[Avodah] Mumcheh Kemeia

Micha Berger micha at aishdas.org
Thu May 21 14:48:55 PDT 2020

On Mon, May 18, 2020 at 01:45:49PM +0300, Moshe Koppel via Avodah wrote:
> On Thu, May 7, 2020 at 2:31 PM Micha Berger <micha at aishdas.org> wrote:
> > ...Shabbos 61a yesterday, and what defines a kemeia mumcheh.
> > Chazal appear to define expertise in the same terms as chazaqah
> > -- it it works three times.
> >
> > Double blind studies weren't invented yet. So, if the kemeia works
> > 3 times out of 40, it's a kemeia mumcheh? ...

> Apologies for not getting to this sooner. See what RNER z"l wrote in Yad
> Peshutah on Hil. Shabbos 19:13-14, where Rambam discusses the issue. He
> doesn't get into your statistical question there at all, but says what
> you'd expect him to say about quackery. (You can navigate there in Otzar
> Hachochma, but I can't get a direct link to work.)

RNER doesn't really touch my question that chazaqah doesn't prove much if
it works 3 times out of dozens. With no comparison to doing nothing.

On 13 the focus is on medicines the doctors think work. The
non-professional can't do anything but go by expert opinion. So, Chazal
permitted he rely on them -- even for hotza'ah. RNER also brings the
Me'iri, who splits the reasoning into two: 1- The doctors may have been
wrong, but no one could have known. 2- Placebo effect.

0n 14, he discusses Rabbeinu Chananel's girsa, in which either the
kemei'ah itself or the author could be tested and proven. As well as
the question of whether mumcheh means worked three times or on three
different people.

But still, the absolute number 3 isn't discussed in comparison to a
statistical approach.

Tir'u baTov!

Micha Berger                 Today is the 42nd day, which is
http://www.aishdas.org/asp   6 weeks in/toward the omer.
Author: Widen Your Tent      Malchus sheb'Yesod: Why is self-control and
- https://amzn.to/2JRxnDF     reliability crucial for universal brotherhood?

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