Shattering Presence: Being as Change, Time as the Sudden Instant in Heidegger's 1930–31 Seminar on Plato's Parmenides

The importance of Plato for Martin Heidegger's interpretation of the history of metaphysics is now well known and documented. However, what is arguably his most radical interpretation of a Platonic dialogue, a 1930–31 seminar on the Parmenides, remains largely unknown and for two reasons. First, while Heidegger's notes were published in 2012 as part of the Gesamtausgabe (vol. 83), they are brief, cryptic, and cover barely half the seminar. We know this because a detailed and complete transcript is preserved in the Marcuse Archive in Frankfurt am Main, a transcript ignored by the editor of GA83 and not previously explored in significant detail. Second, Heidegger preserved a puzzling silence elsewhere about the seminar's findings (which undermine his narrative about the history of metaphysics). The present paper seeks to reconstruct the argument of the seminar both for its insight into the special role played by the 'third' hypothesis in the deductions of the second half of the Parmenides and for the light it sheds on Heidegger's unfinished Auseinandersetzung with Plato.