In this paper I present and discuss Alexander’s reading of Aristotle’s Topics. After an overview of Alexander’s take on Peripatetic logic and the Organon, I review Alexander’s agenda on the Topics, with an emphasis on the ‘gymnastic’ value of dialectical training. This evidence suggests that Alexander is worried that the Topics, with their focus on arguments based on endoxastic premises, might not be thought worth studying. I therefore discuss Alexander’s account of endoxa against the backdrop of Hellenistic debates about the status of doxa (‘opinion’) and of what is ‘persuasive’ (pithanon) with respect to knowledge and what is ‘true’ (alethes). Alexander’s account rests on his views on the development of rationality, which I sketch based on Alexander’s treatise On the Soul. Such views might explain why Alexander does not seem to be worried by the possibility that the dialectical practice of arguing pro and contra any given thesis might lead to scepticism. Finally, I review some further evidence on Alexander’s practice of teaching philosophy through Aristotle’s works, and I suggest that Alexander’s way of reading and using the Topics may have left more traces in the later tradition than has been appreciated so far.