[Avodah] changes in circumstances

[Micha Berger]

On Mon, Jul 05, 2021 at 09:01:30PM -0400, Akiva Miller via Avodah wrote:
> R' Joel Rich wrote about pig milk and asked:
>> so how can we ever take into account changes in
>> circumstances (e.g. Rabbeinu Tam on klei shir or how
>> we skirt medicine on shabbat rules)

> To me, this sounds very similar to "Why are we allowed to kill lice on
> Shabbos?", just applied to a different situation.

I don't see the parallel.

The question about lice on Shabbos is not that the circumstances changed.
Then we get into the question of the limits of precedent, and when do
you say the situation is new enough for precedent not to matter. Or,
as in RJR's examples, how broad was a gezeira and does the new situation
stand outside it? Did this gezeira get phrased in terms of its rationale,
so that by definition if the rationale doesn't fit the situation, the
gezeira doesn't.

Then there are cases of halachic engineering, where the situation changed
such that the old din is not only pointless, but a net minus. The poor
couldn't get loans, shemittah is derabbanan, so Hillel engineered
pruzbul (or maybe mass-implemented something until then only done
retail). Or selling chameitz. The old din applies, but we don't feel
moral problems with avoiding it because there is a worse outcome if
we obey.

Killing lice is different in that it's an issue where someone today would
be in the same situation, but having a different understanding of what is
happening in it. And the question becomes whether the precedent of a pesaq
or the coining of a taqanah are even valid if they are based on a mistaken
idea in Natural Philosophy. Was the explanation the cause, a post-facto
rationale by a later generation, the only stated reason coexisting among
many unstated ones...? Was the explanation even wrong, in the sense that
the world really does look that way, and how the situation is experienced
matters more than the science we cannot directly experience?

What I do see similar is the discusion on the thread about Tefillas
haDerekh from Lakewood to Monsey. Maybe today's urban sprawl means there
are far fewer opportunities to say tefillas haderekh.

In that thread, on Tue, Jul 27, 2021 at 10:53pm GMT, R Joseph Kaplan wrote:
> Or perhaps, when tefillat haderech was written, no one could contemplate
> or imagine a built up urban area like the one existing between Lakewood
> and Monsey.

Why would that be a problem? If the situation doesn't arise, then the
chiyuv is not chal.

I am reminded of the AhS saying that there were few reshuyos harabbim
deOraisa anymore since we don't build our cities around a central
market square that side on the main road. And by central he means
that streets converge on the square, lanes (mevo'os) on the street,
chateiros on the mevo'os.... He holds the lack of stratya upelatya in
modern city planning would allow community eiruvin even if there were
60 ribo. (Although I could picture a handful of counter-examples, like
Moscow with the Red Square.)

If the AhS could declare reshus harabbim deOraisa as not applying in
any of "our cities", what would be the difficulty with thinking it's
very hard to be chayav Tefillas haDerekh because of car travel?

So, whether or not the parsah needs to be empty, or maybe there is a
migrash beyond the last house (and I agree with Zev that "last house"
could well be the last one 70 amost and change from the previous),
maybe there is a ribu'a, maybe the ribu'a is aligned with the compass
points...

Truth is, if you look at hilkhos techum shabbos with all the clauses I
added in the previous paragraph, I may be living in a "city" that includes
the a rectangle that goes beyond Boston in the NE and Washington DC in
the SW! Techum under these changed circumstances...

:-)BBii!
-Micha

-- 
Micha Berger                 We are great, and our foibles are great,
http://www.aishdas.org/asp   and therefore our troubles are great --
Author: Widen Your Tent      but our consolations will also be great.
- https://amzn.to/2JRxnDF                      - Rabbi AY Kook