A Further Foie Gras Fabrication

Note: This post has been slightly edited shortly after initial publication.

From a Seforim blog post of six months ago by R. Dr. Ari Z. Zivotofsky:

Foie gras (pronounced “fwä-grä, meaning “fat liver” in French) is the fattened liver of a waterfowl that grew to 5-10 times its usual size due to gavage. Foie gras, a delicacy today rightly associated with the French who are indeed by far the largest producers and consumers of it, was for much of history an Ashkenazi Jewish expertise. This luxury item has been the subject of a great deal of controversy in recent years. …

The issue driving the current debate is animal welfare, or in the Jewish world, tza’ar ba’alei chaim. For hundreds of years, in traditional Jewish sources “stuffed goose” was indeed controversial, but not because of animal welfare. The debate revolved around potential treifot due to possible damage to the esophagus caused during the feeding process. it was a widespread debate involving the greatest of authorities. …

Despite the centuries long debate, force feeding geese was extremely common among Ashkenazic Jews. Many of the greatest poskim lived in regions where they would have been personally exposed to the process and yet none of them ever suggested that it was cruel and bordered on tza’ar baalei chaim. The issue was not even raised for discussion until the late 20th century.

I was quite struck by the claim that “none of [the greatest Ashkenazic poskim] ever suggested that [force feeding geese] was cruel and bordered on tza’ar baalei chaim”, and I was therefore very intrigued when I subsequently encountered what seemed to be a major counterexample:

בזמן כהונתו במונקאץ אסר על פיטום אווזים משום צער בעלי חיים, ולכן עורר עליו את חמתם של פרנסי העיר ונאלץ לעזוב את מונקאץ ולחזור לדינוב.

This account, of the stance of Rav Tzvi Elimelech Shapiro of Dinov (the Bnei Yissoscher), a major early nineteenth century Chassidic halachist, apparently directly refutes R. Dr. Zivotofsky’s claim – but the problem is that this account, while ubiquitous on the Internet (e.g., here, here, here, here, here, here, here, and in בית שלמה (פרפראות בדרך מוסר על פרשת השבוע) פרשת שמות התשע”ח), is apparently a fictionalized version of the Bnei Yissoscher’s position and what actually transpired in Munkács! None of the (identical) accounts are sourced, and while the Bnei Yissoscher’s staunch opposition to the consumption of force-fed geese is well known in the halachic literature, his own words on the subject are clear that while he did indeed advance a novel reason to prohibit them, that reason was not צער בעלי חיים (an issue that he does not raise), but rather a new type of טריפות: non-alcoholic fatty liver disease (NAFLD) / non-alcoholic steatohepatitis (NASH) culminating in liver failure:

ומזה הדבר היינו מהמדרש הנ”ל, נלמד גם כן תוכחת מוסר לאותן האנשים החטאים בנפשותם והקילו לעצמן לאכול אווזות הלעוטות, הנה חוץ לזה שכבר צווחו קמאי דקמאי להחרים על זה, אבל דבר חדש אני רואה טריפות דאורייתא דבר שלא שיערו כת הקודמים,

דהנה זה דבר ברור שאווזא הלעוטה אם לא ימהרו לשוחטה במשך ימי לעיטתה, דהיינו ג’ שבועות או יותר תמות כרגע, ומאין יהיה זה. אבל ראיתי כי האווזות האלו הכבד שלהם משונה ומתלבנת כולה, וגם היא ניתכת על ידי האור כשומן, וגם מתגדלת שלא כטבע הנהוג בכבד כאשר אתה רואה במדרש הנ”ל. וזה בא להאווזות הללו להיות הכבד תנור העוף, לבשל המאכל ולצמצם הדם הנשאר אחר שישלח אל איברי הגוף, וזה מלאכתו כל היום, והנה כל דבר שמעמיסים על איזה יצירה בעולם יותר מכוחו ומלאכתו, הנה יחלש ויתבטל כוחו לגמרי, כן הוא בענין הזה שמלעיטין האווזות והכבד המבשל מעמיסין עליו יתר על כוחו לבשל, הנה יחלש הכבד וימות כי יתבטל ממלאכתו לגמרי, ויתהווה נימוקות הכבד וישוב ללובן כמו המת, כי יתהפך הדם ללובן, על כרחך ימות הבעל חי כי נימוק הכבד והיא טריפה גמורה, על כן שומר נפשו ירחק מזה. ציינתי למשמרת לאות וכו’.1

[Incidentally, the Bnei Yissoscher’s language in the sentence beginning “אבל ראיתי” strongly suggests that he did not understand the changes to the liver as the goal of force-feeding, but rather as an incidental and problematic side effect.]

The Bnei Yissoscher’s vigorous and vehement opposition while in Munkács to the consumption of force-fed geese is indeed recorded by Rav Yekusiel Yehuda Teitelbaum (I – the Yetev Lev) and R. Shapiro’s great-grandson, Rav Tzvi Hirsch Shapiro – but they also make no mention of a concern for צער בעלי חיים (or of his being forced to abandon the city – they merely mention the success of his campaign of opposition, at least among his students and the G-d fearing):

והגאון הקדוש מהרצ”א ז”ל קורא תגר על המלעיטין בספר אגרא דכלה וכבר צווח ככרוכיא על זה בהיותו במונקאטש וביושב {יולניצא} (?) ותלמידיו קבלו עליהם דבריו2

וכן ידוע שבהיות אא”ז הנ”ל משכן כבודו אבדפ”ק מונקאטש שצווח ככרוכיא על אותן המקילין שבמדינה זו שאוכלין מאווזות הנלעטות ושפך חימה עליהם למאד והחמיר לאסור אותם וכל הירא את דבר ד’ בגלילותינו שמע לקולו וחדל מלאכול3

  1. אגרא דכלה סוף פרשת וארא, הובא בקיצור בדרכי תשובה סימן ל”ג סוף ס”ק קל”א []
  2. שו”ת אבני צדק יו”ד סוף סימן צ”ג []
  3. דרכי תשובה שם []

That’s What He Meant, More Or Less

Update: As ER explains in a comment, I made a grave cognitive error in formulating this post; the תפארת יעקב clearly meant exactly what the text says, although my point about the Tosafos in Eruvin stands. We shall reconsider this topic at greater length in a subsequent post, בג”ה.

In a recent comment on this blog, my friend ER makes the startling claim that the תפארת יעקב to חולין

resolves a difficulty by invoking the fact that pi is not precisely 3, rather a bit LESS!

I was flabbergasted to read this – after all, the work is a classic, and its author, Rav Ya’akov Gesundheit, was no קטלי קני באגמא, but a leading nineteenth century Polish Rav!

My perplexity deepened upon checking the citation; while the text does indeed read as ER reports, Rav Gesundheit attributes this idea to the Tosafos, and I was pretty sure that they at least knew perfectly well that Pi was greater, rather than less, than three!

ומשמע בהדיא בדברי התוספות בעירובין דכל שיש ברחבו טפח אין בהיקפו ג’ טפחים רק פחות מעט1

The resolution, of course, is that the text is corrupt, and should obviously read רק יותר מעט; this is evident both from the referenced Tosafos, as well as from the very context of his own remarks:


כל שיש בהיקיפו ג’ טפחים יש בו רחב טפח
מנא הני מילי א”ר יוחנן אמר קרא ויעש את הים מוצק עשר באמה משפתו עד שפתו עגול סביב וחמש באמה קומתו וקו שלשים באמה יסוב אותו סביב
והא איכא שפתו אמר רב פפא שפתו שפת פרח שושן כתיב ביה דכתיב ועביו טפח ושפתו כמעשה כוס פרח שושן אלפים בת יכיל
והאיכא משהו כי קא חשיב מגואי קא חשיב2

Whence are these calculations deduced?3 — R. Johanan replied: Scripture stated: And he made the ‘molten sea of ten cubits from brim to brim, round in compass, and the height thereof was five cubits; and a line of thirty cubits did compass it round about. [I Kings VII, 23. As the molten sea which had a diameter of ten cubits was approximately thirty cubits in circumference, the ratio of a diameter to a circumference must consequently be 10:30 = 1:3 approx.]
But surely there was [the thickness of] its brim? [Which increased the diameter to more than ten cubits: so that the ratio between diameter and circumference was greater than 1:3.] — R. Papa replied: Of its brim, it is written in Scripture [that it was as thin as] the flower of a lily; [Its thickness, therefore, amounted to very little and might be disregarded.] for it is written: And it was a handbreadth thick, and the brim thereof was wrought like the brim of a cup, like the flower of a lily; it held two thousand baths.
But there was [still] a fraction at least? — When [the measurement of the circumference] was computed it was that of the inner circumference.4


והאיכא משהו. משמע שהחשבון מצומצם וכן בפ”ק דב”ב (ד’ יד:) גבי שני טפחים שנשתיירו בארון ששם ספר תורה מונח שהיא בהיקפה ששה טפחים ופריך כיון דלאמצעיתו נגלל נפיש ליה משני טפחים וכן בתר הכי דמשני בספר דעזרה לתחלתו נגלל ופריך אכתי תרי בתרי היכי יתיב משמע דמצומצם לגמרי וקשיא דאין החשבון מדוקדק לפי חכמי המדות:5

So it is clear from both the Tosafos’s juxtaposition of the other passages, as well as their reference to the “scholars of measurements”, who certainly had a good idea of the true value of Pi, that they are debating whether its value is greater than, or exactly equal to, three, but certainly not less than that.

From the context of Rav Gesundheit’s own remarks it is ever more clear that he is suggesting that Pi is greater, not less, than three:


אמר גניבא אמר רבי אסי נקדרה כסלע [פירש”י: כמין ארובה עגולה ורוחב הקדירה כסלע מטבע רחב הוא] טרפה שאם תמתח תעמוד על הטפח [פירש”י: אי הוה מושכו לכאן ולכאן שיכנס העוגל לאורך או לרוחב תמצא בו טפח באותה קדירה]
אמר רבי חייא בר אבא לדידי מפרשא לי מיניה דגניבא אמברא דנהרדעא כסלע כשרה יתר מכסלע טרפה
וכמה יתר מכסלע אמר רב יוסף כגון דעיילן תלת קשייתא בציפא בדוחקא בלא ציפא ברווחא:6

Geniba said in the name of R. Assi: If a circular hole was cut out [in the rumen having a diameter] of a sela’, it is trefah, for then if you were to stretch out [the circumference thereof] it would amount to a handbreadth.
R. Hiyya b. Abba said: Geniba explained it to me on the bridge of Nehardea thus: A hole [having a diameter] of a sela’ is permitted; if it is more than a sela’ it is trefah.
What, for example, is a hole larger than a sela’? — Said R. Joseph. A hole through which three date stones with some of the fruit attached could pass with pressure, or easily without any fruit thereon.7

תפארת יעקב

שם כסלע כשרה כיתר מסלע טריפה. לכאורה משמע דהשתא לא חשבינן משום שאם תמתח תעמוד על טפח דהא בכסלע הוי טפח, אבל הרמב”ם פסק כיתר מסלע ונתן טעם שאם תמתח וכו’, ובאמת לא קשה מידי דעיקר הטעם לפי שאין החשבון מדוקדק לפי חכמי המידות ומשמע בהדיא בדברי התוספות בעירובין דכל שיש ברחבו טפח אין בהיקפו ג’ טפחים רק פחות מעט הילכך בעינן כיתר מכסלע דאז אם תמתח תעמוד על טפח:

Rav Gesundheit is resolving Rambam’s lenient ruling regarding a hole with the diameter of a סלע by proposing that since Pi is greater than three, a diameter of a סלע does not imply a circumference sufficiently large to render the animal טריפה.

  1. תפארת יעקב חולין נ: ד”ה שם כסלע כשרה כיתר מסלע טריפה – קשר []
  2. עירובין יד. – קשר []
  3. “This is the only instance where a doubt is raised in the Talmud in connection with a mathematical statement. This, as Zuckermann points out (Das Mathematische im Talmud, p. 23) proves that the Rabbis were well aware of the more exact ratio between the diameter and circumference and that the ratio of 1:3 was accepted by them simply as a workable number for religious purposes. Hence the question, ‘Whence are these calculations deduced?’ V. Feldman, Rabbinical Mathematics etc., p. 23.” []
  4. Ibid., translation and notes of the Soncino edition – PDF. []
  5. תוספות שם ד”ה והאיכא משהו []
  6. חולין נ: – קשר []
  7. Ibid., translation and notes of the Soncino edition – PDF. []

Terminally Ill Animals and Dead Horses

Rashba and Rivash

A celebrated assertion of a conclusive presumption in Halachah is the position of Rashba and Rivash that Hazal’s declaration that a טריפה cannot live more than twelve months is absolutely and indubitably true, and that if witnesses testify to a counterexample, we flatly deny their assertion, maintaining that Hazal are certainly correct and that the witnesses are perforce wrong. The practical import of this (possibly along with other arguments) is that we cannot invoke the purported fact of an animal classified as a definite טריפה having survived for twelve months as a basis to permit it:

שאלת בהמה שנמצאת יתרת אבר באותן אברים שהיא נטרפת בהן ובמקום שנטרפת בו ונתברר שעברו עליה שנים עשר חודש מי נימא כיון שעברו עליה י”ב חודש בודאי אינה נטרפת ונכשירנה דטרפה אינה חיה שנים עשר חודש. ואף על פי שראיתי ושמעתי מי שמכשיר ומיקל בדבר אני רוצה לעמוד על דעתך.

תשובה אם ראית ושמעת מי שמיקל ומכשיר ביתרת או בכל מה שמנו חכמים מכלל הטרפיות אל תשמע לו ולא תאבה אליו ולא תהיה כזאת בישראל וכל מי שמכשיר זה נראה בעיני כמוציא לעז על דברי חכמים …

[והאריך להוכיח שאי אפשר לטריפה לחיות י”ב חודש בשום אופן, ושוב כתב:] ומי שמעיד טעה בכך שלא היה מעולם … וכיון שכן אפילו יצאו כמה ואמרו כך ראינו אנו מכחישין אותן כדי שיהא דברי חכמים קיימים ולא נוציא לעז על דברי חכמים ונקיים דברים של אלו

וכיוצא בדברים אלו אמרו בההיא אתתא דאמרה ליה לרב אסי אני שהיתי לאחר בעלי עשר שנים וילדתי אמר לה בתי על תוציאי לעז על דברי חכמים וחזרה ואמרה היא רבי לגוי נבעלתי.

וכן בכרות שפכה שנקבו ביציו שאמרו שהוליד ואמר להם רב צא וחזר על בניו מאין הם ולומר שאי אפשר שיהיו דברי חכמים בטלים

וכיוצא באלו אני אומר כאן בבקשה מכם אל תוציאו לעז על דברי חכמים בכל מה שמנו חכמים בטרפיות הודאין ולא עשאום ספק טריפה. …

ואם תשוב ומה נעשה וכבר ראינו בעינינו יתרת ברגל ששהתה שנים עשר חודש זו היא שאמר רבי יהושע בן לוי לרבי יוסי בן נהוראי לא על דא את סמיך כלומר אי אפשר וכאילו אתה מעיד על שראית אותו בעיניך או סבה אחרת יש וכן בכאן אנו שואלין אותו שמעיד מאין אתה יודע ששהתה זו שמא שכחת או שמא טעית או שמא נתחלף לך בזמן או שמא נתחלפה לך בהמה זו באחרת שאי אפשר להעיד שתהא בהמה זו בין עיניו כל שנים עשר חודש.

ואם יתחזק בטעותו ויאמר לא כי אהבתי דברים זרים והם אשר ראו עיניהם ואחריהם אלך. נאמר אליו להוציא לעז על דברי חכמים אי אפשר ויבטל המעיד ואלף כיוצא בו ואל תבטל נקודה אחת ממה שהסמיכו בו חכמי ישראל הקדושים נביאים ובני נביאים ודברים שנאמרו למשה מסיני.1

ידעת האדון נ”ר שאין לנו לדון בדיני תורתנו ומצותיה על פי חכמי הטבע והרפואה, שאם נאמין לדבריהם אין תורה מן השמם חלילה, כי כן הניחו הם במופתיהם הכוזבים. ואם תדין בדיני הטריפות על פי חכמי הרפואה, שכר הרבה תטול מן הקצבים, כי באמת יהפכו רובם ממות לחיים ומחיים למות ויחליפו חי במת. כי אין ספק בנטלה הכבד ונשאר בה כזית שאנחנו מכשירים, הם יאמרו שימות לשעת. והן בחרותה בידי שמים ואחרים וכמה וכמה אחרים שאנחנו אוסרים כמו כל הסרכות וכל המראות הפוסלות בריאה. וכן בדיני הדריסה ואחרים שאין ספק, שהם מלעיגים בנו עליהם יוצק זהב רותח לתוך פיהם.

והרמב”ם ז”ל כששנה מעט ואמר שצומת הגידין הם בעצם התחתון בעופות, לא הודו לו, אחרי שלפי סוגית הגמרא נראה שהוא בעצם האמצעי, ולא נזכר בתלמוד חלוק בין בהמה לעופות. ואף על פי שהיה הרב ז”ל חכם בחכמת הרפואה והטבע ובקי בנתוח. כי לא מפי הטבע והרפואה אנו חיין. ואנחנו על חכמינו ז”ל נסמוך, אפילו יאמרו לנו על ימין שהוא שמאל, שהם קבלו האמת ופירושי המצוה איש מפי איש עד משה רבינו ע”ה, לא נאמין אל חכמי היונים והישמעאלים שלא דברו רק מסברתם, ועל פי אי זה נסיון, מבלי שישגיחו על כמה ספקות נפלו בנסיון ההוא, כמו שהיו עושין חכמינו ז”ל כמוזכר בפרק המפלת אני מביא ראיה מן התורה ואתם מביאים ראיה מן השוטים. ובכמה ענינים בסוד היצירה הם חולקים על דברי רז”ל, כמו צורת יצירת הולד לארבעים יום וקודם לכם מיא בעלמא הוא וכגון אביו מזריע לובן שממנו עצמת וגידין וכו’ והם סוברים שהכל מן האם וזרע האב פעולתו להקפיא ולהעמיד זרע האשה כפעל הקיבה להעמיד החלב. וכגון אשה מזרעת תחלה יולדת זכר וכו’ והם דעתם בהפך. וכן במה שאמרו ז”ל שלשה חדשים האחרונים תשמיש יפה לה ויפה לולד. והם סוברים בחדש השמיני קשה לה מאד. גם בזה אפשר שיהיה דעתם כנגד דברי רז”ל כי [ב]אולי נסו באחת או בשתים וראו שנגמר בתחלת תשיעי. ואולי היה בר ז’ ואשתהי או שהיו מבעילות קדומות. ואף אם מסרום לשומר, אין אפוטרופוס לעריות ואימר שומר בא עליהן. ויותר יש לנו להאמין בשמואל או לחוש לדבריו דנהירן ליה שבילי רקיעא. ובחכמת הרפואה העיד על עצמו ואמר לכל מילי ידענא אסותיהו. וגם חכמי הרפואה לא ראית בדבריהם שיאמרו שיצא מכלל נפל אף כשמת בן יומו, אבל אולי אמרו שאפשר שתגמר יצירתו לתחלת תשעה חדשים. ועוד שאין להפליא על הרופאים שהרי גם דעת רבי יהודה היה כן. אלא שהרמב”ם ז”ל וחבריו חשו לדשמואל. וגם שנראה להם פירוש כלו חדשיו שיהיו כל תשעה שלמים.2

This uncompromising stance of Rashba and Rivash is not, of course, the only perspective on the topic – this question lay at the heart of the great Slifkin Controversy; as Rav Aharon Feldman put it:


There are many places in the Talmud where statements made by the Sages seem to contradict modern science. The most common are the cures and potions which the Talmud gives for various diseases. Our great halachic authorities have noted the phenomenon that these cures, in the vast majority of cases, do not seem to cure illnesses in our times.

The most widespread explanation offered for this is nishtanu hatevaim, “nature has changed” – cures that worked in the times of the Talmud are no longer effective. There are many examples of illnesses and cures, which because of environmental and nutritional differences and physical changes to the body over the years are no longer effective. Another explanation is that we cannot reproduce these cures, either because the definitions or the amounts of the ingredient of these cures are unspecified in the Talmud. It has also been suggested that the cures had their effect on the inner, spiritual level of the affected person, and therefore were effective only for the people of the era of the Sages who were on a higher spiritual level than nowadays but not for later generations when increased physicality did not permit the cures to take effect.

Against these explanations, there is another opinion which Slifkin uses explicitly and implicitly in his books. This theory goes as follows. The Sages based their wisdom on the medical knowledge of their times. This would seem perfectly legitimate, for why should they not rely on the experts of their time on issues not directly addressed by the Written or the Oral Law? Therefore, when subsequently medicine indicates that these cures are ineffectual, there would be nothing disrespectful in asserting that the scientific knowledge of antiquity available to the Sages was flawed.

This approach is mentioned by many eminent authorities in Jewish history. Rav Sherira Gaon mentions it with respect to cures. R. Avraham, son of the Rambam, mentions it with respect to all science and the Rambam with respect to astronomy. Pachad Yizchok says that statements in the Talmud which seem to uphold spontaneous generation are incorrect, even though we do not change any laws based on their words. Rav Shamshon Refael Hirsch applies this argument to animals mentioned in the Talmud which do not seem to exist nowadays. Finally, a conversation with R. Eliyahu Eliezer Dessler recorded by Rabbi Aryeh Carmel indicates a somewhat similar approach.

This approach (henceforth, that of R. Avraham) is used often by Slifkin to explain many difficulties he has with the Sages’ statements. With it he explains why we have no record of certain animals mentioned in the Talmud, and why certain rules of the Sages regarding animals seem to have exceptions. Because they based themselves on the information available at their time, they simply made a mistake.

This theory, more than the first, has caused the most misunderstanding. How could Slifkin be faulted for espousing a view stated by giants of previous generations?

The answer to this question is that although these giants did indeed espouse this view, it is a minority opinion which has been rejected by most authorities since then.

In Lev Avraham Dr. Abraham Abraham-Sofer, discusses why the cures mentioned in the Talmud should not be relied upon in actual practice. As above, he explains that either a) the cures worked for the Sages but not for us; or b) following R. Avraham, that the Sages erred when they thought that these cures work. In a note to a later edition of this work, the world famous authority R. Shlomo Zalman Auerbach asked to add the following comment: “The principal explanation is the other views; that which is written “when the Sages spoke etc.” [R.. Avraham’s view], should be mentioned in the name of yesh omrim.” This means that the view of R. Avraham is a minority opinion which only “some say.”

Ten years later, a scholar, about to publish a book on the topic of Torah and health, asked R. Shlomo Zalman how an opinion held by such giants of Jewish history be relegated to the position of yesh omrim? Rav Auerbach responded in a letter stating that he did not remember his sources (it was ten years later), but he believes one source to be that it is the accepted opinion of poskim that we rely on the medical opinion of the Sages to violate Shabbos even though according to modern medical opinion the cures are ineffectual and we are violating Shabbos unnecessarily. Thus, for practical purposes we reject the view of R. Avraham.

There are other sources that this opinion is only one which “some say.” In countless places where the commentaries, whether Rishonim or Acharonim (Early or Later Authorties), are faced with a contradiction between the science of their times and a statement of the Sages, they commonly apply the principle, nishtanu hateva’im (“nature has changed”). Had they held R. Avraham’s view, they would have simply explained that the Sages erred in following whatever was the medical or scientific opinion of their times.

The Rivash, the Rashba and the Maharal write, as well, that it is forbidden to say that the Sages erred in matters of science.

Leshem Shevo Ve-achlama writes:

The main thing is: everyone who is called a Jew is obligated to believe with complete faith that everything found in the words of the Sages whether in halachos or agados of the Talmud or in the Midrashim, are all the words of the Living God, for everything which they said is with the spirit of God which spoke within them, and “thesecret of God is given to those who fear Him (סוד ה’ ליראיו).” This is just as we find in Sanhedrin 48b that even regarding something which has no application to Halacha and practical behavior, the Talmud asks regarding [the Sage] Rav Nachman, “How did he know this?” and the reply given is [that he knew this because] “The secret from God is given to those who fear him….”

The Chazon Ish, considered by many to be the posek acharon (final Torah authority) for our times, writes in his “Letters” that “our tradition” is that the shechita of someone who denies the truth of the Sages whether in the Halacha or Aggada (the non-halachic parts) of the Talmud is disqualified just as is someone who is a heretic. He adds that experience has shown that those who begin questioning the truth of the Sages will ultimately lose their future generations to Torah.

Why does mainstream opinion reject R.Avraham’s opinion? This is not because they considered the Sages greater scientists than their modern counterparts. Rather, they believed that, unlike R. Avraham’s view, the source of all the knowledge of the Sages is either from Sinaitic tradition (received at the Giving of the Torah) or from Divine inspiration. That they were in contact with such sources in undeniable. How else could we explain numerous examples where the Sages had scientific information which no scientist of their time had? How were they so precise in their calculations of the New Moon? How did they know that hemophilia is transmitted by the mother’s DNA, a fact discovered relatively recently? How did they know that “a drop exudes from the brain and develops into semen” without having known that the pituitary gland, located at the base of the brain, emits a hormone which controls the production of semen. None of this could have been discovered by experimentation Either they had a tradition directly teaching them these facts, or they knew them by applying principles which were part of the Oral Torah regarding the inner workings of the world. Thus they knew the precise cycle of the moon; they knew that there was a relationship between the coagulation of blood and motherhood; and they knew that there was a relationship between the brain and male reproduction.

Furthermore, the Talmud is not a mere compilation of the sayings of wise men; it is the sum total of Torah- she-be-al-peh, the Oral Torah which is the interpretation of the Written Torah. It is, then, the word of G-d, for which reason we are required to make a birchas hatorah (a blessing) before we study it, which we do not make before studying other wisdoms. As the Leshem cited above says, if even regarding matters which are not related to halacha, the Sages say, sod Hashem liyerav, “G-d reveals the secrets of nature to those who fear him,” then certainly there must have been siyata dishmaya (Divine assistance) and even ruach hakodesh (a Divine spirit) assisting the Sages in their redaction of the Oral Law. It is therefore inconceivable, to these opinions, that G-d would have permitted falsities to have been transmitted as Torah She-be-al-peh and not have revealed His secrets to those who fear Him.

One of the most powerful reasons why R. Avraham’s opinion was rejected by most opinions, is the introduction of the wisdom of Kabbalah of the Ari Zal in the sixteenth century. This cast the Sages in another dimension. Before then, many authorities had held that the esoteric wisdom described in the Talmud as Ma’aseh Breyshis and Ma’aseh Hamerkava was science and philosophy. After the introduction of Kabbalah it became clear that these were the Sefer HaYetzira, the Zohar and the Tikkunim. This was accepted by the overwhelming majority of Torah scholars since then. Kabbala made it clear that when the Sages spoke, they based themselves on their knowledge of the mysteries of creation. This would give them an accurate knowledge of matters of natural science as well.

In any event, R. Avraham’s opinion is a minority opinion, one of many which have fallen by the wayside in the course of the centuries and which we do no longer follow. Thus, on the issue of the credibility of the Sages as well, the signatories to the ban were correct in terming Slifkin’s books as perversions of the correct approach to the Sages’ words.3

My friend Rabbi Asher Benzion Buchman notes Rav Moshe Feinstein’s view that Rashba’s position was only tenable in his era of dreadfully primitive science and poor communication, but that contemporary scientific conclusions are so well established that they simply must be accepted as correct, and that a different approach must be found to reconcile them with the Talmud:

Rashba’s and Rivash’s Rejection of Science

Rivash justifies his assault on the evidence presented by doctors and scientists of his day by noting that they did not use repeated controlled experiments to come to their conclusions but merely made claims based on superficial examination. Rashba also speaks of their unreliability in testing animals for treifos, saying that they cannot be trusted to have observed the same animal for the entire 12-month period needed to establish non-treifus and are likely to have miscounted or switched animals. In his own day, Ramban maintained that “we must not deny the evidence of our own eyes,” but a generation later the greatest students of his school were doing just that. Nevertheless, we can understand why they did so. Science was so primitive, medicine so ineffective, and so little was understood—that even the most brilliant and educated of men could believe that science had absolutely no reliability. Indeed, “scientific” claims were not the result of rigorous scientific examination and one could be justified in discounting them if they ran against what seems to be Chazal’s intent. However, seven hundred years later it would be incorrect to make these same claims, and thus it is inappropriate for Rav Feldman to look to these Rishonim to validate his anti-science arguments.

Hilchos Treifos and Rav Moshe Feinstein’s Acceptance of Scientific Fact

Seven hundred years later, the poskim of the previous generation had no intention of accepting this attitude of Rashba and Rivash. When confronted with a contradiction between what medicine tells us about wounded and sick animals and the treifos that Chazal have handed down to us, the Chazon Ish and Rav Moshe Feinstein zt”l never considered the possibility that the doctors were wrong. Rav Moshe notes the position of Rashba and explicitly explains that his attitude is incorrect. He tells us that in the days of Rashba, long-distance communication between areas was so limited that Rashba was unaware of what had been proven elsewhere and thus was skeptical when told that certain wounds could be cured. According to Rav Moshe, Rashba is just wrong and today in gan eden he admits it. Although the present-day Talmudic student is trained to believe that a Rishon can never be considered wrong and our task is merely to explain the differing opinions, this is not Rav Moshe’s opinion. In this area, where a Rishon has predicated his position upon the stance that observable fact must be denied, the position of that Rishon must be rejected. [See the rest of the article for R. Buchman’s discussion of the views of Rav Moshe and Hazon Ish.]


In the laws of treifos and elsewhere, indeed Rashba and Rivash rejected the apparent reality that they were faced with, assuming that Chazal were more reliable than facts established by science. But this attitude was only viable in a time when science was unreliable and rightly viewed with skepticism. The leading poskim of the last generation, Rav Moshe Feinstein and Chazon Ish, living in an era where no rational person would deny the truths of science, followed the lead of Ramban. They demanded that we accept the evidence of our own eyes and proceeded to reconcile the difficulties presented by modern observation by explaining that halacha was not meant to reflect scientific reality—and resolved apparent contradictions with arguments base on lomdus. Rav Moshe tells us explicitly that Rashba himself, living today, would no longer maintain his position. Still, both Ramban and Rashba shared a common belief that the knowledge of the physical world that Chazal had was superior to that of modern scientists. Ramban believed that Chazal’s understanding in this area was profound, for they were the masters of the superior “spiritual” sciences. Those following this school of thought believed that the original halacha l’Moshe misinai included the medical details of what constitutes a fatal wound that makes an animal a treifa. Both Rashba in his day and Rav Moshe Feinstein in our day worked with this idea. Nevertheless, Ramban himself did not consider Chazal infallible in these matters and was open to the possibility that they had erred in matters of science. He insisted that that we never deny the evidence of our own eyes.

Rambam’s approach was different from those that came after him, believing that: 1) halacha works in harmony with the rules of nature; 2) there is no such thing as superior “spiritual” sciences and the mesora from Sinai did not include any advanced knowledge of the natural sciences—the halacha l’Moshe misinai of treifa only gave basic medical guidelines; and 3) the process of Talmud Torah that Chazal were entrusted with,was the pursuit of truth. This quest is ongoing and in hilchos treifos the advances of science would enhance their understanding of Torah. In his attempt to discredit Rabbi Slifkin, Rabbi Feldman turns to the words of Rashba and Rivash– and maintains that “it is forbidden to say that the Sages erred in matters of science.” How unfortunate it is that many of the rabbinic authorities of our day have rejected the rationalism of Ramban. How sad it is that they have not embraced the principles of Rambam who viewed Talmud Torah as an ongoing pursuit of truth.4

Although it is true that Rav Moshe insists that the conclusions of contemporary science are so compelling that Rashba himself would certainly concede their correctness, it nevertheless does not really follow that:

it is [therefore] inappropriate for Rav Feldman to look to these Rishonim to validate his anti-science arguments.

Rav Moshe’s point is merely that as the reliability of the relevant science is also indubitable, we must therefore find some way to reconcile the science with the Talmud, such as via a reinterpretation of the latter, and not simply dismiss the former as unreliable and wrong, but nowhere does he reject Rashba’s basic premise of the authoritativeness of Hazal’s science, correctly understood.

Rav Shlomo Zalman Auerbach

We have seen Rav Feldman’s mention of Rav Shlomo Zalman’s attitude toward the position of Rav Sherira Gaon and Rav Avraham ben Ha’Rambam; here’s the full story, shown to me years ago by my father.

Rabbi Dr. Avraham Sofer Abraham, in his work on medical Halachah Lev Avraham, brings a consensus view that we do not attempt to utilize the Talmudic remedies for illness. He cites several justifications for this, one of them being the simple argument that Hazal’s medical knowledge was merely drawn from contemporary ‘science’, and not from their religious wisdom, and as such, it has no special authoritative value, and we therefore ought to follow the more advanced and accurate prescriptions of later science:

אסור – מכמה סיבות – לנסות הרפואות המובאות בתלמוד: … חז”ל כשדברו על עניני רפואה וטבע, דברו לפי הידוע שבזמנם, ולא על פי ידיעתם בתורה הקדושה ופירושיה, ולכן אנו צריכים לקבל דעתם בדברים כאלה רק אם הדבר גם מקובל על פי ידיעתנו ברפואה היום [ר’ שרירא גאון (אוצר הגאונים, חלק התשובות, גיטין ס”ח ע”ב סימן שע”ו): ר’ אברהם בן הרמב”ם (מאמר על אודות דרשות חז”ל, ריש עיון יעקב) – המקורות האלה הראה לי ידידי הרב פרופ’ יהודה הלוי שליט”א: וראה שם בר’ אברהם בן הרמב”ם שמביא כדוגמה הדין של אבן תקומה (גמרא שבת ס”ו ע”ב) “שאמרו שמונע להפיל הנפלים שלא נתאמת” – אולם הרמב”ם (הלכות שבת (פרק י”ט הלכה י”ד) והשו”ע (סימן ש”ג סעיף כ”ד) מביאים את דינא דגמרא להתיר חילול שבת דאורייתא וצ”ע: וראה גם במאירי על נדה י”ז ע”ב ד”ה זהו. וראה בחזו”א יו”ד סימן ה’ ס”ק ג’. וראה הערתו של הגרש”ז אויערבאך שליט”א עמוד י”ט.]5

The last line refers to a comment of Rav Shlomo Zalman Auerbach which tersely declares this perspective non-normative:

העיקר הוא כשאר הטעמים, ומה שכתב “חז”ל כשדברו” וכו’ נכון לכותבו רק בשם י”א6

Rabbi Yosef Yitzhak Lerner, in the introduction to his classic Shemiras Ha’Guf Ve’Ha’Nefesh, relates an interchange that he had with Rav Shlomo Zalman about this remark:

ושאלתי להגרש”ז שליט”א מי הוא זה שחולק על דברי רב שרירא גאון ור’ אברהם בן הרמב”ם. וכתב לי וז”ל: כעת אינני זוכר אם יש מישהו שממש חולק או אפילו אם יש מישהו שיכול לחלוק עליהם, אך יתכן שכוונתי דהואיל ורבים כתבו הטעם של שינוי הטבע ולא הזכירו כלל מפני שיפור וידע בדרכי הרפואה בזמנינו, לכן העירותי שראוי לכתוב בשם “יש אומרים”, ובפרט שבעניני שבת יש שמתירים מלאכת שבת אף שלדעת הרופאים אין שום סכנה, עכ”ל.7

The continuation of this discussion appears in Rabbi Yehiel Michel Stern’s biography Reb Shlomo Zalman:

Rabbi Lerner explained that this source [of a dissenting view to that of Rav Sherira Gaon and Rav Avraham ben Ha’Rambam] was very important to him, since many people who are interested in returning to Torah Judaism were asking questions about statements made by the Sages of the Talmud that conflict with modern medical science.

A while later he received a letter from the Rosh Yeshivah, stating, “I cannot recall who it is that differs with Rabbi Sherira Gaon and Rabbi Avraham ben haRambam. But since the Shulchan Aruch states that one is allowed to desecrate the Shabbos for various kinds of diseases which contemporary doctors do not consider life threatening, it follows that the halachah is that we should ignore medical science if it disagrees with Talmudic medicine.”

Rabbi Lerner wanted to publish this letter in his forthcoming book. However, someone advised him against it, stating that “it would be disrespectful to publicize a letter in which the Rosh Yeshivah admits that he does not recall something.”

Faced with this dilemma, Rabbi Lerner talked it over with Reb Shlomo Zalman.

“I can’t understand the person who gave you that advice,” the Rosh Yeshivah said. “Look, you did not know who held the opposing view. So you asked me, because you thought that I am a great talmid chacham who no doubt knows the answer. But you found out that I do not know it either.

Now, if you print my letter, and your book is published, it is quite likely that some scholar will read the letter and will be able to tell you which Rishon (early authority) holds the opinion that one should disregard a doctor’s advice if it runs counter to the opinion of the Sages. In that case, you will have the answer you were looking for. If and when this happens, please let me know. In the next edition of your book you can publish the information, so everyone will know it.

“On the other hand, if you don’t publish my letter, not only will you and I not know the answer, no one will know it. So what do you gain by not publishing the letter?

“I am not only giving you permission to publish my letter,” Reb Shlomo Zalman summarized, “I definitely want you to publish it. And remember, if you find out the answer, don’t forget to let me know right away.”

At the Rosh Yeshivah’s behest, Rabbi Lerner published the letter …

As it turned out, within only a few months, Rabbi Lerner received a letter from a Talmudic scholar indicating that the Rivash (simon 447) explicitly disagrees with Rav Sherira Gaon and Rabbi Avraham ben haRambam. A short time later, another scholar remarked that the Rashba (in Mishmeres Habayis 4:1) also differs with the two Rishonim.

Rabbi Lerner rushed to bring the news to Reb Shlomo Zalman, who was delighted. “We have learned something we did not know before,” he exulted. “Now you see that I was right to tell you to publish my letter. Now you know it, I know it, and when you report it publicly, everyone will know it.”8

Revisionist Readings Of Rav Shlomo Zalman

Prof. Yehuda Gellman and Meir Ben-Tzvi, in lengthy rebuttals to the aforementioned letter of Rav Feldman, argue that he has misunderstood Rav Shlomo Zalman. Prof. Gellman:

When I read [Rav Feldman’s] reference to R. Shlomo Zalman I was perplexed. The passage claims that Rav Shlomo Zalman rejected the view that our Sages were fallible on matters of science. Yet, once I spoke to a person who is one of the most prominent Roshei Yeshivah in Eretz Yisrael about this issue of our Sages and science. This Rosh Yeshivah, whose name I will not divulge here, answered me in these words, which have stuck in my memory: “I [the Rosh Yeshivah] asked R. Shlomo Zalman this very question. And R. Shlomo Zalman’s answer was: ‘When Mashiach comes several halachot will have to be changed.’” From this we can clearly conclude that R. Shlomo Zalman held that our Sages had erred in some matters of scientific fact, and therefore in the new order of Messianic times certain laws would have to be changed, but until then the integrity of halachah demanded that we be absolutely subjected to the decisions of our Sages, and indeed this was the will of Hashem. Thus, rejecting R. Avraham ben Harambam in practical terms would be consistent with accepting his position regarding the truth of the matter, that our Sages were fallible on scientific matters.

My perplexity concerning the testimony of this Rosh Yeshivah was diminished when I saw the quotation to which Rabbi Feldman refers. …

On my understanding, here R. Shlomo Zalman does not denigrate the view of Sherira Gaon and R. Avraham ben HaRambam. On the contrary, he says he does not know if there is someone who is able to argue with that view. Specifically, he does not invoke the fact that we do not rely on that view in practice as a reason for thinking it false. The reason he gives for calling this view a secondary one (yesh omrim) is that many others have explained the disparity between Torah and science by saying nature has changed. I see here no rejection of the view that our Sages were scientifically fallible, and so my original understanding of Rav Shlomo Zalman’s personal view stands: He held that our sages were wrong in their factual rationale for various laws, and that this would be amended when the Messiah comes. In the meantime we are obligated to follow the existing laws.9

This rereading of Rav Shlomo Zalman to reconcile him with the view that “our sages were wrong in their factual rationale for various laws”, based on a conversation with an anonymous Rosh Yeshiva “whose name [Prof. Gellman] will not divulge here”, does not seem entirely plausible. Prof. Gellman proposes that Rav Shlomo Zalman “[accepts Rav Rav Avraham ben Ha’Rambam’s] position regarding the truth of the matter, that our Sages were fallible on scientific matters”, and merely “[rejects it] in practical terms” – but the initial comment of Rav Shlomo Zalman was in response to the mere citation of Rav Avraham’s rationale, along with several others, in justification of the more or less universally accepted principle that we do not generally utilize the medical remedies of the Talmud. Rav Shlomo Zalman certainly accepted this practical ruling, and if he also wholeheartedly endorsed, at least theoretically, the position of Rav Avraham, what, exactly, required emendation? Prof. Gellman’s understanding is particularly difficult in light of the conclusion of the story cited by R. Stern, that Rav Shlomo Zalman was “delighted” to learn of the position of Rivash, who unequivocally and uncompromisingly rejects the very idea of the fallibility of Hazal’s scientific understanding, and the implication is that this was the perspective alluded to in his original comment.


This is not an accurate presentation of R. Shlomo Zalman’s letter. The citation is actually as follows: …

It was not merely that R. Shlomo Zalman “did not remember his sources” – it was that he did not remember if there is anyone who argues with this approach or even if there is anyone who is able to argue with it.

Yes, but he nevertheless flatly declared, in his initial comment, that the stance of Rav Sherira Gaon and Rav Avraham ben Ha’Rambam is non-normative.

What is undeniably clear is that Rav Shlomo Zalman Auerbach (unsurprisingly) endorsed the approach of Rav Sherira Gaon and Rabbeinu Avraham ben HaRambam as a legitimate alternative approach. He did not say that it should be rejected as unacceptable, and certainly not as heretical.

Thus, for practical purposes we reject the view of R. Avraham.

Which “practical purposes”? True, for actually ruling in halachic purposes, as Rabbi Slifkin himself writes that according to most opinions the halacha holds true regardless of the perceived consistency of the explanation that accompanies it. But this is certainly not true for our way of understanding strange (and non-halachic) statements in the Gemara!10

Ultimately, of course, our own comments notwithstanding, trying to posthumously ascertain Rav Shlomo Zalman’s true attitude from a few relatively brief, informal and semi-formal comments is really an utterly quixotic task …

On the general topic of conflicts between (the apparent meaning of) Torah and science, see also our “A Woman Is Not an Elephant” – Some Jewish, Islamic and Classical Perspectives On the Conflict Between Authority and Truth.

  1. שו”ת הרשב”א חלק א’ סימן צ”ח, הובא ברמ”א יו”ד סימן נ”ז סעיף י”ח, ועיין ש”ך שם ס”ק מ”ח []
  2. שו”ת הריב”ש סימן תמ”ז []
  3. R. Aharon Feldman, THE SLIFKIN AFFAIR – ISSUES AND PERSPECTIVES, pp. 5-8, available here: DOC. []
  4. Rabbi Asher Benzion Buchman, Rationality and Halacha: The Halacha L’Moshe MiSinai of Treifos, in Hakirah Volume 4 (Winter 2007) pp. 121-135, available here: PDF. []
  5. לב אברהם חלק ב’ פרק י”ד אות ד []
  6. שם בהסכמתו לספר עמוד י”ט []
  7. ספר שמירת הגוף והנפש, מבוא סוף פרק ו []
  8. pp. 95 – 97 []
  9. Prof. Yehuda Gellman (link?), A RESPONSE TO RABBI AHARON FELDMAN’S “THE SLIFKIN AFFAIR –ISSUES AND PERSPECTIVES”, pp. 6-8, available here: DOC. []
  10. Meir Ben-Tzvi, A Response to Rabbi Aharon Feldman’s Article THE SLIFKIN AFFAIR – ISSUES AND PERSPECTIVES [Second Version (Greatly Expanded Throughout)], pp. 18-19, available here: RTF. []