The Limbus of Fools, or Fool's Paradise. As fools are not responsible for their works, they are not punished in Purgatory, but cannot be received into Heaven; se they go to a place called the Paradise of Fools.
Then might you see Cowls, hoods, and habits, with their wearers tossed And fluttered into rags; then relics, beads, Indulgences, dispenses, pardons, bulls, The sport of winds. All these, upwhirled aloft, Into a Limbo large and broad, since called The Paradise of Fools.
One cannot wonder that Milton's great poem was placed by the Catholics in the Index of books forbidden.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894