There are many disagreements about four ancient Jewish institutions: the Sanhedrin, the Men of the Great Assembly, the Pharisees, and the Sadducees. Put differently, no one knows the truth about these institutions, even though that for many Jews, the subject is profoundly important.
Jewish tradition supposes that the institution of the Sanhedrin began during the days of Moses, and famed Bible commentators such as Rashi ascribe some activities to this group during the biblical period. However, the name Sanhedrin is Greek, which together with the fact that no reliable evidence exists for the existence of the Sanhedrin before the Greek period in Israel, and it is not mentioned in the Bible, prompted scholars to date its origin to around 300 BCE. The Talmud states that the Sanhedrin was a court of law, a kind of Supreme Court composed of 71 members. Scholars recognize that writers of the New Testament did not know how the Sanhedrin functioned and depict it improperly in the New Testament. Christians say that Jesus was judged by a Sanhedrin one night, while Jewish law mandates that courts are not allowed to judge at night. The Sanhedrin probably ceased to exist when the temple was destroyed by the Romans in 70 CE.
Men of the Great Assembly
Unsubstantiated Jewish tradition supposes that the Men of the Great Assembly were a group of 120 scribes, sages, and prophets who composed, or edited some of the books of the Hebrew Bible. But many scholars are convinced that the institution never existed. It is also not mentioned in the Bible. Other scholars say that if the Men of the Great Assembly existed, it was probably a kind of kitchen cabinet for Ezra who lived around 400 BCE, or a kind of congress that Ezra formed, and which ceased to exist around 300 BCE when the institution of the Sanhedrin began.
Pharisees and Sadducees
There is also dispute about the Pharisees and Sadducees. Traditional Jewish sources say the Pharisees continued the Oral Tradition, also called Oral Law, that God gave to Moses at Mount Sinai, while the Sadducees deviated from past practices and insisted, they would only obey what is indicated in the Torah, not the Oral Law. They said the Oral Law was not true Judaism; it is a post-biblical invention, a reform of Torah Law.
My uncle Rabbi Dr. Sidney B. Hoenig addresses all of these problems and more in his superb scholarly studies in The Great Sanhedrin, Dropsie College, 1953 and in his The Era of the Second Temple, Shengold Publishers, 1974. Louis Finkelstein does so as well in Ha-Perushim ve-Anshe Knesset Ha-Gedolah, Jewish Theological Seminary, 1950. The English translation of Professor Finkelstein’s excellent book is “The Pharisees and the Men of the Great Assembly.” They contend that the Pharisees were a group that developed practices based loosely on interpretations of the Torah that generally liberalized Torah mandates. The Hebrew name Perushim means “separatist.” They separated from the Tzedukim, a name based on the word tzedek, meaning ‘righteous, called in English Sadducees, and can be defined as the righteous ones, those who adhered to the ancient traditions. Many Sadducees functioned in the temple, while the Pharisees were associated with the common folk.
Whichever view is accepted, is arguably irrelevant. Judaism today is clearly not Torah Law, but Rabbinical Law. Jews are told to obey what the rabbis taught, whether the Oral Law that they were taught was revealed by God at Sinai, or it developed over various times because of changed circumstances by the Pharisees and the rabbis who followed them.