1. Introduction: The authority of the Sages to establish laws
This discussion will deal with the authority of the Sages to create laws. Four issues will be discussed:
- From where do the Sages derive their authority to create new laws?
- What types of laws can the Sages create?
- Is their authority unlimited or is there a set of parameters within which they must operate?
- Can the laws created by the Sages be amended or appealed and if they are subject to review, under what circumstances?
These are the statutes and ordinances and laws, which Hashem made between Himself and the children of Israel at Mount Sinai by the hand of Moshe. (Sefer VaYikra 26:46)
Shavuot commemorates our acceptance of the Torah at Sinai. The Torah is composed of two components – the Written Law and the Oral Law. According to our tradition, the term “laws” – Torot – in the above passage includes both of these components. As the passage indicates, both were transmitted to Moshe at Sinai. The Sages are vested with enormous authority over the development and implementation of the laws of the Torah. In order to address the questions raised above, we must understand the nature and boundaries of this authority.
Maimonides discusses the authority of the Sages. Before considering his comments some background information is required. The Torah creates a system of courts. These courts adjudicate both civil and religious matters. These courts are organized in a hierarchal system. In ancient times the most authoritative court in this system was assigned to the Granite Chamber that was adjacent to the Bait HaMikdah – the Sacred Temple. Maimonides discusses the authority of this court and its Sages.
According to the law which they shall teach you, and according to the judgment which they shall tell you, you shall do. You shall not turn aside from the sentence which they shall declare unto you, to the right hand, nor to the left. (Sefer Devarim 17:11)
2. The source of the authority of the Sages
Maimonides explains that this court is the “root” or foundation of the Oral Law. He adds that the authority of the Sages is derived from the Torah itself. The above passage instructs us to follow the Torah as directed by the Sages. According to Maimonides, implicit in this directive is authorization of the Sages to provide direction in the proper observance of the Torah. This includes legislative authority.
The unique authority of the Sages and their highest court is in three areas:
- This court is the ultimate guardian of the Oral Law received as a tradition from Moshe. Its Sages are responsible for mastery and preservation of this tradition.
- This court is authorized to interpret the Written Law according to accepted principles of biblical exegesis.
- This court is empowered to create new laws designed preserve and reinforce the mitzvot of the Torah.
In other words, this court is empowered to create new laws. These laws are an expression of either one of two of the areas of authority outlined above. A new law may be enacted by the Sages in order to protect the laws of the Torah. Alternatively, a new law may be derived by the court from the Written Law based upon the established principles of biblical interpretation.
3. The types of laws established by the Sages
Let’s consider examples of laws created by the Sages. On Shabbat it is prohibited to perform melachah. Melachah is any one of thirty-nine forms of creative work. In order to violate the Torah prohibition, the melachah act must be personally performed. If one directs a non-Jew to perform the melachah act on one’s behalf the Torah prohibition is not violated. The Sages established a prohibition against directing a non-Jew to perform melachah on one’s behalf. The Sages reasoned that the Torah’s prohibition against performance of melachah would not be sustained if it could be easily circumvented through enlisting a non-Jew to perform the melachah on one’s behalf. This is an example of a law enacted by the Sages in order to protect the laws of the Torah.
Let’s consider another law enacted by the Sages. The Torah’s laws include the institution of marriage. Marriage begins with betrothal – kiddushin – and is completed by the bride and groom beginning their lives together. The Torah establishes multiple means of betrothal. For example, betrothal can take place through a written marriage contract. Maimonides explains that another method of betrothal is through the groom presenting his bride with money or an object of value in exchange for her agreement to marriage. Maimonides adds that this method of betrothal was established by the Sages. This is the method of betrothal that is used in our times. When the groom places a ring on the finger of his bride and announces that with the ring he betroths her, this method of betrothal is employed.
The Talmud explains that the suitability of money or an object of value for betrothal is derived through the interpretation of the relevant passages in the Torah. This means that this method of betrothal is authorized by the Torah. Yet, Maimonides states that this method was established by the Sages. Can Maimonides’ assertion be reconciled with the Talmud’s contention that this method is derived from the Torah itself?
In fact, these two characterizations are completely consistent. The Sages are empowered to interpret the Torah and derive from its passages new laws based upon the established principles of biblical exegesis. The Sages discover or derive these laws. However, they are derived from the Torah and it is the Torah that is the legislating authority. It is correct to say that such laws are established by the Sages and also, derived from the Torah.
4. Parameters of the authority of the Sages
These two areas of authority establish clear parameters of authority. The Sages may create laws that are derived from the Torah itself. They may also create laws that reinforce the Torah. A law that is not included in and derived from the Torah or does not reinforce a Torah law is beyond the purview of Sages and exceeds their authority.
There are a number of fundamental differences between laws that are derived by the Sages from the Torah and laws that the Sages create to reinforce the laws of the Torah. One well-known difference is in regard to stringency with which these laws are treated. A higher degree of stringency is required in observance of laws that are derived from the Torah and a lesser degree is required in regard to laws created as reinforcements.
5. The repeal or amendment of laws created by the Sages
Maimonides describes another difference that is counterintuitive. He explains that a law created by the Sages as a safeguard to the laws of the Torah cannot be easily repealed. Once such a law is established it can only be repealed by a subsequent court whose Sages are greater than those of the court that created the law. They must also represent a generation of Sages more numerous than the generation of Sages creating the law. 
This requirement does not apply to a law established by the Sages through a process of biblical exegesis. Such a law may be repealed by any subsequent court – even one whose Sages are inferior in scholarship to those who established the law. 
Paradoxically, in this respect a law that is created by the Sages is more stringent than one derived from the Torah. A law that the Sages derive from the Torah can be revoked by any subsequent court. A law created by the Sages as a reinforcement can only be retracted by a court that is greater than the one establishing it. How can this paradox be explained?
The key to the resolution of this paradox is to understand the authority that is the foundation of each of these laws and to identify the role of the Sages in the creation of the law. In the instance of a law created by the Sages as a reinforcement of the Torah, the foundational authority upon which the law rests is that of the Sages who created the law. These Sages exercise their authority to legislate in creating such laws. Because their authority is the foundation of the enactment, only a court with greater authority can revoke the law. Greater authority is only deemed present when the subsequent court exceeds the prior in the wisdom of its Sages and in the number of Sages that the court represents.
When the Sages derive a law from the Torah, the law’s foundation is not the authority of the Sages. The law is authorized by the Torah itself. The Sages are merely acting as a “catalyst”. They discover the intent of the Torah. They are not legislating; they are interpreting. Because they are not legislating, the law is not founded upon their authority. Each generation’s qualified Sages are entrusted with the role of interpreting the Torah. Moshe’s interpretations and those of a court in a latter century have the same veracity.
An analogy will help illustrate this idea. An executive in a large corporation decides to assign a task to a subordinate. He assigns the task and the subordinate engages himself in executing the assigned task. A day later the subordinate receives a directive from another executive directing him to abandon the task. He then approaches the executive who assigned the task to confirm that he should now abandon it. The executive tells him that he wants him to complete the task. Now, the subordinate is confronted with two contrary directives. One executive has assigned him a task to complete; another has directed him to disregard the task. What should the subordinate do?
This dilemma may be easily resolved. If the executive assigning the task is subordinate to the executive who has canceled the assignment, then the assignment is canceled. If the executive canceling the task is subordinate to the executive who assigned the task, then the task must be completed. In other words, each directive is founded upon the authority of the executive who assigned it. The directive that rests upon a foundation of higher authority must be followed.
However, let’s consider a slightly different case. An executive sends his assistant to a subordinate with a message. The message includes a task that it assigns to the subordinate. The next day the executive changes his mind and decides to cancel the directive. His assistant is not available to deliver the cancelation to the subordinate. He summons his secretary and directs him to carry the cancelation message to the subordinate. The subordinate receives the message. He is not confused. He understands that the task was originally assigned to him but the circumstances have changed and now the assignment is canceled. He is not at all confused by the fact that the initial message with the assignment was delivered by a member of the executive’s office with higher authority and the cancelation was delivered by a staff person with less authority. He understands that the assignment and its cancelation are founded upon the authority of the executive and that the manger has many staff people in his office that he may employ to deliver messages.
Each of these little vignettes is analogous to one of the types of laws established by the Sages. The first vignette is analogous to a law that is created by the Sages as a reinforcement of a Torah law. This law is founded upon the authority of the court that creates it. Like the directive in the analogy, it can only be canceled by greater authority. In the case of a law created by the Sages, this greater authority is a court of greater stature.
The second vignette is analogous to a law that the Sages derive through interpretation of the Torah’s passages. In this instance the role of the Sages is similar to that of the office staff person delivering messages for the executive. The veracity of assignments does not rest upon the authority of the assistant or secretary. Neither does the veracity of the law derived from the Torah rest upon the authority of the court that interprets the Torah. The law is founded upon the authority of the Torah itself to legislate. The court that interprets the Torah and derives the law serves an only intermediary function. Therefore, any court may amend or revoke a law that a prior court derived through biblical interpretation. The court is akin to the staff person. It is not the source of authority that authorizes the law. The court merely discovers and communicates the message in the Torah. Rabbaynu Shlomo ben Yitzchak (Rashi), Commentary on Sefer VaYikra 26:46.  The members of this court are leading Sages. Their suitability for membership on the court is established through their smichah – ordination. This ordination is very different from the ordination of our era. Contemporary ordination signifies the recipient’s knowledge and qualification to provide an opinion regarding specific areas of halachah. The ancient ordination signified that the recipient was learned and expert in the Oral Tradition transmitted to him through a chain of scholars – similarly ordained – reaching back to Moshe. This ancient form of ordination is no longer in affect. Periodic efforts have been made to reestablish this form of ordination. None have been effective.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Mamrim 1:1-2.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Eyshut 1:2.  Mesechet Kiddushin 2a.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Mamrim 2:2.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Mamrim 2:1.