 In the same vein, al-Kulliyyāt is far from being a textbook (kunnāsh); it is rather written against the tradition of textbooks that prevailed in the art of medicine. It is a defense of the art of “syllogistic” medicine against experiential medicine. He says: “As for those who limit themselves to the method of the textbooks without knowing the universal method, they will certainly make mistakes, as do the doctors of our time. As for limiting oneself to universal matters, this may be possible if the doctor is very skilled. Therefore, one of the considered conditions of perfection in the arts is that the craftsman have the power to deduce what he needs to deduce” (Kulliyyāt VII.552). The status of experience in medicine is limited but not entirely excluded: “Once the universals of the art of medicine are acquired, one needs the experience from which particular premises are acquired in order to be used in each particular case. These premises cannot be written in a book, because they are unlimited” (Kulliyyāt VII.517). Ibn Rushd makes an exception, however, in criticizing the manuals and textbooks on medical particulars, for Abū Marwān Ibn Zuhr, whose al-Taysīr can be trusted because the particulars it contains conform to the universal teachings of theoretical medicine (Kulliyyāt VII.583).