Rav Kaminetsky (Emes L’Yaakov Shemos 7:22) And the Egyptian magicians did the same with their spellsConcerning the question why are there are no true magicians today or demons or spirits (dybuk) that our ancestors told us about? Similarly there are many types of knowledge that we don’t have or know about. The answer seems to me that this is the result of a case of measure for measure that G-d arranged to ensure that we have free-will and not err. That is why as explained by the Ramban (Shemos 14:21) G-d had a strong wind blowing during the Splitting of the Sea so the Egyptians could err and say it was happening because of the wind and therefore they could also cross the sea as the Jews had. Consequently when there were prophets who performed miracles to persuade them to do G-d’s will, if they didn’t also have real magicians who could do these miracles then they would have had no free-will like what happened to Pharaoh. Even though with the plague of lice the magicians acknowledged that it was the finger of G-d. Pharaoh said in his heart that was because the magicians were lying in order to conceal that Moshe was a greater magician than they. Therefore as long as there was prophecy there needed to be real magic. Afterwards since they still had bas Kol there were also invisible spiritual forces like demons. As long as there were people who could do amazing signs and wonders there were demons which were manifestations of hidden dark spiritual powers.
However later when no one was able to do miracles and everything was purely material and only intellect and desire were involved that is why our Sages have stated that no one as great as Moshe will ever occur again. amongst the Jews though it is possible amongst the Babylonians, it is possible to have someone like Bilaam. In order to allow free-will, That is why in the time of Moshe it was necessary to have Bilaam. This is a general rule This explains why Yosef responded to Pharoh when he said “I heard that you interpret dreams.” By saying it is not his knowledge but rather G-d’s concern for Pharoh’s welfare Similarly with Daniel, Nevuchadnezer said to Daniel “can you tell me what my dream means?” Daniel answered that the meaning is not obtained with esoteric knowledge since only G-d can reveal it, Daniel was thus denigrating this esoteric knowledge which had created a barricade between man and G-d’s providence. This is expressed by the statement that these esoteric arts were considered the epitome of knowledge and understanding in the eyes of non-Jews,
However according to what I have written it is possible that
the Rambam believed that in the time of
the gemora since there were Amoraim who had the power to resurrect the dead and
perform other miracles therefore of necessity it was needed to have the dark
spiritual powers such as demons – in order to have a balance for
free-will. So therefore only in modern
times when true spiritual powers are hidden will will there be a corresponding
concealment of the dark forces such as
demons
And I remember that when I was in Kelm, that Rav Ekchonon Wasserman wrote in the name of the
Chofetz Chaim “that the famous event of a dybuk that occurred in his lifetime
was likely the last appearance of this type. That was because that to the
degree the power of Torah and true spirituality is reduced the power of the dark
forces of impurity are likewise reduced.”
However it is possible that even today that in the places
where there are still Jews with pure
faith and act properly that they also have an extra measure of the dark
spiritual forces – in order to maintain a proper balance. Think about this
deeply!