The paper analyses the argumentative strategies of the ancient commentators on Aristotle's Meta- physics A 9, A 6 and M 4 and the functions ascribed by them to Aristotle's doxographic reports and critique. In discussing the use made of concepts from the Categories in the critique of Platonic Forms the commentators elucidate the need for further differentiations for didactic pur- poses in the institutional context of the philosophical schools of late antiquity. By doing this, the paper argues, the commentators further develop Aristotle's own argumentative strategy when he transfers tools from his logical treatises into other contexts. The commentators's transfer of texts and conceptual tools into other textual contexts follows the skopos of enhancing understanding of the meaning of the Aristotelian text. These acts of transfer constitute a new textual context for the Aristotelian text commented upon, one that includes texts from Plato, Platonic sources, Aristotle himself and earlier or contemporary commentators, each of which has its specific ar- gumentative functions.