Science vs Chazal? Ra'avad vs Rambam. An interesting case and a lesson.

One of the enjoyable things that one encounters when learning Mishne Torah, are the sharp comments Ra’avad makes when he disagrees with Rambam. For whatever reason, whether it was customary for scholars to use sharp language when disagreeing or that Ra’avad wanted to bring Rambam down a peg for ideological reasons[1], they show that he had a sharp wit and a good sense of humor. While learning Hilchot Kilayim I came across one of the most explicit and, to my mind, interesting ones that shed light on the reality the Rishonim confronted when dealing with texts and their reaction. I will not go into the minute details of the Halacha just enough so that the exchange can be understood.

If one plants grain or vegetables in a vineyard, one draws a circle of 16 Amot around the grain and all vines within that circle are forbidden and must be destroyed. The Mishna in Kilayim 5:5 however gives the number of vines in the forbidden area. It says that if the vines are spaced at four or five Amot intervals a total of 45 trees will have to be destroyed. The Rishonim could not make headway on this Mishna. How could there be the same 45 trees whether they are spaced four or five Amot apart? In addition what is the meaning of giving the number of trees?

In an uncharacteristic long Pirush Hamishna Rambam explains that as in a spacing of five Amot the edge of the circle would pass beyond the last tree inside it and there will be exactly four or less Amot between the circle and the next tree. The next tree or trees are therefore also included in the prohibited batch as a vineyard includes space to work the vines which is four Amot. As the circle is expanded to the additional vines, 45 vines are included. (In the printed Mishnayot Rambam’s drawings are included.) Thus the Mishna was teaching us that one has to add any vine that is within 4 Amot from the circle. In fact that is what Rambam rules in MT.
רמב"ם הלכות כלאים פרק ו הלכה


במה דברים אמורים כשהיה בין שפתי העיגול הזה ובין שורות הגפנים שחוצה לו יותר על ארבע אמות, אבל אם היה ביניהם ארבע אמות מצומצמות או פחות רואין את העיגול כאילו הגיע לשורה הסמוכה לו וכאילו רוחב העיגול ארבעים אמה ורואין כל גפן שתפול בתוך עיגול זה של ארבעים אמה הרי היא מתקדשת

(I am too lazy to translate so those who have difficulty with the Hebrew trust me that is what he says). There is no need to discuss the 45 trees in the Halacha as it is incidental.

Rambam ends his discussion in Pirush Hamishna with the following comment:

וביארנו טעם כל זה. וכבר נתבארו עניני הלכה זו כולם בעז"ה. התבונן בהם היטיב, לפי שכשנשאל עליה רב מרבני התלמוד היתה תשובתו אחרי גמגום, ויש בדבר דקדוקין הרבה ואחרי כן יסייעו מן השמים ונצוה לפרשהו לכם.
We explained all the reasons [of this Mishna] and this Halacha was clarified with the help of God. Contemplate them [these halachot] well because when one of the Talmudic experts was asked to explain it his answer was obfuscating and there are many questions with his approach. [I am not sure how to translate the last few words so here is my best guess.]Thereafter heaven helped and we were ordered to explain it to you.

Ra’avad did not see the Pirush Hamishna. All he had is the Mishna and Rambam’s ruling about the additional four Amot that reach the next row of vines.

+/השגת הראב"דא"א כל מ"ש בכאן אין לו שרש בגמרא ולא בתוספתא ולא השכל מורה וחוץ לעיגול שלשים ושתים אמה למה יאסור כלל וחיי ראשי לולא כי מלאכה גדולה עשה באסיפתו דברי הגמרא והירושלמי והתוספתא הייתי מאסף עליו אסיפת עם וזקניו וחכמיו כי שנה עלינו הלשונות והמליצות וסבב פני השמועות לפנים אחרים וענינים שונים

All that he wrote here has no basis in Gemara or Tosefta nor does it make logical sense. Why should it be prohibited outside the circle that has a 32 Amot diameter? [IOW if the Halacha is that vines within a 16 Amot radius are prohibited why add on more?] By my head, if not for the fact [if I did not feel bad for him] that he put in a lot of work gathering the words of the Gemara, Yerushalmi and Tosefta, I would bring together a gathering of people and their elders and scholars [to protest!]. For he has changed the language and the euphemisms [Rambam does not repeat the Mishnayot verbatim] thus distorting their meaning into different directions. [Ra'avad proceeds to give his explanation of the Mishna].

Rosh (Rabbeinu Asher Ben Yechiel) came to Toledo, Spain from Germany in the 1300’s bringing with him the learning of the ba’alei hatosafot which included Rabbeinu Shimshon of Sens. Much was written about this Mishna especially by the latter in his Pirush on the Mishna. Here he had a Mesora from his Rebbis (including Ra’avad) and Rambam’s ruling but this time also his Pirush Hamishna (Rashba a friend and contemporary of Rosh had it translated. Rosh met him on his way to Spain and spent two weeks with him. What wouldn’t I give to have been a fly on the wall when this meeting occurred!) What does a seeker of the truth who is out of his depth do? (Rosh had no secular education. Furthermore, Northern Europe in those days was far behind Southern Europe especially Spain.) He asks an expert to look into it and report back. He therefore asked R. Yisrael ben Yosef (of the Yisraeli family who were known mathematicians? I am also not sure the name quoted here is correct.) to figure this out and tell him who is right.

.+
כסף משנה הלכות כלאים פרק ו הלכה ב

ומצאתי כתוב ששאל הרא"ש את ה"ר ישראל שהיה חכם בחכמות על דברי מי יש לסמוך והשיב לו כלשון הזה. אדוני ומרי תרב גדולתך כגודל כשרון פעולתך. עיינתי בפירוש משנת הנוטע ירק בכרם להר"מ ז"ל וראיתי כי הפליא עצה הגדיל תושיה בפירושה אבל נראה לי לפי עניות דעתי כי האריך בה הרבה והלשון אינו מחוור כפי הצורך כי נראה סתירה בדבריו למי שאינו מעיין בהם עיון דק. אבל כלם נכוחים למבין. והענין אין לנטות ממנו ימין ושמאל

. והנה פירשתים לפי דעתו ולא חדשתי בה כלום מלבי אלא קיצור הלשון ותיקונו
זהו מה שהבנתי מפירוש משנה זו מדברי רמז"ל והן הן הדברים שנאמרו למשה בסיני. ואל יתפתה אדוני ומורי במ"ש רבינו שמשון ז"ל בפירוש משנה זו ואל תשגיח עליו כלל כי חוץ מכבודו הוא שבוש נטוי על קו תוהו ואבני בוהו לא זה הדרך ולא זו העיר. ומה שכתב בשם חכמי המדות הוא אמת. ומ"ש ז"ל כי ברבוע שארכו יותר על רחבו אין על דבריהם הוכחה. יש ויש. ומה שכתב ליתיה להאי כללא, איתיה על כל פנים. ויהי כנהר שלומך ויעמוד לעד זרעך ושמך, כחפצך וכחפץ צעיר תלמידיך נוגה חסדיך, ישראל בר יוסף נ"ע

I looked into Rambam’s Pirush on this Mishna and I saw that he had marvelous insights and shows great power [of intellect] in its explanation. At first blush they are hard to understand as he elaborates too much to the point he appears to contradict himself to someone who does not pay great detailed attention. However once understood one sees that he is correct. One may not stray left or right from his approach. [R. Yisrael then explains Rambam and finishes as follows:]

I explained the Mishna as I understood him [Rambam] and I have not added a single idea to what he said. Those are the words that Moshe received at Sinai. Do not be distracted my master with the words of Rabbeinu Shimshon explaining this Mishna. Do not pay attention to his words at all as they do not bring him honor. They are a mistake, resting on a vacuous line [of thought?] and nonsensical foundations [literally stones]. That is neither the way nor the city! What he wrote based on the Mathematicians is correct. [Apparently RS quoted Pi]. As to his claim that in a rectangle there is no proof that Pi applies, there sure is such proof. [To explain the Mishna apparently (I did not delve into it but assume) RS tried to argue that the ratio between a circle and a square is different!) His argument that it does not apply to a rectangle is incorrect. It does!


Here we have a fascinating situation. Ra’avad missed Rambam’s point completely and understandably as he did not have the Pirush Hamishna. Not seeing the brilliant insight he called him a gatherer! It is a put down saying that he has no original ideas and sometimes errs in understanding the texts! (Where was the Brisker Rav?!)

R. Shimshon was aware of Pi but as he could not understand the Mishna according to it, imagined a disagreement between Chazal and science on a basic mathematical theory. He found himself pushed into a corner and came up with the absurdity that Pi is not universal.

Rosh who was steeped in the Franco – German school of the Ba’alei Hatosafot, could not ignore his Mesora but at the same time felt compelled to find the truth. He asks help and gets it. When he writes his Pirush on Mishna he quotes the words of R. Yisrael. Truth is the ultimate arbiter!

Another important point is that people have a habit jumping to conclusions when they think they understand a Chazal and seemingly it disagrees with science or reality. Is it possible that the saying of Chazal had another meaning that was lost over time? Rambam clearly did rediscover the true meaning of this Mishna as he himself attributes it to God’s help. No one before him understood it and it was lost in the tribulations of Galut. In the upcoming Hakirah there is an article that does a similar thing with a different Gemara. Once you read it, a Gemara that was a thorn in the gut of all Meforshim, becomes clear like day.

As an aside, Rosh was not a great fan of secular knowledge. He did not accept Rambam’s philosophy and weltanschauung but when it came to truth he had no problem looking into the secular sciences and accepting reality. Not only in this case but also in general he asked members of the Yisraeli family to teach him the basic sciences that he lacked.


Shabbat Shalom.

[1] See his sharp comment in the introduction to MT.