 Several elements are characteristic of Simplicius’ commentaries. All are lemmatised, that is, Aristotle’s (or Epictetus’) text is divided into smaller sections of text which are then commented upon, and the commentaries are introduced with prologues of varying lengths (see below for more details). The comments on a single lemma are sometimes subdivided into two sections, one which mainly comments on the philosophical content (theôria) and one which comments on single expressions or words (lexis). Such a distinction goes back to Proclus (Festugière 1963 [1971]). Since the commentaries are probably not written for teaching purposes (see  §1),  they are not structured according to “lessons” (praxeis), as was the usual practice in the Alexandrian school after Ammonius. Digressions or autonomous essays that interrupt the running commentary are also characteristic of Simplicius (see Golitsis 2008a and  §2.3 in the supplement “The Commentaries of Simplicius”).  Like Aristotle, Simplicius frequently integrates longer doxographies. At times, he approaches philosophical issues through the method of “difficulties and solutions” (aporiai kai luseis), which can frequently be found in Damascius, Simplicius’ teacher, and ultimately goes back to Aristotle (cf. Metaphysics Beta, with its long list of aporiai). From Iamblichus, Simplicius borrows the policy that each of Plato’s and Aristotle’s works should be explained by first establishing its main, overarching topics (skopos) which hold all the parts together: