Laesio Enormis and the Talmudic Law of Ona'ah

Abstract

It is well-known that Jewish law forbids ona'ah “overreaching”; that is to say: the act of wronging a person by selling him an article for more than its real (market) value, or, conversely, purchasing from him an article for less than its real value (M. Bava Mezia 3.4, seq.). According to (anonymous—stam) Tannaitic halacha (law), the right to claim against ona'ah was always in the hands of the injured party, and whichever side constituted the injured party (be it the vendor or the purchaser), that side had the right to choose either to declare the transaction void, or to make up, or receive the difference (T. Bava Mezia 4.3). Another view, that of R. Judah (ha-Nasi, flor. c. 170–220), is however recorded. R. Judah states that regardless of which side is the injured party, the choice as to whether to annul the transaction or to settle the difference always lies in the hands of the vendor (B. Bava Mezia 50b, Y. Bava Mezia 4.3). This (minority) view was rejected in the Amoraic period by the great Palestinian scholar R. Johanan (flor. c. 250–79), so that the later halacha follows the anonymous (majority) Tannaitic ruling (Y. Bava Mezia 4.3).The degree fixed in Tannaitic sources for ona'ah was one-sixth (M. Bava Mezia 4.3, 7; T. Bava Mezia 3.9). That is to say, anything less than one-sixth above or below the market price was not considered ona'ah, and the transaction was valid, while one-sixth or more constituted ona'ah, invalidating the transaction, unless the injured party (stam) or the vendor (R. Judah) agreed to settle the difference.