In The Subjunctive Mood in Arabic Grammatical Thought Arik Sadan outlines the grammatical theories on the nasb (subjunctive mood) in Classical Arabic. Examining over 160 treatises written by 85 grammarians, lexicographers and Qur?an commentators, the author defines and characterizes the opinions of medieval Arab grammarians concerning this mood in the verbal system of Classical Arabic. Special attention is given to the prominent early grammarians Sibawayhi (d. ca. 180/796) and al-Farra? (d. 207/822), who represent the Schools of al-Basra and al-Kufa respectively.The analysis of the grammarians' views enables the author to draw several important conclusions and hypotheses on the syntactic environments of the subjunctive mood, the dialectal differences relating to its employment and the historical changes and developments it underwent.