They have e-mail now in Purgatory …
Galileo had the misfortune to become a poster boy for a cause he would never have espoused himself; he was a devout Catholic and all three of his children adopted the religious life.*
He honestly believed that Copernicus was right at a time when it was impossible to prove that and the Church had not made up its mind (on a question with which it should never have gotten involved).** Churchmen (and he hobnobbed with them) wanted him to keep quiet, but he wouldn’t.
Canadian literary journalist Wade Rowland offers some background:
As a man of no small ego, and a touch paranoid to boot, he would doubtless enjoy of the veneration in which he is held as astronomer and martyr to reason and science, victim of religious dogmatism and anti-intellectualism. But he would be greatly disturbed by the simple-minded version of his travails that has come down to us through three and a half centuries of myth-making and propaganda. He would want to insist that his argument with the Church was of far, far greater significance than a squabble over whether or not the earth moves, as most of us now suppose it was. The Copernican question had in fact been largely settled in the minds of the better informed Church leaders, including the pope and his chief theologian – not to mention the brilliant Jesuit mathematicians and astronomers of the Collegeo Romano – long before Galileo’s epic confrontation with Rome came to a head.
In the matter of his notorious trial by the Holy Office in 1633, he conceded his error and publicly – and sincerely – demonstrated his contrition. He had, as the Church charged, no conclusive grounds for claiming that the Copernican hypothesis was fact, and it had been a matter of serious insubordination for him to disobey a direct papal order not to go about behaving as if he did. As a deeply committed Catholic and the beneficiary of ecclesiastical favours, he was, after all, obliged to play by the rules. But to this day his admirers stubbornly refuse to accept him at his word, preferring in a bizarre twist of logic to see him as a moral weakling, cowed by threats of the rack, or, worse, a liar and perjurer who falsely confessed before God in order to save his mortal skin.
He was none of these things. (Nor, as he knew, were threats of torture more than an antiquated procedural formality – no threat at all.) He was a man captivated by his discovery that laws of mechanical motion could be derived from direct observation of the world, and then expressed in elegant mathematical formulae. The scales had fallen from his eyes and he could see with ecstatic clarity that the world was in some very real way composed of number. More.
That wasn’t, in isolation, untrue either. But he was willing to throw other equally important truths under the stoneboat, and it was by no means only religious dogmatists who opposed him. The essay is a breath of fresh air, as is Dava Sobel’s Galileo’s Daughter.
*Dava Sobel’s biography recounts that they were born out of wedlock (Galileo could not marry their mother due to class differences, which functioned in his day somewhat like castes, or so Dava Sobel tells us.) The religious life provided a respectable exit from the problem, but that should not be taken to mean that the family lacked piety. Quite the reverse.
** Which may be one reason it stays out of age-of–the-Earth conflicts today.