Ibn Wāṣil (d. 1298), perhaps better known today as a historian and an emissary to the court of King Manfred in southern Italy, was also an eminent logician. The present publication is a critical edition of his main work in the field, a commentary on his teacher Khūnajī’s (d. 1248) handbook al-Jumal. The work helped consolidate the logic of the “later scholars” (such as Khūnajī). It also shows that commentators did much more than merely explain the original work and instead regularly discussed and assessed received views. Ibn Wāṣil’s work was an influential contribution to a particularly dynamic chapter in the history of Arabic logic.

Khaled El-Rouayheb (PhD 2003), is Jewett Professor of Arabic at Harvard University. His monographs include Relational Syllogisms and the History of Arabic Logic, 900–1900 (Brill, 2010) and The Development of Arabic Logic, 1200–1800 (Schwabe 2019).

Students and scholars interested in Arabic and Islamic philosophy, Islamic intellectual history, and the history of logic will find this work especially valuable.