The distinction between the Being of existing Dasein and the being of beings unlike Dasein (for example, reality) may seem to be illuminating, but it is only the point of departure for the ontological problematic; it is not something with which philosophy can rest and be satisfied.

MARTIN HEIDEGGER, BEING AND TIME (1927)

What now is stands in the shadow of the destiny of oblivion of Being that already preceded it. The difference between being and the Being, however, can be experienced as something forgotten only if it is unveiled along with the presencing of what is present; only if it has left a trace, which remains preserved in the language, to which Being comes. Thinking along these lines, we may surmise that the difference has shown up more in the earlier than in the later word of Being—though never having been named as such. Illumination of the difference, therefore, cannot mean that the difference appears as the difference. On the contrary, it may be that the relation to what is present announces itself in the presencing as such, in such a way, indeed, that presencing comes to speak as this relation.

MARTIN HEIDEGGER, OFF THE BEATEN TRACK (1950)

Our thinking, or better expressed, our reckoning and accounting according to the principle of noncontradiction, can hardly wait to offer the observation that a history which is, but in which there is nothing to Being itself, presents us with an absolute absurdity. But perhaps Being itself does not trouble itself about the contradictions of our thought. If Being itself had to be what it is by grace of a lack of contradiction in human thought, then it would be denied in its own proper essence. Absurdity is impotent against Being itself, and therefore also against what happens to it in its destiny—that within metaphysics there is nothing to Being as such.

MARTIN HEIDEGGER, NIETZSCHE (1961)