Present and presence means: what is with us. And that means: to endure in the encounter.
We may recall here how Kant, at the peak of modern European thinking, in his Critique of Pure Reason defines the individual being (ὄν,) that is demonstrable in its being. Kant defines being as the object of experience. The object is characterized by enduring in the encounter. The object is characterized by presence, and thus by being here. If the individual being, τὸ ἐόν, were not manifest even as something that is here, beings could never appear as objects. If εἶναι (Being) did not prevail as a being present, the question of the presence of the object, that is, of the object's objectivity, could not even be asked. If the ἐόν ἔμμεναι in the sense of the being here of what is present, did not prevail, Kant's thinking would have no place in which to make even a single statement of his Critique of Pure Reason. Nor is this all.
If the Being of beings, in the sense of the being here of what is present, did not already prevail, beings could not have appeared as objects, as what is objective in objects and only by such objectivity do they become available to the ideas and propositions in the positing and disposing of nature by which constantly take inventory of the energies can wrest from nature. This disposition of nature according to its energy supply arises from the hidden essence of modern technology.
If εἶναι, Being of beings, did not prevail—in the sense of the being here and thus objectivity of the inventory of objects—not only would the airplane engines fail to function, they would not exist. If the Being of beings, as the being here of what is present, were not manifest, the electric energy of the atom could never have its appearance, could never have put to work in its way—work in every respect determined by technology. It may thus be of some importance whether hear what the decisive rubric of Western-European thinking, ἐόν, says--or whether we fail to hear it.