Arabic logic is a philosophical tradition which has lasted from the mid-eighth century down to today. For many years, western study of Arabic logic tended to concentrate on the early parts of its history, especially on the Greek antecedents of Arabic logic, and on the writings of the foundational philosophers, Alfarabi (d. 950), Avicenna (d. 1037) and Averroes (d. 1198). Recently, however, there have been notable excursions beyond these areas of traditional concentration, and I make a special effort in this entry to mention the contributions of post-twelfth-century logicians to the philosophical resolution of disputed  points.[1] 