Essay 10 of Proclus’ commentary focuses on one of the passages in Plato’s Republic that has generated the most scholarly controversy – the argument through which Socrates distinguishes genuine philosophers from pretenders to that title.1 This argument is a key part of Socrates’ response to the third and greatest of the three questions put to him by his friends: the question of how the ideal city-state might come about. Socrates’ famous answer is that philosophers must become rulers or rulers must take up philosophy (473d–e), and this answer, in turn, requires that we distinguish genuine philosophers from those who are simply in love with learning. Proclus characterises this distinction as one between philosophia and philomathia and for him, as for Plato, it is a matter of ontological commitment rather than temperament or motivation. Those who genuinely love wisdom are those who recognise the necessity of forms and are capable of coming to understand them (476a–b).