Infallible?

Avodah
1

From https://vinnews.com/2026/05/05/five-ways-of-reading-a-gemara-that-no-longer-matches-the-world-and-how-the-baalei-hatosafos-read-theirs/ R Y Hoffman

The Rabbis were wrong. This is the most controversial of the five. Its earliest and most famous proponent is Rabbeinu Avraham ben HaRambam in his Maʼamar al Derashos Chazal, where he writes that Chazal were not infallible in matters of medicine and natural science and were entitled to rely on the best science of their own day. [As a parenthetic note, one of our recognized Gedolei Torah was behind the printing of this Rav Avrohom ben haRambam, and he received a phone call from Rav Aharon Kotler zatzal—about to castigate him for doing so. The Gadol instructed his talmid to tell Rav Aharon that he wasnʼt home. The Talmid did so, but Rav Aharon responded, “Put him on the phone right now!”] Regardless, Pachad Yitzchak (Rav Lampronti) cites this approach in connection with killing lice. Many later authorities reject it sharply—some calling it close to kefirah—while others, including significant Sephardic poskim, treat it as a legitimate, if narrow, option. As will be seen below, this is the one category about which one might reasonably hesitate.

Me-What would the reason be to “reasonably hesitate” if it seems the most cogent explanation?

KT
Joel Rich

2

We have discussed this in the past, with regard to killing fleas on Shabbos or eating maggots found within the meat. Where the reasoning given by Chazal doesn’t match the scientifically proven reality.

For example, in Apr 2019 I wrote:

The Gra and R Kook both hold that for every reason given for a halakhah there are usually many others not spelled out for us. So, if the reason for a heter is found to be scientifically wrong, we would need to be machmir (killing lice). But, if a reason for a chumerah were disproven, we have to assume there are other reasons still around sufficient to justify sticking with the chumera. So, they only change the halakhah to
add chumeros.

I heard RDLifshitz give shiur on maggots found in meat. Leshitaso, the maggots would be kosher. We have maggots in the meat because (1) there were microscopic maggot eggs laid in the meat, and (2) once the maggot hatched, it ate meat until it grew to visible size. But #1 doesn’t count, not being microscopic. It’s the meat that made the problem halachic – allowing the maggot to grow from micro- to visible size. And thus, it still is born from the meat" in a halachic sense.

And I would think parallel reason would permit killing lice on Shabbos. Assuming a bree[d] of lice with invisibly small eggs.

I got the impression that RDL would assume that this kind of reasoning could be found in every example.

I since had this theory:

Halakhah deals with reality as experienced first-hand. Not as it is. This is a topic in and of itself, but see my blog post in Aspaqlaria “Phenomenalism – Baruch sheKivanti!” and in particular the quote I copied from RYGB. (Just I gave a link to my copy because I added a translation.)

But even without that full side-topic, we see this is true of microscopic bugs and according to RDL, microscopic eggs of visible bugs.

But what this means is, halakhah OUGHT to follow Natural Philosophy rather than science. NP constructs theories given the world as we know it. The concept of testing theories with experiments didn’t happen yet. Science’s whole point is to get past the subjective experience to find what’s really out there.

So it’s not just that they tended to use the science of the day. They used a good description of how the world feels like it works.

As RGN writes, "כך הוא הדבר ככל האיסורים ובכל המצוות, שהגדרים . ההלכתיים נקבעים לפי ההתרשמות וההתייחסות של האדם -