 The texts of Abharî and Kâtibî were used in the madrasa by Sunnis and Shî‘îs (though the Shî‘îs turned to the texts of Tûsî and Hillî in the nineteenth century). But the tradition was much more dynamic than the entrenchment of these texts in the syllabus would suggest. First, whatever introductory texts were used in teaching the discipline, it is clear that students who were attracted to logic studied well beyond these texts with teachers at the madrasa who were often engaged to teach other subjects. Secondly, other places such as hospitals and observatories provided less formal venues for the advanced study of logic (see Endress 2006).