Reply To: Who, alive today, can answer questions like R Aryeh Kaplan?

I also forgot to add Rav Moshe Meiselman from Yeshivas Toras Moshe in Jerusalem. Not only is he a Talmud Chacham, but he is also one of the largest challengers against Rabbi Natan Slifkin. I heard he is coming out with a new book that specifically challenges statements made by Rabbi Slifkin.