These two schools had vigorous debates on matters of ritual practice, ethics, and theology which were critical for the shaping of the Oral Law and Judaism as it is today.
As stated in a notable Talmudic sugya, "Elu ve-elu, these and those are the words of the living God, but the Halakhah follows the School of Hillel."
(Eruvin 13b)[16] Accordingly, halachic-practice was decided in favor of Beit Hillel since they were agreeable and forebearing (or more literally, piteous).
The passage then says something which seems to imply that the position of the school of Shammai was accepted ("נמנו וגמרו נוח לו לאדם שלא נברא יותר משנברא").
Modern day Rabbinic Judaism almost invariably follows the teachings of Hillel, but there are several notable exceptions.
During the discussions Beit Shammai achieved a majority and were able to force all the remaining individuals to adopt a radically restrictive set of rules known as "Eighteen Articles"; later Jewish history came to look back on the occasion as a day of misfortune.
[34] Various explanations are given of the tragedy which justified fasting: bloodshed which killed 3,000 students;[35] or else the simple fact of the Torah being divided into two incompatible interpretations.
Together, they legislated many new enactments and passed new decrees, in an effort to ensure that the people of Israel not transgress the basic laws bequeathed to them by Moses.
"[38][39][40] Many of these rulings revolve around Israelites and their relationship to the priests who are required to eat their Terumah (Heave-offering) in a state of ritual purity.
Included therein are the prohibition of eating cheese produced by Gentiles, and the requirement of one who suffered a seminal or nocturnal emission (Hebrew: ba'al ḳeri) to immerse himself in a mikveh before reading from the Torah scroll, a ruling which was later rescinded, and the sweeping declaration that the lands of the Gentiles induce a defilement to any Jew that ventures therein.