The term “Rabbinic Judaism” is a misnomer, as there is no Judaism without the rabbis, just like there is no medical field without doctors and no court without judges. Thus, the term has no practical meaning and is not used by traditional Jews. However, since it has entered the common parlance, let’s discuss what people mean when they use it:

Rabbinic Judaism is generally defined as the beliefs and practices of the Jewish people, outlined in the Torah (Hebrew Bible) and interpreted by the sages (rabbis), incorporating oral traditions that have been handed down from Moses at Sinai.

In other words, any authentic element of Judaism that is not readily apparent when reading Scripture would be termed “Rabbinic.”

Moses

Along with the Written Torah, the kernel of the Oral Torah (which is often termed Rabbinic Judaism) was transmitted to us by Moses, who received it from G‑d Himself.

Read: What Is the Oral Torah?

Ezra the Scribe and the Men of the Great Assembly

Some of what we associate with Rabbinic Judaism can be traced to Ezra the Scribe, who led the building of the Second Temple in the 4th century BCE, and the body of rabbis he founded, known as “the Men of the Great Assembly.” Their contributions include the basic rubric of the daily prayers, the blessings said before eating, the holidays of Purim and Chanukah, and the formalization of the Biblical canon.

Read: What Are the Seven Rabbinic Mitzvahs?

Mishnah and Gemara

For a thousand years, the traditions of Rabbinic Judaism were carefully preserved and passed down orally from teacher to student. But in the chaotic years following the destruction of the Second Temple and the decimation of Jewish life in Jerusalem, it became apparent that some of these should be committed to writing. This gave birth to the Mishnah, the basic text of the Talmud, and Midrashim. In time, commentaries on the Mishnah, called Gemara, were added as well.

Read: 21 Talmud Facts

Challengers

Throughout the ages, there have been various challengers who questioned the authority and authenticity of the rabbi’s traditions and enactments and at times dismissed it as being merely “rabbnic.”

Sadducees: In the Second Temple era, the main opposition was from a group of elites (mostly priests) known as the Sadducees (Tzedukim in Hebrew), thus named because their leader was a priest named Tzadok. They are sometimes also named the Boethusians (Baitusim) after the group's co-founder, Bautus. While the group was at times a serious force within the Holy Temple, they had little influence over the masses and they faded to oblivion when the Temple was destroyed.

Karaites: Also known as Ananites, this splinter group was founded by Anan ben David in the 8th century. At times they included many accomplished scholars in their midst and were battled fiercely by defenders of traditional Judaism such as Rabbi Sadia Gaon, Rabbi Moses Maimonides, and others. With their origins and base in the Islamic world, the Karaites spread into Eastern Europe as well. Today, there are relatively few Karaite communities, mostly in Israel.

In the Modern Times: In the past several centuries, there have been various “movements” of Jews, each one wishing to reform or reshape Judaism into what they find palatable or inspiring, stripping away the time-hallowed traditions in favor of flashy fads, ranging from organ music in the 19th century to fanatical devotion to social activism in the 20th century.

Yet, throughout it all, authentic Jewish tradition (today known as Orthodoxy), as interpreted and preserved by the rabbis, continues its confident, upbeat, and Divinely-ordained march into the future.