The Theaetetus

Martin Heidegger’s analysis of Platos’ Theaetetus can be found in The Essence of Truth (Continuum, 2002). As the title suggests, Heidegger’s intention, in this work, is to address the theme of truth, in particular the Greek understanding of truth as aletheia, which means the unhiddenness of being.

The Essence of Truth is part of Heidegger’s project to bring into the open what he believes we have long forgotten, that is being, that which is present in addition to what is physically there. Heidegger proposes that this return to being be re-enacted by examining the essence of truth as aletheia. In order to do this aletheia itself must be put into question, by exploring what beings are prior to unconcealment, i.e. as hidden, as untruth – pseudos, the false. Therefore the title of Heidegger ‘s analysis of the Theaetetus, in the second part of The Essence of Truth: “an interpretation of Plato’s Theaetetus with respect to the question of the essence of untruth.”

The Theaetetus is constructed in the form of a dialogue, between Socrates and Theaetetus, and discusses the nature of knowledge. Heidegger, whose analysis covers only the central section of this conversation, understands knowledge, in this context, as a form of truth. So Socrates’ opening question to Theaetetus; “what is knowledge?,” in effect asks about the meaning of truth, i.e. aletheia.