1. Lesley Brown (University of Oxford), 26.2.2025

Title: Ousia and einai in Republic V-VI Research Centre for Greek Philosophy, Academy of Athens Philosophy Series 2025: Plato’s Republic V-VII Organizers: Alexander Nehamas, Thanassis Gkatzaras, Xanthippe Bourlogianni Location: Elli Lambridis Philosophical Library, Athens ABSTRACT: Plato’s choice of ‘being’ (to on, ta onta, ousia) to designate his Forms, i.e. the higher tier of reality, was no doubt influenced in large part by Parmenides. For the abstract noun ousia, (hitherto used for wealth, possessions) Plato signalled a novel use to mean essence, what it is, in Euthyphro and Meno, and then plainly introduced (in Phaedo) a further use of ousia to signify the Forms. Many (but not all) of the uses of ousia in Republic are likewise used to designate the higher tier of reality (the Forms) or their mode of being. Does Plato ever indicate as clearly how he is using einai, on? When to on designates a Form, or the realm of Forms, and when Forms are described as ‘being more’ (mallon onta) does Plato make clear how these should be understood? I revisit the well known issue of how to understand all the moves invoking being and not being in Republic V’s second argument for the difference between gnōsis and doxa. I offer a few revisions to an earlier proposal about how the different uses of the verb ‘to be’ in Greek are related (Brown, L., (1994), ‘The verb ‘to be’ in Greek philosophy: Some Remarks’, in S. Everson (ed.), Companions to Ancient Thought, iii: Language). One way Plato does signal an important use of the verb ‘to be’ is when he designates a Form as ‘ho esti’, [‘what it is’ OR ‘what is …’], drawing attention to the locution at 507b6 and thereby reminding the reader of Phaedo 75d. I explore how this phrase should be understood, and draw some conclusions about the relative importance, and import, of the variations in derivatives of ‘being’ or ‘to be’ as used in connection with the higher tier of reality.