serve notice, with a possibly surprising trenchancy, that denial in the manner of concealment belongs to unconcealment as clearing. The proposition "the essence of truth is un-truth" is not, however, intended to state that truth is at bottom falsehood. Nor does it mean that truth is never itself but, viewed dialectically, is also its opposite.

Truth occurs precisely as itself in that the concealing denial, as refusal, provides the steady provenance of all clearing, and yet, as dissembling, metes out to all clearing the indefeasible severity of error. Concealing denial is intended to denote that opposition in the essence of truth which subsists between clearing and concealing. It is the opposition of the original strife. The essence of truth is, in itself, the primal strife in which that open center is won within which beings stand and from which they set themselves back into themselves.

This open region happens in the midst of beings. It exhibits an essential feature that we have already mentioned. To the open region there belongs a world and the earth. But the world is not simply the open region that corresponds to clearing, and the earth is not simply the closed region that corresponds to concealment. Rather, the world is the clearing of the paths of the essential guiding directions with which all decision complies. Every decision, however, bases itself on something not mastered, something concealed, confusing; else it would never be a decision. The earth is not simply the closed region but rather that which rises up as self-closing. World and earth are always intrinsically and essentially in conflict, belligerent by nature. Only as such do they enter into the strife of clearing and concealing.

Earth juts through the world and world grounds itself on the earth only so far as truth happens as the primal strife between clearing and concealing. But how does this happen? We answer: it happens in a few essential ways. One of these ways in which truth happens is the work-being of the work. Setting up a world and setting forth the earth, the work is the instigation of the strife in which the unconcealment of beings as a whole, or truth, is won.

Martin Heidegger (GA 5) The Origin of the Work of Art - Basic Writings (1993)