The ultimate aim of every linguistic tradition is to go beyond the purely descriptive level and seek an explanation for linguistic phenomena. Traditions differ, however, with regard to the class of linguistic phenomena they wish to explain and the framework in which they define their explanation. In this volume the English translation is presented of the treatise on linguistic explanation by the 10th-century Arab grammarian az-Zaggagi, one of the most original thinkers of the Arabic tradition. He worked in a period in which the influence of Greek logic and philosophy made itself felt in almost