The Meaning of al-jabr wa’l-muqiibalah z by zyxwvu GEORGE A. SALIBA* Introduction It is generally accepted that the word Algebra is derived from the title kitdb al-muhtaSar zyxwv f i hisdb al-jabr wa’l-muqcibalah (compendium of algebra) of the class&al treatise of Muhammad Ibn Miisa al-KhwFuizmi (d.c. 860 A.D.)1. But the meanings of the words jabr and muqdbalah zy are still un- certain2. The purpose of this paper is to investigate the etymology of the word Algebra (al-jabr), and the word muqc?baZahwhich is almost always asso- ciated with it as in the title of al-Khwbizds treatise. The word jabr (root zyxwv jubara) has a number of meanings in ordinary Arabic, two of which are relevant here. The first is “to reduce a fracture”3, while the second, which is more general, is “to force, to compel”4. The traditional interpretation has connected jabr with the fist meanings for two main reasons. First, the Arab commentators,who were not algebraists themselves, have hinted at this connections, and second, the interpretation has been justified on the basis of al-Khwbizmi’s general use of the word jabr. A different approach has connected the wordjabr with zyx a non-Arabic root’. The traditional interpretation may indeed explain satisfactorily the use of the wordjabr as a name of a specific mathematical operation, which will be discussed below. But a difficulty arises when this interpretation is applied to the discipline of algebra. Again, the Arab commentators have hinted at the possibility that algebra, as a science, may have taken its name from the predominant use of the operationjabr in that sciences. This has been accepted by Rosen9 in his pioneer work on al-Khw5rizmi’s algebra. zyxwvu * American University of Beirut and Dcpt. of Near Eastern Languages, University of California, Berkeley, California 94720.