therefore is truth? Truth is correspondence. Such correspondence exists because the assertion orients itself [sich richtet] according to that about which it speaks. Truth is correctness [richtigkeit]. (GA 34: 2)

But this correspondence or agreement, Heidegger argues, cannot be understood on a representational model of language. He argues instead that correspondence exists when our orientation to the world allows what is to show itself in a particular way, and thus it can be understood as a bringing out of concealment.

2. The truth (uncoveredness or discoveredness, Entdecktheit) of entities. An entity is true when it is uncovered, that is, made available for comportment.

Propositional truth (1) is grounded in the truth of entities, because a true assertion can only correspond or fail to correspond with the way things are if entities are available as the standard against which the assertion or proposition can be measured. Only because an entity is unconcealed, Heidegger argues, “can we make assertions about it and also check them. Only because the entity itself is true can propositions about the entity be true in a derived sense” (GA 27: 78).

The truth – that is, the uncovering or making manifest – of entities can be brought about through an assertion or a theoretical apprehension, but it normally occurs in our practical involvements with things in the world. “Ontic manifesting ... happens in accordance with an attuned [stimmungsmäßigen] and instinctive finding oneself in the midst of entities, and in accordance with the striving and moving comportment to entities that is grounded along with it” (GA 9:131).

3. The truth of being. There is an unconcealment (Unverborgenheit) of being when an understanding of the being or essence of everything that is shapes all the possibilities for comportment in the world.

Ontic truth (2) is grounded in the truth of being. Heidegger argued that entities are constituted as the entities they are by the relationships they bear to things, people, activities, and so on. Nothing is what it is without these relationships. There are then two sides to being as the constitutive ground of an entity. First, there must be more or less enduring relationships for the entity to inhabit. Second, it must be possible to distinguish between those relationships that are essential to the being of the entity, and those that are not. The unconcealment of being involves both those two sides:

(a) The disclosure (Erschlossenheit) of Dasein and of the world. The idea is that entities can only be available for comportment on the basis of a prior disclosure of the world as the meaningful relational structure within which entities can show up as what they are. In addition, since entities are uncovered in terms of their availability for comportment,

Heidegger and Unconcealment by Mark A. Wrathall