V. The Grounding [335-336]

5. What was said in point 4 is ineluctable, because point 2 holds good, i.e., because ἀλήθεια is always understood in a genuinely Greek way solely on the basis of beings and their constant presence; at best, it is understood as the "between."
Yet, as history shows, that is not sufficient. Unconcealedness must be fathomed and grounded as the openness of beings as a whole, and openness must be fathomed and grounded as the openness of self-concealing (being), and the latter as Da-sein.

212. Truth as certainty

Insofar as ratio is here not at first opposed to fides but, as equal to fides, wants to stand on its own, what remains to ratio (representation) is only the relatedness to itself for the sake of possessing itself in its own way. This representation of the "I represent" is certainty, the knowledge that is known to itself as such.

Thereby, however, ratio itself degrades itself below itself, descends below its own "niveau," which in the beginning consisted indeed in the immediate perception of beingness as a whole.

Reason [Vernunft], degraded in this way, is brought to the mere semblance of a mastery (on the basis of the self-demeaning). This semblance of mastery must be shattered some day, and the present centuries are carrying out this shattering, though it is necessarily accompanied by the continuous increase of "rationality" as "principle" of machination.

As soon as reason is degraded below itself, however, it becomes more graspable to itself, so much so that it now completely draws from this result the paradigm for understandability and insightfulness. Such insightfulness then becomes the measure for what is valid and can be valid, i.e., now, for what is allowed to be and may be said to be.

Being itself now becomes all the more graspable, customary, and free of any strangeness.

What is established in Plato, especially the priority of beingness as interpreted on the basis of τέχνη, is now so sharply intensified and elevated into exclusivity that there is created the basic condition for a human era in which "technology" (the priority of what is machinational, of regulations and procedures over that which is affected by these and taken up into them) necessarily assumes the mastery. Beyng, and truth as certainty, now become self-evident without limit. The fact that beyng is forgettable thereby becomes an axiom, and the forgottenness of being, which sets in at the beginning, expands and overlays all human comportment.

Contributions to Philosophy (of the Event) (GA 65) by Martin Heidegger