The Ghost

Hamlet is discussed in Asimov's Guide to Shakespeare, where the good
doctor offers a few words on the Ghost: It is important, even crucial, to
think of the Ghost not as we think of ghosts generally, but as the men of
Shakespeare's time thought of them.
Hence, the Ghost is a spirit that can take on
any shape for any purpose. The most that can be said is that it looks
like Hamlet's father, that it has taken on the shape of Hamlet's father.

What it really is, no one can say. He (Asimov) goes on to repeatedly point out
the differences between the perceptions of the original audience and the
modern ones in a number of particulars:

1. The Elizabethan audience would therefore well understand that a king's
brother might succeed to the throne to the exclusion of the king's son.

2. They would also understand quite well, without being told, that the
son would be in mortal danger.

3. The Elizabethan audience, much more accustomed to the intrigues of
royal succession than we are, might be expected to catch on to this sort
of thing [maneuvers by Polonius] as a matter of course.

4. Hamlet is the natural opponent of the succession and if he continues
to wear mourning it is clear enough that he feels there is no joy in the
King. It amounts almost to a claim for the throne on his own behalf. All
of this would be plain to Claudius and to the Elizabethan audience (wise
in the ways of disputed succession) as well.

5. This [Hamlet's lack of freedom in marriage] is a careful explanation
of something Ophelia ought surely to understand, and of something, for
that matter, that the Elizabethan audience could well take for granted.

This is quite a list, and I don't believe many would object to it.

However, once we start throwing in conjectures about what the original
audience might have expected in other ways, ways relating to their
religious beliefs (if any), all of a sudden there is a lot of yakking and
squawking. Perhaps that is natural, since we now live in a place and time
where Enlightenment Philosophy is dominant, especially (although not
exclusively) among the educated, and Enlightenment Philosophy and that
which it has largely replaced (a Christian theory of reality) are
completely incompatible. One might almost go so far as to claim they are
serious enemies (if they were to be personified).

In his interesting book The Medieval Theatre, the author, Glynne Wickham,
made a number of observations about that theater which might be applied to
later Elizabethan drama also, particularly Hamlet. He writes,

I would not wish to deny that each and all of these extensions of
dramatic possibilities brought the drama into ever closer touch with
secular life but I must equally insist that this traffic also flowed the
other way, bringing ever more aspects of secular life as imitated in
dramatic games firmly into the patterns prescribed by the controlling hand
of the universal Church throughout the length and width of Christendom.
Thus, even in the case of the most satirical of farces and Interludes of
the fifteenth century and the early sixteenth, the ethic informing their
structure and moral conclusion was firmly Christian. (p. 181)

Any thoughts on any of the above suppositions?