As we discussed, when two pairs of eidim offer contradictory testimony, Tosfos holds that migu cannot bolster the credibility of one pair over the other. Because trei k’meh, i.e. the credibility of 100 witnesses is no better than 2, it stands to reason that the credibility of 2 witnesses who have a migu is also no better than the credibility of 2 witnesses without -- there is simply nothing, no other proof or combination of proofs, which trumps two witnesses. Yet, after citing this explanation of Tosfos, the Sha’ar haMisphat holds that if one of the litigants, a ba’al din, has a migu in a case where witnesses contradict each other, his claim wins. Why should this be so? If there are two witnesses that back up the plaintiff’s story and two witnesses that back up the defendant’s story, and no evidence in the world that trumps witnesses, why does throwing the litigant's migu into the mix tilt the scales?
R’ Elchanan’s answer to this question (Koveitz Shiurim #4) is one of the classics. The simple way to understand migu is that it is a siman, an indication that your claim is truthful. Since if you wanted to lie you could tell a better lie, the weakness of your claim is a mark in its favor. But this, says R’ Elchanan, is only half the story. It’s not just the possibility of a better story that bolsters your claim, but rather we view your defense as if you had actually told the better story – you get the benefit of a better claim without actually having to articulate it. This is known in yeshvish-ese as having a “zechus hata’anah”.
Coming back to our question, where two litigants and witnesses are at a standoff about fact X, migu does not help either pair of witnesses because it adds no more credibility to testimony about X than the witnesses already have. But where the litigant has a migu, that’s another story. A migu in the hands of the plaintiff or defendant says that in addition to claim X which is under dispute, their zechus hata’anah means claim Y is also implicitly on the table to their benefit. Since the standoff between the witnesses is only with respect to the facts about X, the addition of claim of Y can tip the scales in one party’s favor.
I am posting this because it tangentially came up in the comments to the post about migu and eidim, but it is a piece that sticks in my mind for another reason. Last year my son was in 9th grade and learning Baba Basra and I remember early in the year talking to him about a migu sugya and discovering that he had never heard of this idea of “zechus hata’anah”, so we learned it together. This year (bli ayin hara) I don’t think I can come up with a single R’ Elchanan on the masechta he is learning (and I would not want to go head to head with him on other masechtos either) that he does not know already. As I’ve written before, if you want to take see the type growth in learning you should aspire for, just look at your kids. Every year is an exponential leap beyond the level of the previous year, whether it be knowing R' Elchanan or simply moving from Reishis Keri'ah to knowing how to read a pasuk.