Monday, January 14, 2013

Rivers And Other Rationalist Miscellenia

1. In the comments to the post "Sugar For Elephants," a reader drew my attention to another example of an early Acharon pointing to an inaccurate statement made by a Rishon due to his geographical location. Radvaz negates the view of R. Eliyahu Mizrahi (and effectively many others) who identified the "River of Egypt," stated to be the border of Eretz Yisrael, as the river Nile. He points out that they were unfamiliar with the geographical reality, due to their living in Europe:

שו"ת רדב"ז חלק ו סימן ב אלפים רו

הרב המזרחי חשב כי נחל מצרים הוא הנילוס כאשר צייר באותה פרשה ואין לתפוס עליו לפי שהוא ז"ל צייר מה שלא ראה

If anyone has more examples of this phenomenon, please send them in.

2. I am pleased to report that the "Rationalist Medical Halachist" is back in action! Check out his website at

3. Dr. Marc Shapiro has a typically fascinating post, primarily about metzitzah, at the Seforim Blog. Also, there's interesting tidbits about the charedi world at The Jewish Worker.

4. My safari to Africa is filling up, but there are still some places left. Learn more about this trip of a lifetime at

5. If you live in NY/NJ, I'd appreciate it if you could help spread the word about my program at the Turtle Back Zoo and my lectures in NY.


  1. So what is the river of Egypt then?

  2. I saw the radvaz and ramban in intoduction to a book about archaeological discoveries regarding purim by landsman ?from beit shemesh?

    the ramban changes his mind about the location of rachel's burial place when he went to yerushalyim

  3. "another example of an early Acharon pointing to an inaccurate statement made by a Rishon"

    You have got to be kidding me. R' Eliyahu Mizrachi was only 39 years older than Radvaz. They either both rishonim or both achronim.

  4. I believe you have one example in the first perek of Gittin when it comes to Acco. On Daf 7b (if memory serves me correctly) Rashi locates it on the Eastern border of Israel.

  5. 24 years difference according to wiki
    The Radbaz was born in Spain around 1479
    Elijah Mizrachi (Hebrew: אליהו מזרחי) (c. 1455 – 1525 or 1526) was a Talmudist

  6. One need only look at the maps of Rashi, the Mizrachi, and so on to see their grasp of the geography of Israel wasn't that great. For example: The Dead Sea connects to the Red Sea.

    Ephrayim: The Radbaz is sometimes considered the first acharon, so technically it would be true. Only technically, as the Radbaz obviously wouldn't even know what a "Rishon" and "Acharon" were. Those terms were only invented years after the Acharon era was- retroactively, of course- determined to begin.

  7. elie

    Thus, it seems quite clear that the proper identification of Nehar Mitzrayim is Wadi el Arish (which is just south of the present day border of Israel with Egypt).

  8. pesach

    in the introduction to the above book
    he says as evidence that archeology is kosher he brings tosfos rid (without giving a source) that says to a torah scholar how wearisome to me are your words that acco is on the east, had you seen it as i have you would realise acco is on the west

    I could not find the tosfos rid though in gittin

  9. Obviously, R' Slifkin isn't merely looking for examples where one rabbi disagrees with another rabbi as far as geography or biology is concerned. For that, you can find hundreds of examples in the footnotes of R' Aryeh Kaplan's The Living Torah. R' Slifkin is looking for the explanations as to how one rabbi explains why another one is mistaken.

  10. @dovid Hebrew wiki say he was born in 1435. Anyhow the dates are not of importance.

    @Nachum I don't know who you are quoting. The division between rishonim and achronim is not clear. The most logical point of division is a significant event or change. Many have been offered such the Alhambra Decree or the finishing of the Shulchan Aruch.

  11. references of rishonim appearing to make scientific, including geographic, errors are easy to find - just read de rossi and etc.

    r slifkin is looking for something more specific: that one authority disagrees with another and says that the first authority erred because he didn't have visual access to the article in question. so far iirc there are only 3: olives, sugar, and the egyptian river.

    there is also chasam sofer siding with rambam about the prozdor, but i would assume rambam got his information from medical books which were based on autopsies.

    @elie - the egyptian river seems to be wadi el arish. RSG and, i beleive, kaftor vaferach say so explicitly.

    when ramban came to eretz yisrael he also saw the shekel and therefore decided like rashi regarding the size of the shekel. [comm. to chumash vol 2 p 507 in chavel edition, an appendix to the comm.; and כי תשא p 165 in toras chaim edition]

    regarding acco in gittin see r shurin's introduction to emess l'yaakov about when someone challenged the sugyah in gittin from the map, r yaakov's colleague refused to get involved but r yaakov patiently resolved all the difficulties.

    did rashi himself author the drawings found in his talmudic commentary? i would think not. they are found in maharshah and maharshal; seems that the printers copied them from there to the 'blatt' with rashi and added the word 'כזה'.


  12. If someone could locate the Tosafos Rid about Akko, that would be helpful.

  13. pliny
    when r. feinstein says regarding treifos that rashbo would have agreed today if he would seen the actuality.

    how one rabbi explains why another one is mistaken.

  14. pliny

    tosfos yomtov kilayim 5:5 says rash is wrong to contradict the experts in geometery and if he would have measured for himself he would have seen so.

    so how was he wrong he did not measure and did not believe in absolute proof of geometry

    הזאת. ואם הוקשה לו משנתינו לא ל׳׳ב
    מכחישי ופל רואיו יאמרו איט. אבל אץספק שלא פשה לו צורה מוחשת לראות מם שנים הסמוכים לי £ל העבר מזה ואל
    בה. שאילו היה רואה אין ספק שהיה חוזר מדבריו פי לא היה מכחיש גם החי


    tosfos yomtov kilayim 5:5 says rash was wrong about geometry because (1)he did not measure and (2)was not aware that the proofs of geometry are absolute

    אבל אץ ספק שלא פשה לו צורה מוחשת לראות
    שאילו היה רואה אין ספק שהיה חוזר מדבריו פי לא היה מכחיש גם החיש.
    כי לא אאמין שהיה החכם ז״ל משתבש בטעות המדברים מענין חטא החוש

  16. Tosfos Yom Tov Shviis 6:1 quotes the Kaftor Vaferach regarding the location of Akko and Kziv. He then says the Bartenura and Rash, who disagree, are wrong. "It is impossible to contradict reality, and all his (Kaftor Vaferach) words are through intense investigation. As he explains in his book, he carefully checked each place until he knew where each one was. It emerges that the Bartenura and Rash's words were just based on approximations and they did not get to the truth as it actually is."

  17. dovid -- great job! (Although it looks like my previous comment was addressing you, it was really just addressing the whole crowd.)

  18. the trumas hadeshen holds that a shaah zemanis is reckoned from dawn to nightfall and is 12 hours.

    I saw that an achron says about this that anybody who holds it is 12 hours from dawn to night (as opposed from netz to shkiah) lo mozo yodov ve'raglov in astronomy

  19. dovid said... I saw that an achron says...

    but who is this?

  20. reject

    cannot remember where I saw it.

    however the levush och: chapter 266 says about trumas hadeshen perhaps he did not learn astronomy books. (incidently a similar criticism is raised against the levush by the chidah in hilchos rosh chodesh when he explains a lunar eclipse)

    אלא שהתימה היותר גדול שעלי הוא מד ב ר י בעל תרושת הדשן סימן
    א' שדקדק בזה הענין ולא עלה על דעתו לחלק בזה אשר באמת הוא תמוה בעיני מאוד אבל אומר
    אני אולי היה זה לבלתי עוסקים בזמנו בספ*י התכונה וחשבו מאי דחלקו רבנן הייפ לעולם לי״ב שעית
    מתחיל לעולם מעלות השחר ער צאת הככבים ולדידי נראה לי מתו ר דברי התיעים האלקיים בפשיטות
    שטעות גמור דוא ילא היה דעת רז״ל מעולם רק מעת זריחת השמש ואיידי עד השקיעה תה נ״ל הלנה
    למעשי בכל הדינים הנאמרים במניין זה שתלו אותם בשעות היופנ״ל (

    (a reference to astronomy
    also in levush chapter 233
    ואילך דהיינו חצי שעה אחר חצי היום דו׳ שעות שאמדו בכ״מ ר״ל שעות זמניות
    היינו לפ• הזמן לפעמי׳ ארונו׳ ולפעמים קצרות שלעולם חלקו היום לי״ב שעות בין יום ארוך בין יום קצר
    וביום ארוך היי י״ב ישע-ת ארוטת וביום קצר י״ב שעו׳ קצרי׳ ונ״ל שר״ל י״ב שעית מעת זריחת השמש עד
    עת ( א ) השקיעה שבן הוא משמעו' כל ספרי התכונה ולפי זיז י י נ ו ר צ י וד־בה קו 1יות וספקו׳ שנפלו פפוסקיס
    בזמן תפלה זו ותפלת ערבית)

    also gra in och: chapter 459 that the opinion is a big mistake as all the astronomers say it is from netz to shkiah


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