Breaks In Tradition, Rabbinic Authority, and The Reasons For the Commandments

In Lawrence Schiffman's "Texts and Traditions: A Source Reader for the Study of Second Temple and Rabbinic Judaism." He brings up an idea about biblical interpretation that made me think about the oral tradition and whether it was a truly unbroken chain, given down from teacher to student, from Moses until today. First, let us look at the verses in the Torah that deal with the holiday of Succos (Vayikra 23:40-43):

מ  וּלְקַחְתֶּם לָכֶם בַּיּוֹם הָרִאשׁוֹן, פְּרִי עֵץ הָדָר כַּפֹּת תְּמָרִים, וַעֲנַף עֵץ-עָבֹת, וְעַרְבֵי-נָחַל; וּשְׂמַחְתֶּם, לִפְנֵי יְהוָה אֱלֹהֵיכֶם--שִׁבְעַת יָמִים.	40 And you shall take on the first day fruit of the beautiful tree, branches of palm-trees, and leaves of thick trees, and willows of the brook, and you shall rejoice before the LORD your God seven days.
מא  וְחַגֹּתֶם אֹתוֹ חַג לַיהוָה, שִׁבְעַת יָמִים בַּשָּׁנָה:  חֻקַּת עוֹלָם לְדֹרֹתֵיכֶם, בַּחֹדֶשׁ הַשְּׁבִיעִי תָּחֹגּוּ אֹתוֹ.	41 And you shall celebrate a celebration unto the LORD seven days of the year; it is a statute forever, for generations; In the seventh month you shall celebrate it.
מב  בַּסֻּכֹּת תֵּשְׁבוּ, שִׁבְעַת יָמִים; כָּל-הָאֶזְרָח, בְּיִשְׂרָאֵל, יֵשְׁבוּ, בַּסֻּכֹּת.	42 You shall dwell in booths seven days; all that are home-born in Israel shall dwell in booths;
מג  לְמַעַן, יֵדְעוּ דֹרֹתֵיכֶם, כִּי בַסֻּכּוֹת הוֹשַׁבְתִּי אֶת-בְּנֵי יִשְׂרָאֵל, בְּהוֹצִיאִי אוֹתָם מֵאֶרֶץ מִצְרָיִם:  אֲנִי, יְהוָה אֱלֹהֵיכֶם.	43 In order that your generations may know that I made the children of Israel dwell in booths when I brought them out of the land of Egypt: I am the LORD your God.

In the current tradition, we know that verse 40 is referring to the commandment of taking the Lulav

and Esrog. Therefore, we know these verses are teaching us that on Succos we have two main commandments, the taking of the Lulav with the Esrog and dwelling in booths. However, what if the interpretation of the verses was that the booths are to be made from the four species? What if these verses were all referring to only one commandment?

This is in fact what happened in the days of Ezra and Nechemia, at the beginning of the return of the exiles, according to Lawrence Schiffman. As it states in the book of Nechemia (8:14-17):

14And they found written in the Torah that the Lord had commanded, by the hand of Moses, that the Children of Israel dwell in booths on the festival in the seventh month.		ידוַיִּמְצְאוּ כָּתוּב בַּתּוֹרָה אֲשֶׁר צִוָּה יְהֹוָה בְּיַד מֹשֶׁה אֲשֶׁר יֵשְׁבוּ בְנֵי יִשְׂרָאֵל בַּסֻּכּוֹת בֶּחָג בַּחֹדֶשׁ הַשְּׁבִיעִי:
15And that they should announce and proclaim in all their cities and in Jerusalem, saying, "Go out to the mountain and bring olive leaves and leaves of oil trees, myrtle leaves, date palm leaves, and leaves of plaited trees, to make booths, as it is written."		טווַאֲשֶׁר יַשְׁמִיעוּ וְיַעֲבִירוּ קוֹל בְּכָל עָרֵיהֶם וּבִירוּשָׁלִַם לֵאמֹר צְאוּ הָהָר וְהָבִיאוּ עֲלֵי זַיִת וַעֲלֵי עֵץ שֶׁמֶן וַעֲלֵי הֲדָס וַעֲלֵי תְמָרִים וַעֲלֵי עֵץ עָבֹת לַעֲשׂת סֻכֹּת כַּכָּתוּב:
16And the people went forth and brought [these items] and made booths for themselves, each one on his roof and in their courts and in the courts of the House of God, and in the square of the Water Gate, and in the square of the Gate of Ephraim.		טזוַיֵּצְאוּ הָעָם וַיָּבִיאוּ וַיַּעֲשׂוּ לָהֶם סֻכּוֹת אִישׁ עַל גַּגּוֹ וּבְחַצְרֹתֵיהֶם וּבְחַצְרוֹת בֵּית הָאֱלֹהִים וּבִרְחוֹב שַׁעַר הַמַּיִם וּבִרְחוֹב שַׁעַר אֶפְרָיִם:
17And all the congregation of the returnees from the captivity made booths and dwelt in the booths, for they had not done so from the days of Joshua the son of Nun until that day, and there was exceedingly great joy.		יזוַיַּעֲשׂוּ כָל הַקָּהָל הַשָּׁבִים מִן הַשְּׁבִי | סֻכּוֹת וַיֵּשְׁבוּ בַסֻּכּוֹת כִּי לֹא עָשׂוּ מִימֵי יֵשׁוּעַ בִּן נוּן כֵּן בְּנֵי יִשְׂרָאֵל עַד הַיּוֹם הַהוּא וַתְּהִי שִׂמְחָה גְּדוֹלָה מְאֹד:

First, in this story there is no mention of the lulav and esrog, which one would expect to find if they are discussing how great the observance of the holiday was. Second, in verse 15 it seems like all the materials they are gathering is only for the building of the Sukkah, not the lulav. Lastly, verse 14 uses the language of "finding," which is used when something new is discovered. Had they possessed a tradition of how to celebrate the Succos holiday, the verse would not have used the language of "finding." Therefore, the Rabbis of the time interpreted the verse as they saw fit, and that is why this holiday was, seemingly, celebrated without the commandment of lulav and esrog.

But, perhaps Lawrence Schiffman is incorrect and his analysis is off base. Nevertheless, there are other examples in the bible that appear to say the traditions of Judaism do not proceed from Moses onward in an unbroken fashion. For example, in Kings II (22:8-14) it says:

8And Hilkiah the high priest said to Shaphan the scribe, "I have found the Scroll of the Law in the house of the Lord," and Hilkiah gave the scroll to Shaphan, and he read it.		חוַיֹּאמֶר חִלְקִיָּהוּ הַכֹּהֵן הַגָּדוֹל עַל שָׁפָן הַסֹּפֵר סֵפֶר הַתּוֹרָה מָצָאתִי בְּבֵית יְהֹוָה וַיִּתֵּן חִלְקִיָּה אֶת הַסֵּפֶר אֶל שָׁפָן וַיִּקְרָאֵהוּ:
9And Shaphan the scribe came to the king and brought back word to the king, and said, "Your servants have melted the silver that was found in the Temple, and they have given it into the hands of the foremen of the work who were appointed over the house of the Lord.		טוַיָּבֹא שָׁפָן הַסֹּפֵר אֶל הַמֶּלֶךְ וַיָּשֶׁב אֶת הַמֶּלֶךְ דָּבָר וַיֹּאמֶר הִתִּיכוּ עֲבָדֶיךָ אֶת הַכֶּסֶף הַנִּמְצָא בַבַּיִת וַיִּתְּנֻהוּ עַל יַד עֹשֵֹי הַמְּלָאכָה הַמֻּפְקָדִים בֵּית יְהֹוָה:
10And Shaphan the scribe told the king, saying, "Hilkiah the priest gave me a scroll," And Shaphan read it before the king.		יוַיַּגֵּד שָׁפָן הַסֹּפֵר לַמֶּלֶךְ לֵאמֹר סֵפֶר נָתַן לִי חִלְקִיָּה הַכֹּהֵן וַיִּקְרָאֵהוּ שָׁפָן לִפְנֵי הַמֶּלֶךְ:
11And it was when the king heard the words of the scroll of the Law, that he rent his garments.		יאוַיְהִי כִּשְׁמֹעַ הַמֶּלֶךְ אֶת דִּבְרֵי סֵפֶר הַתּוֹרָה ויִּקְרַע אֶת בְּגָדָיו:

Here again we have the language of "finding" which implies that some new information was presented. However, with this source we do not need to rely upon our own interpretation. The Radak explains what happened. Radak (verse 8):

ספר התורה מצאתי בבית ה׳. דרשו כי אחז שרף את התור׳ והטמינו מפניו ספר תורה אחת והטמינוהו תחת הנדבך ועכשיו מצא חלק׳ ספר התורה הזח ורחוק הוא זה שחזקיהו שבא אחריו שרבצ תורה בישראל איך לא הוציאו וכמה ספרי תורה הניח חזקיהו במיתו אלא מנשה מלך זמן רב שהרי מלך נ״ה שנה ועשה הרע בעיני ה׳ כתועבות הגוים ובנה מזבחות לע״ג בבית ה׳ ודוא השכיח התור׳ מישראל ואין פונה אליה כי כלם היו פונים אל האלהים אחרים ואל תקית הגוים ובנ״ה שנה נשתכחה התור׳
I found a Torah scroll in the house of G-D. The [background] explanation is that Achaz burnt the Torah and one torah scroll was hidden from him, out of sight. It was hidden under stone wall (or idolatrous temple area) and now Chilkiah found this torah scroll. This incident is difficult to understand, because Chizkiyahu, who came after [Achaz] disseminated Torah throughout Israel, so how could they not find this Torah. Also, how many Torahs did Chizkiyahu leave [in the midst of Israel] when he died? Rather, Menashe ruled for a long time, he was king for 55 years, and he did such evil in the eyes of G-D, like the wicked deeds of the nations, and built alters for idol worship. He caused Israel to abandoned the Torah and they did not turn to G-D, because all of them were turning to idols and to the ways of the nations. So, after 55 years, the Torah was forgotten. 

Here, we can see the Radak claiming that the tradition from Moses had been lost. Clearly, any oral tradition or explanation of the plain meaning of the written text was not found in these days. Thus, showing a broken link in the chain of a tradition from Moses.

This break in the link of tradition is not unique to biblical sources. In the Gemara, while speaking of the tradition of which plant is the Aravos (willow-branch) it states (Sukkah 44a):

 א׳׳ל ר׳ זירא לר׳ אבהו מי א״ר יוחנן הכי והא״ר יוחנן משום ר׳ נחוניא איש בקעת בית חורתן עשר נטיעות ערבה וניסוך המים הלכה למשה מסיני אשתומם כשעה חדא ואמר שכחום וחזרו ויסדום
R. Zera to R. Abbahu, Did R. Johanan really say this? Did R. Johanan not say in the name of R. Nehunya of the Plain of Beth Hawartan that ‘the law of the ten plants, the willow-branch and the water libation were given to Moses on Mount Sinai’? [The other] was appalled for a moment and then he answered, They were forgotten and then they were re-instituted.

Rashi here states:

  שכחום. בגלות בבל שכחו את התורה והמצות במקצת וזו נשכחה לגמרי.
They were forgotten: During the exile in Babylonia they forgot part of the Torah and the commandments and this [teaching of what the Aravos were] was completely forgot.

This idea is stated in other places in the Gemara as well. The following example is a discussion of when to use the closed form vs the open form of a letter (like a mem sofit vs a regular mem) (Shabbos 104a):

לא הוה ידעין הי באמצע תיבה הי בסוף תיבה ואתו צופים תקנינהו ואכתי אלה המצות שאין הנביא רשאי לחדש דבר מעתה אלא שכחום וחזרו ויסדום
People did not know which form came in the middle of a word and which one at the end, and the Watchmen came and ordained that the open forms should be in the middle of a word and the closed forms at the end. Still, [the text states] ‘these are the commandments’, which implies that no prophet is permitted to introduce an innovation hereafter? Rather, [we must say] this law [was in fact from heaven, but] was forgotten and the Watchmen established them again.

The point of this is to show that there is no unbroken chain from Moses to us with regards to the oral Torah. In fact, there are very few laws that were given over to Moses from Sinai. That is why the Gemara only has certain laws that we say they were a Halacha L'Moshe Mi'Sinai (A law given to Moses at Sinai from G-D). The rest of the laws are derived from logical discourse of the Rabbis.

There is no better illustration of this than the story of the Oven of Aknai (Babba Metzeia 59b) where there was a dispute between Rabbi Eliezer and the Rabbis:

וזה הוא תנור של עכנאי מאי עכנאי אמר רב יהודה אמר שמואל שהקיפו דברים כעכנא זו וטמאוהו תנא באותו היום השיב רבי אליעזר כל תשובות שבעולם ולא קיבלו הימנו אמר להם אם הלכה כמותי חרוב זה יוכיח נעקר חרוב ממקומו מאה אמה ואמרי לה ארבע מאות אמה אמרו לו אין מביאין ראיה מן החרוב חזר ואמר להם אם הלכה כמותי אמת המים יוכיחו חזרו אמת המים לאחוריהם אמרו לו אין מביאין ראיה מאמת המים חזר ואמר להם אם הלכה כמותי כותלי בית המדרש יוכיחו הטו כותלי בית המדרש ליפול גער בהם רבי יהושע אמר להם אם תלמידי חכמים מנצחים זה את זה בהלכה אתם מה טיבכם לא נפלו מפני כבודו של רבי יהושע ולא זקפו מפני כבודו של ר״א ועדיין מטין ועומדין חזר ואמר להם אם הלכה כמותי מן השמים יוכיחו יצאתה בת קול ואמרה מה לכם אצל ר״א שהלכה כמותו בכ״מ עמד רבי יהושע על רגליו ואמר לא בשמים היא מאי לא בשמים היא אמר רבי ירמיה שכבר נתנה תורה מהר סיני אין אנו משגיחין בבת קול שכבר כתבת בהר סיני בתורה אחרי רבים להטות
This was the oven of 'Aknai.  Why Aknai? Rav Yehuda said in Samuel's name: [It means] that they encompassed it with arguments as a snake, and proved it unclean. It has been taught: On that day R. Eliezer brought forward every imaginable argument, but they did not accept them. He said to them: 'If the halachah agrees with me, let this carob tree prove it!' Thereupon the carob tree was torn a hundred cubits out of its place. Others say, four hundred cubits. 'No proof can be brought from a carob tree,' they retorted. Again he said to them: 'If the halachah agrees with me, let the stream of water prove it!' Whereupon the stream of water flowed backwards. 'No proof can be brought from a stream of water,' they rejoined argued. Again he urged: 'If the halachah agrees with me, let the walls of the schoolhouse prove it,' whereupon the walls inclined to fall. But R. Joshua rebuked them, saying: 'When scholars are engaged in a halachic dispute, how can you interfere?' So they did not fall, in honor of R. Joshua, nor did they resume the upright, in honour of R. Eliezer; and they are still standing this way. Again he said to them: 'If the halachah agrees with me, let it be proved from Heaven!' Whereupon a Heavenly Voice cried out: 'Why do you dispute R. Eliezer, seeing that in all matters the halachah agrees with him?!' But R. Joshua arose and exclaimed: 'It is not in heaven.' What did he mean by this? R. Jeremiah said: The Torah had already been given at Mount Sinai; we pay no attention to a Heavenly Voice, because you have already written in the Torah at Mount Sinai, After the majority must one incline.

This story teaches us something incredible, that it doesn't matter what G-D originally intended for the Halacha to be, rather it only matters how the Rabbis interpret the Torah. The tradition that we have is not an unbroken chain of what G-D said to Moses, but of the leadership of the Rabbis telling us what they think the law should be based on the written word using their logic.

This idea is not new, in fact, it is stated straight out in the bible itself (Devarim 17:9-11):

9And you shall come to the Levitic kohanim and to the judge who will be in those days, and you shall inquire, and they will tell you the words of judgment.		טוּבָאתָ אֶל הַכֹּהֲנִים הַלְוִיִּם וְאֶל הַשֹּׁפֵט אֲשֶׁר יִהְיֶה בַּיָּמִים הָהֵם וְדָרַשְׁתָּ וְהִגִּידוּ לְךָ אֵת דְּבַר הַמִּשְׁפָּט:
10And you shall do according to the word they tell you, from the place the Lord will choose, and you shall observe to do according to all they instruct you.		יוְעָשִׂיתָ עַל פִּי הַדָּבָר אֲשֶׁר יַגִּידוּ לְךָ מִן הַמָּקוֹם הַהוּא אֲשֶׁר יִבְחַר יְהֹוָה וְשָׁמַרְתָּ לַעֲשׂוֹת כְּכֹל אֲשֶׁר יוֹרוּךָ:
11According to the law they instruct you and according to the judgment they say to you, you shall do; you shall not divert from the word they tell you, either right or left.		יאעַל פִּי הַתּוֹרָה אֲשֶׁר יוֹרוּךָ וְעַל הַמִּשְׁפָּט אֲשֶׁר יֹאמְרוּ לְךָ תַּעֲשֶׂה לֹא תָסוּר מִן הַדָּבָר אֲשֶׁר יַגִּידוּ לְךָ יָמִין וּשְׂמֹאל:

Rashi on verse 11 here even tells us (from chabad.org):

either right or left,: Even if this judge tells you that right is left, and that left is right. How much more so, if he tells you that right is right, and left is left!- [Sifrei]

ימין ושמאל: אפילו אומר לך על ימין שהוא שמאל ועל שמאל שהוא ימין, וכל שכן שאומר לך על ימין ימין ועל שמאל שמאל:

To further drive home this point, I will bring in the Rambam in the Sefer HaMitzvos (312th negative commandment):

The 312th prohibition is that we are forbidden from disagreeing with the Sages who pass down the Oral Tradition (may they rest in peace), or from deviating from any of their instructions in Torah matters. The source of this prohibition is G‑d's statement (exalted be He), "Do not stray from the word that they declare to you."

And the 174th positive commandment:

The 174th mitzvah is that we are commanded to obey the Beis Din HaGadol and act in accordance with all their instructions regarding what is prohibited and what is permitted. There is no difference whether it is something they received by Oral Tradition; derived using one of the principle of Torah extrapolation; decreed in order to correct some laxity or in response to some other situation where they found it appropriate and that it would strengthen Torah observance. We are required to obey all such directives and to act in accordance with their words, not to transgress them.The source of this commandment is G‑d's statement (exalted be He), "You must keep the Torah as they interpret it for you [and follow the laws that they legislate for you]."

The Rambam is telling us that the Rabbis are the keepers of the tradition and that, although there is no unbroken chain for all the laws, there is an unbroken tradition of following the great Rabbis of the generation. Those are our leaders and they are the ones we must follow.

Still, why would G-D set up our religion in this manner? Are we not looking for the truth? Don't we want to know what G-D actually said to Moses? This setup seems to be telling us that G-D's original intention when giving the commandments to Moses is irrelevant. So then, what is the purpose of giving the Jewish people the commandments?

There is an argument in Babba Metzeia (115a) that is based on whether the commandents have reasons behind them (like to make us better people) or if they are just for us to perform because G-D told us to perform them:

 אלמנה בין שהיא ענייה בין שהיא עשירה אין ממשכנין אותה שנאמר לא תחבול  בגד אלמנה: גמ' ת״ר אלמנה בין שהיא ענייה בין שהיא עשירה אין ממשכנין אותה דברי ר׳ יהודה ר״ש אומר עשירה ממשכנין אותה ענייה אין ממשכנין אותה שאתה חייב להחזיר לה ואתה משיאה שם רע בשכנותיה למימרא דר׳ יהודה לא דריש טעמא דקרא ור״ש דריש טעמא דקרא והא איפכא שמעינן להו דתניא ולא ירבה לו נשים ר׳ יהודה אומר מרבה הוא ובלבד שלא יהו מסירות את לבו ר״ש אומר אפילו אחת והיא מסירה את לבו ה״ז לא ישאנה א״כ מה ת״ל ולא ירבה לו נשים אפילו כאביגיל לעולם ר׳ יהודה לא דריש טעמא דקרא ושאני הכא דמפרש קרא ולא ירבה לו נשים ולא יסור מאי טעמא לא ירבה לו נשים משום דלא יסור ור״ש מכדי בעלמא דרשינן טעמא דקרא לכתוב רחמנא לא ירבה ולא בעינן לא יסור ואנא ידענא מאי טעמא לא ירבה משום דלא יסור לא יסור דכתב רחמנא למה לי אפילו אחת ומסירה את לבו הרי זה לא ישאנה:
MISHNAH. A MAN MAY NOT TAKE A PLEDGE FROM A WIDOW, WHETHER SHE BE RICH OR POOR, FOR IT IS WRITTEN, THOU SHALT NOT TAKE A WIDOW'S RAIMENT TO PLEDGE. GEMARA. Our Rabbis taught: Whether a widow is rich or poor, no pledge may be taken from her: this is R. Judah's opinion. R. Simeon said: A wealthy widow we take pledges from, but not a poor one, for you are bound to return [the pledge] to her, and you bring her into disrepute among her neighbors. Now, shall we say that R. Judah does not interpret the reason of the Writ (reason for the commandments), while R. Simeon does? But we know their opinions to be the reverse. For we learned: Neither shall he multiply wives to himself, [that his heart turn not away]; R. Judah said: He may multiply [wives], providing that they do not turn his heart away. R. Simeon said: He may not take to wife even a single one who is likely to turn his heart away; what then is taught by the verse, Neither shall he multiply wives to himself? Even such as Abigail! In truth, R. Judah does not Interpret the reason of Scripture; but here it is different, because Scripture itself states the reason: Neither shall he multiply wives to himself, and his heart shall not turn away. Thus, why ‘shall he not multiply wives to himself’? So ‘that his heart turn not away.’ And R. Simeon [argues thus]: Let us consider. As a general rule, we interpret the Scriptural reason: then Scripture should have written, ‘Neither shall he multiply [etc.].’ but ‘and his heart shall not turn away’ is superfluous, for I would know myself that the reason why he must not multiply is that his heart may not turn away. Why then is ‘shall not turn away’ [explicitly] stated? To teach that he must not marry even a single one who may turn his heart.

Here, the Gemara is introducing us to a fundamental argument, do the commandments have underlying LOGICAL reasons? Rebbe Shimon believes they do and Rebbe Yehuda does not. This leads to a statement made by Rambam (The Guide for The Perplexed in Part 3 Chapter 48):

When in the Talmud (Ber. p. 33b) those are blamed who use in their prayer the phrase, "Thy mercy extendeth to young birds," it is the expression of the one of the two opinions mentioned by us, namely, that the precepts of the Law have no other reason but the Divine will. We follow the other opinion [that the Laws have reasons].

The Rambam is telling us that, as a general rule, we follow the commandments and interpret them with the idea that they have underlying reasons, not just that G-D told us to do them. This is further elucidated by the Rambam (Guide for the perplexed Part 3 Chapter 31 Friedlander translation):

 There are persons who find it difficult to give a reason for any of the commandments, and consider it right to assume that the commandments and prohibitions have no rational basis whatever...  On the contrary, the sole object of the Law is to benefit us. Thus we explained the Scriptural passage, "for our good always, that He might preserve us alive, as it is this day" (Deut. vi. 24). Again, "which shall hear all those statutes (ḥuḳḳim), and say, surely this great nation is a wise and understanding people" (ibid. iv. 6). He thus says that even every one of these "statutes" convinces all nations of the wisdom and understanding it includes. But if no reason could be found for these statutes, if they produced no advantage and removed no evil, why then should he who believes in them and follows them be wise, reasonable, and so excellent as to raise the admiration of all nations? But the truth is undoubtedly as we have said, that every one of the six hundred and thirteen precepts serves to inculcate some truth, to remove some erroneous opinion, to establish proper relations in society, to diminish evil, to train in good manners or to warn against bad habits. All this depends on three things: opinions, morals, and social conduct. We do not count words, because precepts, whether positive or negative, if they relate to speech, belong to those precepts which regulate our social conduct, or to those which spread truth, or to those which teach morals. Thus these three principles suffice for assigning a reason for every one of the Divine commandments.

 The commandments are there to make us morally, socially and emotionally better people. This is why the Rabbis are given such great power over the law, because they are supposed to guide us as to how best to understand the laws in a way that will improve us and update our morals and social constructs with an evolving society. The best example of the Rabbis doing this can be found in the Gemara in Babba Kamma (83b):

אמאי?  עין תחת עין אמר רחמנא אימא עין ממש לא סלקא דעתך דתניא יכול סימא את עינו מסמא את עינו קטע את ידו מקטע את ידו שיבר את רגלו משבר את רגלו ת״ל מכה אדם ומכה בהמה מה מכה בהמה לתשלומין אף מכה אדם לתשלומין ואם נפשך לומר הרי הוא אומר לא תקחו כופר לנפש רוצח אשר הוא רשע למות לנפש רוצח אי אתה לוקח כופר אבל אתה לוקח כופר לראשי אברים שאין חוזרין
Why [pay compensation]? Does the Divine Law not say ‘Eye for eye’? Why not take this literally to mean [putting out] the eye [of the offender]? — Let not this enter your mind, since it has been taught: You might think that where he put out his eye, the offender's eye should be put out, or where he cut off his arm, the offender's arm should be cut off, or again where he broke his leg, the offender's leg should be broken. [Not so; for the Torah] comes to teach , ‘He that smiteth any man. . .’ ‘And he that smiteth a beast . . .’ just as in the case of smiting a beast compensation is to be paid, so also in the case of smiting a man compensation is to be paid. And should this [reason] not satisfy you, note that it is stated, ‘Moreover you shall take no ransom for the life of a murderer, that is guilty of death’, implying that it is only for the life of a murderer that you may not take ‘satisfaction’, whereas you may take ‘satisfaction’ [even] for the principal limbs, though these cannot be restored.’

Here we see the Rabbis using one of the logical principles for biblical exegesis to teach that a barbaric act, taking an eye for an eye, should not be followed. They instead reinterpret the verse in a non-literal way in order to morally improve this law. This could only be done if we believe that there are reasons for the commandments, because then man can use his logic to try and figure out the reason. With the goal being moral, social and emotional improvement, that Rambam tells us, the Rabbis can then interpret the law following these guidelines.  (Also, other laws that point out this idea are multiple wives and slavery that are no longer acceptable in Judaism)

Lastly, I want to share the words of the Meiri in his Sefer Hamidos: 

Fulfilling the Mitzvos (Commandments) with the intent that they are being performed to serve the creator is sufficient for the masses and the nation. However, it is proper for individuals to try and understand all that is possible, according to their capabilities, [with regard to what are the reason for the Mitzvos]. As it says in Psalms (119:66), "Teach me good reason and knowledge; for I have believed in Your Mitzvos (commandments)." What [Psalms] means is that even though I believe in Your Mitzvos and I fulfill all of the Torah, I request to know the reason and wisdom [behind] them. This is not in order to doubt the witnesses that have testified that these Mitzvos are true, because I already believe in them. Also, my belief (emunah) does not rely on the study of these things to the extent that if I found a good connection I would believe or if I found something I considered a lie I would deny them, because this is Kefira (Heresy) and a removal of the religion completely.

The Meiri points out that the most learned of the people (aka the Rabbis) should try and understand the reasons behind the commandments. The reason for this is clear now, the Rabbis need to understand the reasons for the commandments in order for them to interpret the law appropriately. The oral tradition is based on the guiding principle that the Rabbis will lead us to a morally, socially and emotionally improved law. There is no unbroken tradition that teaches us what G-D actually said at Sinai, because it doesn't matter. Lo bashamayim hi, it is not in heaven. The Rabbis are here to guide us in the principles of Judaism through the laws that they interpret in a manner that is forever being tweaked based on our improved understanding of the reasons for the commandments.