I “owe” getting back to Tosfos and the Rambam (previous post) on psak and hashkafa but haven’t had time to fully develop an approach, so I’m going to tackle things piecemeal. I want to start with a few comments on a point Dr. Marc Shapiro makes in an essay printed on the seforim blog in response to a review of his book, specifically his point #7. I do not want to make my post excessively long by quoting it in its entirety, so ayen sham.
Shaprio approvingly quotes Prof. Menachem Kellner, “Dogmas, it must be recalled, are beliefs taught as true by the Torah; is the truth taught by the Torah historically conditioned?” I don’t get it, and this seems to be a crucial point in their argument. To take one possible example: R’ Eliezer believed that the assertion that machshiri milah are doche shabbos was a Torah truth, and undoubtedly this was the halacha as practiced in his community. Today, we assume machshirei milah are not doche Shabbos. Why is Kellner not troubled in this case by halacha being “historically conditioned”? Why is he not troubled that the entire community under the leadership of R’ Eliezer may be classified as mechalilei Shabbos based on our definition of Torah truth?
A more radical example of "historical conditioning" is the recent daf yomi (Yevamos 77) regarding the debate over generations whether the derasha of “amoni v’lo amonis, moavi v’lo amonis” was true. Until Chazal determined that this halacha was rooted in a kabalah, there was room for the Bais Din of each generation to rule differently on the issue. Thus (as the Brisker Rav explains) Ploni Almoni did not question Boaz’s psak that Rus was a kosher convert, but he worried about whether a later B”D would overturn that psak and declare his grandchildren to be goyim.
In his review of Shapiro’s book, Kellner writes that Ikkarim cannot be decided as other psak halacha is because it leads to “weird” conclusions, “the weirdest of which is the idea that holding a certain belief at one time time could cause one to be excluded from the community of Israel and to lose his or her share in the world to come, while holding that belief at another time carries with it no such consequences.” Perhaps I am missing something, but I really don’t understand why that is any weirder than someone who is Sabbath observant by R’ Eliezer’s standards being considered chayav kareis (i.e. their soul cut off from Heaven) if they perform the same action in a different locale, or why it is any weirder than Rus being considered Jewish at one point in time and perhaps being labeled a goya in a different historical period. Ain lecha “exclusion from the community of Israel” gedola m’zu! Why is dogma in a different category than these questions?