SOURCE: Davidson, Herbert A. Introduction to Averroes's Middle Commentary on Porphyry's Isagoge and on Aristotle's Categoriae, translated by Herbert A. Davidson, pp. xi-xxi. Cambridge, Mass.: The Mediaeval Academy of America, 1969.

In the following excerpt, Davidson discusses the philosopher Averroes's less than enthusiastic opinion of Porphyry's Introduction, which he commented on together with Aristotle's Categories. Davidson notes that Averroes pointed out the errors in Porphyry's work as an introduction to the study of logic.

By Averroes' time, eight of Aristotle's works had been grouped together to form a logical corpus, and Porphyry's Isagoge, strictly an introduction to the Categories, was added as a general introduction to the whole series. Thus the medieval Arabic Organon¹ contained nine works: the Isagoge, Categories, De Interpretatione, Prior Analytics, Posterior Analytics, Topics, De Sophisticis Elenchis, Rhetoric, and Poetics. Averroes, who ranked Aristotle far above other philosophers,² devoted almost all of his commentaries to Aristotelian...