The Essence of Truth: On Plato’s Cave Allegory and Theaetetus

Most of Heidegger’s readings of early and classical Greek texts are unconventional by traditional philosophical and philological standards. The present reading of Plato is no exception. Heidegger suggests that the “essence of truth is what first allows the essence of man to be grasped” and “the man whose liberation is depicted in the allegory is set out into the truth.” But since such “setting out” is the very “mode of his existence, the fundamental occurrence of his Dasein,” the allegory is not chiefly about the essence of truth but, as already noted, rather about “an occurrence happening ‘in man’, that is, in his history”. The real novelty of Heidegger’s reading, however, is his conclusion that the “decisive result of the interpretation of the cave allegory... [is] the insight that the question concerning the essence of truth as unhiddenness must be transformed into the question concerning untruth”, that is, “that untruth belongs to the essence of truth”. For this reason Heidegger’s course takes a turn to a passage in the Theaetetus, which he dramatically characterizes as “that stretch of the road of the question concerning untruth which, for the first and last time in the history of philosophy, Plato actually trod”. While the dialogue is generally taken to be about knowledge, for Heidegger it is about untruth.