The fifth volumes of the Shulkhan Arukh

The legal code known as Shulkhan Arukh, compiled by the great Sephardic rabbi Joseph Karo in the mid-1500s, is still the standard legal code of Judaism. When rabbis, particularly if they are Orthodox, are asked to rule on a question of Jewish law, the first volume they consult generally is the Shulkhan Arukh.

The Shulkhan Arukh is divided into four volumes: Orakh Hayyim, Yoreh Deah, Even Hazer, and Khoshen Mishpat.

A popular Jewish folktale tells of a young student who came to a prominent rabbi to be tested for ordination. The rabbi's first question was "Name the five volumes of the Shulkhan Arukh."

The student, thinking that the rabbi had made a slip of the tongue, named the four volumes, but the rabbi asked him to name the fifth.

"There is o fifth volume." the student said.

"There is indeed," the rabbi said. "Common sense is the fifth volume, and if you don't have it, all your rulings will be of no use, even if you know the other four volumes by heart".

Source: Jewish Literacy, R. Telushkin.