Heidegger, Martin, The The Essence of the Truth: On Plato's Parable of the Cave, New York: Continuum, 2002.

Excerpt:

We wish to consider the essence of truth.

‘Truth’: what is that? The answer to the question ‘what is that?’ brings us to the ‘essence’ of a thing. ‘Table’: What is that? ‘Mountain, ‘ocean’, ‘plant’; in each case the question ‘what is that?’ asks about the ‘essence’ of these things. We ask – and yet we already know them! Indeed, must we not know them, in order afterward to ask, and even to give an answer, about what they are?

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