Which Alice?

Introduction
In the volume you now hold, Alice and her friends are back again
for a puzzle romp behind the Looking-Glass that will please
Carrollians as much as the first book of chess puzzles pleased Baker
Street Irregulars. Ray has done it again. His characters not only talk
and behave exactly like the originals, but the book also swarms with
typically Carrollian word play, logic and metalogic problems, and
dark philosophical paradoxes. In Carroll's nonsense world there
were two Alices: the imaginary one and his real-life child-friend
Alice Liddell. In Ray's nonsense world there are also two Alices: a
friend of Ray's, and the imaginary Alice of his first book. Carroll
would have loved them both. And he would have been delighted by
Ray's looking-glass package that unwraps itself only when you try to
wrap it, and a hundred other whimsies that Carroll might have
thought of himself if he had been capable of dreaming up
Raymond Smullyan.
As always in Ray's books, curious metaphysical questions have a
way of catching you by surprise. For example, when Humpty
Dumpty tells Alice she should think of everything, Alice sensibly
declares this to be impossible.
"I never said you could," Humpty replies. "I merely said you
should."
"But is it reasonable to say that I should do something that I
cannot do?"
"That is an interesting problem in Moral Philosophy," answers
Humpty, "but that would take us too far afield."
It would indeed! Ray does not tell you, but Humpty has raised a
famous problem known as Hintikka's paradox, after Jaako Hintikka,
a leader of a fashionable new school of "possible worlds"
philosophers. Is it proper to call morally wrong something a person
cannot do? Hintikka has a notorious argument designed to show it
is wrong to try to do something impossible. There is now a large
literature on this strange question, which belongs to a type of modal
logic called deontic logic. We learned from Carroll that Humpty is
an expert on classical logic and semantics. Now we learn from Ray
that the egg is also an expert on modal logic!
A page or two later, Humpty bewilders Alice with an amazing
one-sentence version of another famous paradox that goes under
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