Rabbi Stuart Gershon has written a thorough exploration of the Jewish prayer service and ritual known as Kol Nidrei. A moving and dramatic synagogue service that inaugurates Yom Kippur, it is known by most Jews but is widely misunderstood. Jewish tradition is grounded in the seriousness of the power of the spoken word and may be understood only within that framework. Kol nidrei is viewed as a vehicle through which absolution is automatically granted for unfulfilled vows. Rabbi Gershon demonstrates that kol nidrei functions as a remedy for this grave problem of unfulfilled vows. The spoken word takes on a reality independent of human control, and no vow already in force can be revoked. Only by means of a legal fiction, whereby the retroactively annulled vow is treated as if it had never taken shape, can the vower be spared the grave consequences of an unfulfilled vow. Kol nidrei is the formula for one such legal fiction. The first book-length study of its kind, this volume explains the origins and halakhic basis of kol nidrei; details the debates concerning kol nidrei over the centuries; illustrates the way kol nidrei functions in modern times; provides appendices, variant texts, and musical arrangements; and investigates thoroughly the powerful ritual of kol nidrei.
This book seeks to trace the history of the Kol Nidrei, a Yom Kippur prayer seeking annulment of vows. The first known use of this prayer was in 9th-century Iraqi siddurim (prayerbooks). Gershon notes that the language of the Kol Nidrei is suspiciously similar to incantations designed to protect the user from demons, and suggests that the Kol Nidrei may have evolved from such incantations. (In fact, he writes that some commentators think that Kol Nidrei actually was at first intended as a magical incantation- but I wasn't persuaded by this view).
In any event, most leading rabbis of the Gaonic (9th-10th century) period opposed the Kol Nidrei, because the Talmud's provisions allowing annulment of imprudent vows do not on their face appear to allow annulment merely through public prayer. Nevertheless, the Kol Nidrei continued to appear in siddurim. Medieval rabbis tried to merely narrow the Kol Nidrei's reach, by making clear that it did not apply to interpersonal conduct such as contracts and court testimony; this effort was mostly successful.
In the 19th century Reform rabbis (and even at least one major Orthodox rabbi, Samson Raphael Hirsch) occasionally sought to expel Kol Nidrei from Jewish liturgy, primarily because of concerns that non-Jews might misinterpret the prayer as allowing dishonest conduct. However, these efforts failed.
Gershon gets his major points across; however, this book does occasionally overestimate readers' cultural literacy (e.g. referring to the P-Source, J-Source, etc. without explaining the Documentary Hypothesis out of which these concepts arose) and at first was a bit hard to follow.