Al-Farabl's writings on logic and the philosophy of language include both loose commentaries on the Aristotelian Organon and independent treatises. In the former category al-Farabl produced a full set of epitomes of the Organon, including, as had been the custom since the days of the Alexandrian commentators, Porphyry's Isagoge and Aristotle's Rhetoric and Poetics (al-Farabl 1959; 1971a; 1986-7) . H e also wrote a great commentary (sharh) on the De interpretatione (al-Farabl 1960a; 1981a). His epitomes are not detailed efforts at exegesis of the Aristotelian texts, nor mere summaries of them, but take their overall organization and inspiration from Aristotle while developing personal interpretations of Aristotelian logic and the school tradition that had developed from it. O f his more personal writings, the Kitab al-huruf ("Book of Letters", al-Farabl 1969b) and Kitab al-alfdz al-musta'malah fi'l-mantiq ("Book of Utterances Employed in Logic", al-Farabl 1968a) are also devoted in large part to logical and linguistic topics, emphasizing the need to understand the relationship of philosophical terminology to ordinary language and grammar. 5

One of the overriding concerns of al-Farabl's logical writings is to delineate precisely the relationship between philosophical logic and the grammar of ordinary language. The historical reality of the importation of philosophy into Arabic from a foreign language and culture, that of

ancient Greece, and the attendant difficulties created by the need to invent a philosophical vocabulary in Arabic, had made this issue of paramount importance for the earliest Arabic philosophers, including al-Farabl's own teachers and pupils. In addition to this, the linguistic focus of much of Aristotelian logic produced territorial disputes with the practitioners of the indigenous science of Arabic grammar, who were concerned that the philosophers' interest in Greek logic was nothing but an attempt to substitute the grammar of Greek for the grammar of Arabic. Al-Farabl's logical and linguistic writings represented one of the most systematic efforts to harmonize these competing approaches to the study of language.