Galileo's Dialogue Concerning the Two Chief World Systems opens with a seemingly sarcastic "Note to the discerning reader", beginning:
Several years ago there was published in Rome a salutary edict which, in order to obviate the dangerous tendencies of our present age, imposed a seasonable silence upon the Pythagorean opinion that the earth moves There were those who impudently asserted that this decree had its origin not injudicious inquire, but in passion none too well informed Complaints were to be heard that advisers who were totally unskilled at astronomical observations ought not to clip the wings of reflective intellects by means of rash prohibitions.
Upon hearing such carping insolence, my zeal could not be contained. Being thoroughly informed about that prudent determination, I decided to appear openly in the theater of the world as a witness of the sober truth. I was at that time in Rome; I was not only received by the most eminent prelates of that Court, but had their applause; indeed this decree was not published without some previous notice of it having been given to me. Therefore I propose in the present work to show to foreign nations that as much is understood of this matter in Italy, and particularly in Rome, as transalpine diligence can ever have imagined Collecting all the reflections thai properly concern the Copernican system, I shall make it known that everything was brought before the attention of the Roman censorship, and that there proceed from this clime not only dogmas for the welfare of the soul, but ingenious discoveries for the delight of the mind as well.
I can't quite tell how sarcastic Galileo is being here - in the first paragraph he seems to be facetiously praising the Vatican, but in the second he seems to drops the irony and state his opinions directly. More importantly though, I don't actually have a clear picture what events from "several years ago" he's referring to. Can someone clarify precisely what story this all fits into, and maybe assess the level of irony in Galileo's tone?