A striking example of this occurred recently during debates I've had with apologists who point out that Charles Darwin's books were never put onto the Index, and claim that this is one of many things which proves that the Catholic Church is the greatest supporter of science of all time. The obvious, forest-for-the-trees answer to that is that THERE WAS SUCH A THING AS THE INDEX, from the 16th century to the 20th. Here's a webpage listing every author who was ever on the Index. That webpage is a little misleading: it claims to be the Index in 1949. Actually, many authors were put on the Index and then later taken off. I happen to have a copy of the official Index as it stood in 1854. Charles Darwin was never on the Index, but in 1854, when Charles turned 45 years old, his father, the eminent, world-famous biologist Erasmus Darwin, was on the Index. (Yes, Charles' very own Dad. No one can speak for Charles now, but is it really very far-fetched to imagine that Charles might have gotten just a little bit annoyed if someone tried to tell him that an organization which had banned his father's books was the greatest promoter of science of all time?) So were Bruno (opera omnia, of course: the complete works), Descartes, Spinoza, Leibniz, Kant, and, oh yes, also... Wait for it... Francis Bacon! ("We're the greatest supporters of science of all time! Don't read Francis Bacon, generally credited with the formulation of the scientific method, often called the 'father of modern science,' or you'll go to Hell!") And of course also Pascal and Diderot and Voltaire and Luther and Hume (opera omnia) and Bentham and Locke and Heine, and so many other illustrious writers that it is no exaggeration to say that it was a bit of an insult to an illustrious modern European writer if he or she were not put onto the Index. It is a Who's Who of the intellectual community of Europe. (Why not Charles Darwin? Why not Goethe or Feuerbach or Schopenhauer or Marx or Nietzsche? Didn't each of them deserve that distinction as much as Zola [opera omnia.]? Maybe because the people composing the Index rightly suspected that such authors would only be overjoyed and encouraged by being Indexed. Maybe because there's not much rhyme or reason here.) Over 400 pages long, the Index in 1854. Several thousand entries.
People who actually promote science don't ban books they dislike. It would never occur to them to do such a thing. They say: this book is terrible. Go ahead, read it for yourself and you'll see what I mean.