Advent is not known for brevity!), the first thing that stands out to me is that this happened after the Protestant Reformation. That is not a small point, and if you like your history dramatized, look to the film "Elizabeth" for some idea of how seriously the Catholic church took its claims to English souls (and property; Henry's crimes included not just leading people astray, but taking all the ecclesiastical property and giving it to his friends). The film nicely dramatizes the politics and violence that Henry's break with Rome produced. My point being not to praise a movie, or declare it a documentary, but to point out how politically treacherous the post-Reformation era was in Europe, as people drew up sides and decided who was in, who was out (a recent biography of Shakespeare points out his parents may have been Catholic, but hid their beliefs in order not to run afoul of Good Queen Bess; to be Catholic in England in the 17th century was to be a traitor to the Crown. You don't get much more political than that.)
It is likewise contradicted by the history of the very controversy with which we are now concerned. According to a popular notion the point, upon which beyond all others churchmen were determined to insist, was the geocentric system of astronomy. Nevertheless it was a churchman, Nicholas Copernicus, who first advanced the contrary doctrine that the sun and not the earth is the centre of our system, round which our planet revolves, rotating on its own axis. His great work, "De Revolutionibus orbium coelestium", was published at the earnest solicitation of two distinguished churchmen, Cardinal Schömberg and Tiedemann Giese, Bishop of Culm. It was dedicated by permission to Pope Paul III in order, as Copernicus explained, that it might be thus protected from the attacks which it was sure to encounter on the part of the "mathematicians" (i.e. philosophers) for its apparent contradiction of the evidence of our senses, and even of common sense. He added that he made no account of objections which might be brought by ignorant wiseacres on Scriptural grounds. Indeed, for nearly three quarters of a century no such difficulties were raised on the Catholic side, although Luther and Melanchthon condemned the work of Copernicus in unmeasured terms. Neither Paul III, nor any of the nine popes who followed him, nor the Roman Congregations raised any alarm, and, as has been seen, Galileo himself in 1597, speaking of the risks he might run by an advocacy of Copernicanism, mentioned ridicule only and said nothing of persecution. Even when he had made his famous discoveries, no change occurred in this respect. On the contrary, coming to Rome in 1611, he was received in triumph; all the world, clerical and lay, flocked to see him, and, setting up his telescope in the Quirinal Garden belonging to Cardinal Bandim, he exhibited the sunspots and other objects to an admiring throng.It was not until four years later that trouble arose, the ecclesiastical authorities taking alarm at the persistence with which Galileo proclaimed the truth of the Copernican doctrine. That their opposition was grounded, as is constantly assumed, upon a fear lest men should be enlightened by the diffusion of scientific truth, it is obviously absurd to maintain. On the contrary, they were firmly convinced, with Bacon and others, that the new teaching was radically false and unscientific, while it is now truly admitted that Galileo himself had no sufficient proof of what he so vehemently advocated, and Professor Huxley after examining the case avowed his opinion that the opponents of Galileo "had rather the best of it". But what, more than all, raised alarm was anxiety for the credit of Holy Scripture, the letter of which was then universally believed to be the supreme authority in matters of science, as in all others. When therefore it spoke of the sun staying his course at the prayer of Joshua, or the earth as being ever immovable, it was assumed that the doctrine of Copernicus and Galileo was anti-Scriptural; and therefore heretical. It is evident that, since the days of Copernicus himself, the Reformation controversy had done much to attach suspicion to novel interpretations of the Bible, which was not lessened by the endeavours of Galileo and his ally Foscarini to find positive arguments for Copernicanism in the inspired volume. Foscarini, a Carmelite friar of noble lineage, who had twice ruled Calabria as provincial, and had considerable reputation as a preacher and theologian, threw himself with more zeal than discretion into the controversy, as when he sought to find an argument for Copernicanism in the seven-branched candlestick of the Old Law. Above all, he excited alarm by publishing works on the subject in the vernacular, and thus spreading the new doctrine, which was startling even for the learned, amongst the masses who were incapable of forming any sound judgment concerning it. There was at the time an active sceptical party in Italy, which aimed at the overthrow of all religion, and, as Sir David Brewster acknowledges (Martyrs of Science), there is no doubt that this party lent Galileo all its support.
In these circumstances, Galileo, hearing that some had denounced his doctrine as anti-Scriptural, presented himself at Rome in December, 1615, and was courteously received. He was presently interrogated before the Inquisition, which after consultation declared the system he upheld to be scientifically false, and anti-Scriptural or heretical, and that he must renounce it. This he obediently did, promising to teach it no more. Then followed a decree of the Congregation of the Index dated 5 March 1616, prohibiting various heretical works to which were added any advocating the Copernican system. In this decree no mention is made of Galileo, or of any of his works. Neither is the name of the pope introduced, though there is no doubt that he fully approved the decision, having presided at the session of the Inquisition, wherein the matter was discussed and decided. In thus acting, it is undeniable that the ecclesiastical authorities committed a grave and deplorable error, and sanctioned an altogether false principle as to the proper use of Scripture. Galileo and Foscarini rightly urged that the Bible is intended to teach men to go to heaven, not how the heavens go. At the same time, it must not be forgotten that, while there was as yet no sufficient proof of the Copernican system, no objection was made to its being taught as an hypothesis which explained all phenomena in a simpler manner than the Ptolemaic, and might for all practical purposes be adopted by astronomers. What was objected to was the assertion that Copernicanism was in fact true, "which appears to contradict Scripture". It is clear, moreover, that the authors of the judgment themselves did not consider it to be absolutely final and irreversible, for Cardinal Bellarmine, the most influential member of the Sacred College, writing to Foscarini, after urging that he and Galileo should be content to show that their system explains all celestial phenomena — an unexceptional proposition, and one sufficient for all practical purposes — but should not categorically assert what seemed to contradict the Bible, thus continued:
I say that if a real proof be found that the sun is fixed and does not revolve round the earth, but the earth round the sun, then it will be necessary, very carefully, to proceed to the explanation of the passages of Scripture which appear to be contrary, and we should rather say that we have misunderstood these than pronounce that to be false which is demonstrated.
By this decree the work of Copernicus was for the first time prohibited, as well as the "Epitome" of Kepler, but in each instance only donec corrigatur, the corrections prescribed being such as were necessary to exhibit the Copernican system as an hypothesis, not as an established fact. We learn further that with permission these works might be read in their entirety, by "the learned and skilful in the science" (Remus to Kepler). Galileo seems, says von Gebler, to have treated the decree of the Inquisition pretty coolly, speaking with satisfaction of the trifling changes prescribed in the work of Copernicus. He left Rome, however, with the evident intention of violating the promise extracted from him, and, while he pursued unmolested his searches in other branches of science, he lost no opportunity of manifesting his contempt for the astronomical system which he had promised to embrace. Nevertheless, when in 1624 he again visited Rome, he met with what is rightly described as "a noble and generous reception". The pope now reigning, Urban VIII, had, as Cardinal Barberini, been his friend and had opposed his condemnation in 1616. He conferred on his visitor a pension, to which as a foreigner in Rome Galileo had no claim, and which, says Brewster, must be regarded as an endowment of Science itself. But to Galileo's disappointment Urban would not annul the former judgment of the Inquisition.
After his return to Florence, Galileo set himself to compose the work which revived and aggravated all former animosities, namely a dialogue in which a Ptolemist is utterly routed and confounded by two Copernicans. This was published in 1632, and, being plainly inconsistent with his former promise, was taken by the Roman authorities as a direct challenge. He was therefore again cited before the Inquisition, and again failed to display the courage of his opinions, declaring that since his former trial in 1616 he had never held the Copernican theory. Such a declaration, naturally was not taken very seriously, and in spite of it he was condemned as "vehemently suspected of heresy" to incarceration at the pleasure of the tribunal and to recite the Seven Penitential Psalms once a week for three years.
Under the sentence of imprisonment Galileo remained till his death in 1642. It is, however, untrue to speak of him as in any proper sense a "prisoner". As his Protestant biographer, von Gebler, tells us, "One glance at the truest historical source for the famous trial, would convince any one that Galileo spent altogether twenty-two days in the buildings of the Holy Office (i.e. the Inquisition), and even then not in a prison cell with barred windows, but in the handsome and commodious apartment of an official of the Inquisition." For the rest, he was allowed to use as his places of confinement the houses of friends, always comfortable and usually luxurious. It is wholly untrue that he was — as is constantly stated — either tortured or blinded by his persecutors — though in 1637, five years before his death, he became totally blind — or that he was refused burial in consecrated ground. On the contrary, although the pope (Urban VIII) did not allow a monument to be erected over his tomb, he sent his special blessing to the dying man, who was interred not only in consecrated ground, but within the church of Santa Croce at Florence.
Finally, the famous "E pur si muove", supposed to have been uttered by Galileo, as he rose from his knees after renouncing the motion of the earth, is an acknowledged fiction, of which no mention can be found till more than a century after his death, which took place 8 January 1642, the year in which Newton was born.
This isn't to justify the reaction of the Church to Galileo, but to examine it a bit more carefully. Similarities to Creationists and fundamentalists in general may be made, but only glancingly. Rome in 17th century Europe had real political and military power. Ken Ham may have the power to persuade states to include Creationism in public school curricula, but he lacks the power to imprison scientists or contain ideas. And, given that today, not quite 400 years later, about 1/4th of the people in "First World" countries still admit to geocentrism when it comes to the solar system, the fear of the church in the 17th century that "the masses...were incapable of forming any sound judgment concerning" Galileo's assertions is not an entirely unreasonable one. Unless you're going to argue the people of 17th century Europe were far more enlightened than the people of 21st century Europe.
I'd prefer to argue they were no worse.
There was clearly an attempt, at the time, to assert the supremacy of Scripture, but that was a point upheld by Luther and Melanchthon as well. It was misguided, but it was the 17th century, and the very foundations of Church authority were being challenged; not so much by Galileo as by Luther and Calvin and Zwingli, and people like that "active sceptical party in Italy." And Luther and Calvin were trying to establish their own authority, not to release authority altogether. The reaction to Galileo was not to behead him or torture him or excommunicate him, but simply to gain control over a fractious problem. Galileo, in other words, was within the Church's reach (as he acknowledged by going to Rome. He probably could have joined Luther in Germany; except Luther probably wouldn't have helped him.). And the problem the Church faced was one of order, and of control.
Which is where Creationism treads now: it wants to recover the social control the Church once had, and had through Protestantism, not just before the Reformation. The real desire of Ken Ham is to recover a past that never existed. The Roman church was trying to stop a changing world; Creationists want to turn that entire world back; back to a world that never was. Try as they might to do that, they have no chance of success, or even of a minor victory. I don't even think it's a real threat to scientific inquiry. It isn't science. It's so internally contradictory that to espouse it, you have to be as committed to the fundamentalist literal view of the Bible as Ken Ham is. And that's not a matter of "compartmentalization;" that's a matter of adherence to a worldview only a tiny percentage of people are ever going to accept.
So is there a lesson in the story of Galileo? Only a lesson in the complexity of reason; that reason is not positivism or empiricism or unitary and reducible to one result which excludes all others.
And that history is never just one story we can easily tell to children.