their uncovering requires the prior disclosure of Dasein as an acting and understanding being. In Being and Time, Heidegger expressed this idea as follows: “the uncoveredness of entities within-the-world is grounded in the world’s disclosedness. But disclosedness is that basic character of Dasein according to which it is its ‘there.’ Disclosedness is constituted by disposedness (Befindlichkeit), understanding, and discourse, and pertains equiprimordially to the world, to being-in, and to the self” (GA 2: H. 221).
(b) The truth of essence. Entities can be manifest in their truth, that is, as what they really are, only if they are unconcealed in their essence – which means, they (come to) have an essence. Heidegger’s catchphrase for this is: “The essence of truth is the truth of essence” (GA 9: 201; see also GA 45: 95; GA 65: 288; GA 5: 37). This means that the unconcealment of beings requires first an unconcealment of the most fundamental, essential aspect of entities that makes them what they are. This works not by being thought about, but by disposing us to encounter entities in a particular way, as having a particular essence. We encounter entities, in other words, on the basis of “an original view (form) that is not specifically grasped, yet functions precisely as a paradigmatic form for all manifest beings” (GA 9: 158/123).
What both (3a) and (3b) have in common is the insight that entities can only be manifest on the basis of a prelinguistic understanding of and affective disposedness to what makes something the being that it is.
Heidegger eventually comes to believe that the truth of being depends on:
4. Truth as the clearing (Lichtung). There is a clearing within which an understanding of being or essence can prevail while incompatible possibilities of being are concealed or held back.
This is the most fundamental form of unconcealment. Unconcealment, when understood as the clearing, does not name a thing, or a property or characteristic of things, or a kind of action we perform on things, or even the being of things. It names, instead, a domain or structure that allows there to be things with properties and characteristics, or modes of being. This is not a spatial domain or physical entity, or any sort of entity at all. It is something like a space of possibilities.
Planks 1–3 give us possibilities for different experiences of entities and different actions with entities, for different goals to be pursued, or forms of life to be lived. These possibilities are the possibilities opened up by the understanding of being and essences. But what is the space that allows those possibilities to be actual possibilities – that is, to be the possibilities that actually shape a given historical existence? This is to ask “what, given that there has been a progression of different truths of being in history, allows any particular truth of being to prevail?”