Saturday, December 12, 2015

Sources Indicating That Chazal Did Not Possess Perfect Scientific Knowledge:
Click Here

(a source list of rishonim, acharonim, and selected Talmudic-era passages, with quotations and translations)

Wednesday, July 24, 2013

Unpublished Comment on Cross-Currents: "Is Heresy Horrible?"

For the record, I submitted a comment to Cross-Currents regarding the following post:  Seems they're not going to publish the comment; can't figure out why not.  Here is the comment:

Excellent article. One critique:
“When faced with questions about Torah, our first response has to be loyalty to the Torah that we love.”
The problem with this statement is that on an individual level, if one’s loyalty to Torah is based on one’s belief in its veracity, then one’s first response to (substantive) questions regarding its veracity must logically be to confront the questions and determine the facts. For such a person, loyalty to Torah is a result of one’s search for truth, not a prerequisite for it.

Wednesday, November 18, 2009

Deceptive Memories and Yeridat Hadorot

A recent comment on R. Natan Slifkin's blog discusses an idea I've been thinking about a lot lately. See the third paragraph of the November 18, 2009 5:09 AM comment of G*3 to the post Quite well put. I don't necessarily agree with the rest of the comment.

Different Rabbis for Different Folks

Ponder the following:

Suppose the Skverer Rebbe (whom I know nothing about) rules that X is permitted. Suppose that R. Elyashiv and, for good measure, the entire Agudas Yisrael, believes that X is forbidden. Suppose Mr. A believes that R. Elyashiv is the greatest posek alive today, and that the Skverer Rebbe, though a talmid chacham, just doesn't measure up to him. Would Mr. A think it wrong of Skverer chasidim to engage in X, as per their rebbe's ruling? Generally speaking, I think not.

Now replace Skverer chasidim with disciples of R. Hershel Schachter (of YU), and replace X with the belief that Chazal made mistakes in science, or any number of other issues on which R. Schachter (among others) disagrees with R. Elyashiv. Shouldn't the attitude of Mr. A be the same? Shouldn't Mr. A consider it acceptable for R. Schachter's talmidim to follow his views? -- Unless Mr. A thinks that R. Schachter is not a talmid chacham.

Tuesday, July 07, 2009

Harry Potter and Divine Foreknowledge

The end of the chapter of Harry Potter and the Half-Blood Prince entitled "Horcruxes" is probably one of the most intellectually challenging passages in the entire Harry Potter series. It deals with the relationship between the prophecy regarding Harry and Lord Voldemort, and the fulfillment of that prophecy. I think it can be of use in explaining how free will and divine foreknowledge can coexist, though the discussion in Harry Potter is not entirely analogous.

Wednesday, May 20, 2009

On the Term "Torah Umadda"

I have written a letter to Rabbi Natan Slifkin suggesting that he not use the term "Torah umadda" in reference to his own position or "camp." The text (without salutations) can be found at

Sunday, May 04, 2008

Other Sources About Chazal's Science

My ambition is one day to compile a source list complementary to "Sources Indicating That Chazal Did Not Possess Perfect Scientific Knowledge," which will present rabbinic sources indicating that Chazal did in fact possess perfect scientific knowledge, or at least that scientific statements that go unchallenged in the Talmud are always correct. Unfortunately (or perhaps fortunately) I am much busier these days than I was back when I compiled the bulk of the original list, and I simply do not feel I have the time to produce any sort of decent work of the type I have just described. As an entirely inadequate and hopefully temporary substitute, I present below two small lists of sources (references only; no quotations) on the topic of Chazal's science which are not included in "Sources Indicating That Chazal Did Not Possess Perfect Scientific Knowledge." The first list consists of sources averring that Chazal's scientific statements - or at least those uncontested in the Talmud - were always correct. The second group of sources assert neither that Chazal were always right nor that they were sometimes wrong; these sources may nonetheless be of interest to those researching the topic of Chazal's science. Individuals marked with an asterisk (*) are also listed in "Sources Indicating That Chazal Did Not Possess Perfect Scientific Knowledge."

I apologize that these lists are currently extremely short. It goes without saying that there are far more sources of each type than appear here, many of which I am already aware of. I will try to add more sources to this post as my schedule permits. I am posting it now in this ridiculously abbreviated form so that I can solicit feedback and help in finding more sources. I request that anyone knowing of sources that ought to be cited in any of the three "science of Chazal" lists on this blog suggest them in the comments. Thank you in advance for your help.

Category 1: Chazal Did Not Err

Rema (R. Moshe Isserles; 1520-1572; Poland), Torat Ha’olah 1:2; 3:49.
R. Yehuda Briel (1643-1722; Italy), quoted in Pachad Yitzchak, by R. Yitzchak Lampronti, under the entry “Tzeidah.”
R. Yosef Shalom Elyashiv (1910- ; Israel), as quoted in "The Slifkin Affair – Issues and Perspectives," by R. Aharon Feldman, available at

Category 2: Neutral but Interesting

Rabbeinu Tam (R. Yaakov ben Meir Tam; c. 1100-1171; France), quoted in Tosafot, Shabbat 35a s.v. “Trei tiltei mil;” quoted in Shita Mekubetzet, Ketubot 13b.
Tosafot (12th-14th centuries, France-Germany), Pesachim 94a s.v. “Rabbi Yehuda omer mishekiat hachamah ad tzeit hakochavim arba milin.”
*Ramban (R. Moshe ben Nachman; 1194-1270; Spain-Israel), Bereishit 9:12; Bereishit 35:16; Devarim 18:9; “He’ara Nosefet” immediately following the end of Ramban’s commentary on Devarim (Mossad Harav Kook edition).
Maharal (R. Yehuda Loew; 1525-1609; Bohemia), Be’er Hagolah 6.
Vilna Gaon (Gra; R. Eliyahu of Vilna; 1720-1797; Lithuania), Hagahot Hagra 1 to Eruvin 76b.
R. Akiva Eger (1761-1837; Austria-Hungary), Gilyon Hashas, Pesachim 94b s.v. “Venir’in divreihem.”

Monday, April 07, 2008

Links to Audio and Video Shiurim by Rabbi Hershel Schachter

Rabbi Hershel Schachter is among the most masterful teachers of Torah I have had the privilege to see and hear in action. Below, I have assembled links to various recordings of his shiurim available online. These links are to web pages which themselves contain one or more links to recordings of Rabbi Schachter.

This list is undoubtedly incomplete. If you know of any shiurim available online in audio or video format that are not already linked to here, please let me know in a comment, and I will add the link.

If you possess a recording of a shiur (or many shiurim) by Rabbi Schachter or other YU-associated rabbis which you think is not currently available online, please inform me of that as well, and I will try to arrange to have it made available online.

Links to sites that link to shiurim:
Adath Israel Poale Zedek Anshei Ozeroff:
Kehillas Bais Yehudah Tzvi of Cedarhurst:
Kerem B'Yavneh:
OU: and search for "Schachter".
Torahspace (several pages of links):
YU Torah: