Art censorship, especially in cases that did not involve printed books,
    also once again reveals the limitations and often fortuitous nature of the
    whole Index project. Condemnations were often delayed for years or even
    centuries, or omitted altogether, as censors struggled to keep up with the
    constant flow of publication and creative works. They instead targeted
    individuals on a selective and often somewhat random basis, according to
    what came to their attention. Montaigne was quite dismayed by the close
    expert scrutiny his Essais received on his arrival in Rome, and it must
    also have been a hawk-eyed reader indeed who managed to pick out a single
    offending passage in the hundreds of pages of Cervantes’s Don Quixote. 
 – Robin Vose, The Index of Forbidden Books: Four Centuries of Struggle Over
    Word and Image For the Glory of God.
Alas, the history outlined in Robin Vose’s harrowing new study of
    institutionalized intolerance, The Index of Forbidden Books (Reaktion
    Books, distributed by University of Chicago Press), often veered all the
    way to the extreme right and even included, on special occasion, bonfires
    built to incinerate ideas which were deemed too dangerous, or sometimes
    just too alternative to orthodoxy, to be permitted on the open market of
    human consciousness. You can imagine how afraid the powers that be must
    have been around the turn of the first millennium, when the paranoid forces
    of paralyzing superstition were simply not enough and they needed to resort
    to more stringent methods of control, such as the complete non-existence of
    alternate perceptions of reality that ran counter to their own strategic
    plan for managing moral behaviours and belief systems. The one key
    ingredient they never quite clarified or explained, of course, was just why
    the supreme Deity they worshipped, and whose psychic persona armor they
    were obsessed with forcing down the throats of the entire population of the
    world, would ever need to be “glorified” in so crass a manner.