 Since the Categories is the first book of Aristotle’s which we encounter, and Aristotle’s school—the so-called Peripatetic—is one of the schools of philosophy, we ought first to say how and in how many ways the philosophical schools received their appellations. Secondly, what is the division of the Aristotelian writings, so that the class to which we shall assign the present work shall be clear. Third, whence should one begin [the study of] Aristotle’s writings? Fourth, what is the goal of Aristotle’s philosophy? Fifth, which things lead us towards this goal? Sixth, what is the form of the Aristotelian writings? Seventh, why did the Philosopher practise obscurity? Eighth, what must the exegete of accounts (logoi) such as these be like? Ninth, what kind of student should be accepted? Tenth, in the case of each Aristotelian treatise, how many main points (kephalaia) should be taken up, which are they, and for what reason? (Simplicius, In Cat. 3.18–29, translated by M. Chase)