I agree with your interpretation, Eric, and that's also what I get out of the letter I quoted above re: Shelley.
Although as it happens, Shelley was expelled from University College, Oxford, for disseminating a tract he wrote called "They Necessity of Atheism", by which he actually meant Deism.
Edit; we've been talking a lot lately about the Areopagus in Athens and it's relationship with Parrhesia, candor or frank speech. John Milton chose it for the title of his own tract, a defense of free expression called Areopagitica.