Does the on ὅτι ἔστιν include only "actuality" or also possibility and necessity? Are the latter "modalities" modalities of actuality? If actuality itself is but one modality among others, then of what are these the modalities?
Does it suffice, preliminarily in the sense and horizon of the guiding question, to refer to distinctions in presence and absence, for example with respect to the present at hand and the ready to hand?
In any case, the immediate "thinking" of this distinction, as long as we continue to take such thinking as first and ultimate, does not exhibit anything that would determine the distinction as the proper horizon and the truth.
A merely formal (in the sense of taking the distinction as simply given and fallen from heaven) and dialectical consideration of the relation between essentia and existentia remains empty scholasticism and will be distinguished precisely by its remaining without a horizon and without a meditation on truth relative to the concepts of beingness in the broad sense. The expedient is then an attempt to explain "being" on the basis of the highest being as something produced and thought by this being.
Yet the historical fact remains: the development of the guiding question soon struck up against this distinction in beingness itself. Indeed very soon! At what point? When beings were interpreted as οὐσία—i.e., interpreted in the light of the ἰδέα. Why then and there? (Cf. The interplay, 110. The ἰδέα, Platonism, and idealism.) In a formal sense, it can be said that every "quiddity" has its modality and every modality is that of a quiddity. Thus both belong together. And hence the indication of a hidden, quite richer essence of beingness.
But essentia and existentia are not what is richer and are not the consequence of something simple. It is just the opposite: they are a certain impoverishment of an (in itself already richer) essence of beyng and of its truth (the temporality-spatiality of this truth as abyss).
The next step that must be taken in this confrontation is to manifest the thinking of οὐσία as a representing (νοεῖν) in its horizon and on its ground and to bring to light the character of οὐσία as constant presence. Today it is supposed that that character has always been known. That is correct and yet incorrect: correct, insofar as constancy and presence are implicitly meant and meant in advance, and yet incorrect insofar as these are not, precisely as such, brought to knowledge, grasped as "temporal" characteristics of a more originary time (of time-space), and—which is still more essential—questioned first from there.