Rabbi Yossi Prevails (article summary)

My article this past Shabbos in the Jewish Link was about the phrase “Rabbi Yossi Nimuko Imo” as a reason to rule like him when he argues against a single colleague, or even against multiple colleagues. See it in HTML, flipdocs, and on Substack (with more hyperlinks).

Here is a brief summary.

1. Local explanation of the sugya — the Mishnah with Rabbi Yehuda and Rabbi Meir, each with different ways of becoming a muad / reverting to tam. Rabbi Yossi and Rabbi Shimon, contemporaries of the first two, each taking one from Rabbi Yehuda and one from Rabbi Meir, so that all four permutations exist.
   
   Rav Nachman citing his father-in-law / teacher Rabba bar Avuah of ruling effectively like Rabbi Yossi. But presenting it almost like each position in the Mishnah, of Rabbi Meir or of Rabbi Yehuda in becoming tam / becoming muad, we rule like that since Rabbi Yossi agrees. This sounds like saying that there is a majority endorsing that position.
   
   Rava objects to his teacher Rav Nachman that this makes no sense, since the opposite positions in the Mishnah, that of Rabbi Yehuda / that of Rabbi Meir, has Rabbi Shimon endorsing the position. So again, we have a majority, or at least more than one. He doesn’t say it explicitly, but really any permutation, for instance entirely Rabbi Meir or entirely Rabbi Yehuda, would have another Tanna endorsing each of the positions. This doesn’t make sense as presented.
   
   So Rav Nachman (and thus Rabba bar Avuah) explain that it is a particular bias towards Rabbi Yossi, because nimuko imo, his reasoning is with him.
   

2. Is this a generally applied principle of pesak? How was it used before and after Rav Nachman?
   

3. Before, we have Issi ben Yehuda using it as a descriptor of Rabbi Yossi, alongside other positive descriptors of Tannaim (including Rabbi Shimon).
   
   Before, we have Rabbi Yehuda HaNasi using it (citing it?) to explain to his son why he rules like Rabbi Yossi despite two others arguing with Rabbi Yossi.
   

4. However, we don’t find named Amoraim using it ass a decisive principle. Rather, the Stamma employs it a few times, and attributes the belief to named Amoraim. We go through these cases.
   

5. One such case is Rabba and Rav Yosef traveling together, wanting to establish the eruv techumin at a particular tree known only to Rabba. He cites a brayta with Rabbi Yossi showing it is OK. The Stamma claims this is fabricated by Rabba, and Rav Yosef would have accepted it because Rabbi Yossi nimuko imo. I dislike this charge, and indeed, the Tosefta, unknown to the Stamma, actually has Rabbi Yossi saying that it is OK if only one party knows the location.
   
   (I also discuss another famous sugya in Pesachim, that if you are hanging, hang by a great tree. But I would explain this as that you should conduct the search to find a great earlier authority who says the same thing, not that you should fabricate such a quotation.)
   

6. If it isn’t in fact a widely accepted decisive principle by named Amoraim, I’d be hesitant to apply it to other gemaras where Rabbi Yossi argues. Especially as there are plenty of counterexamples where we rule against Rabbi Yossi. The Rishonim do invoke the principle, either explaining why we do rule like Rabbi Yossi or expressing wonder that we do not rule like Rabbi Yossi, but they are influenced by the repeated invocation by the Stamma.