conception and development if the problem of being has been governed by the fact that οὐσία is comprehended as substance, or better, as substantiality: substance as the proper beingness of a being. That this occurred, that the problem of being took the form of the problem of substance and led all further questioning in this direction, is no accident. The original impulses thereto can already be found in Plato and Aristotle. This cannot be demonstrated here, but we can at least provide some indications of how the rigidified problem of substance can be loosened up.
Substantia: id quod substat, that which stands undεr, ὑπόστασις. We have already encountered this ὑπο in the Aristotelian interpretation of movement. The first structural moment is the ύπομένον, i.e. that which is preserved through all changes of properties and thus through the transformation of the thing, that which is fixed so to speak, κεῖσθαι. Thus the expression ὑποκείμενον very often stands for ύπομένον. The innermost content of the concept of substance has the character of an enduring remaining, i.e. of constant presence.
d) Being and Actuality (Being-Present).
The Inner Structural Connection of οὐσία as παρουσία with ἐνέργεια
Summarizing what we have so far said concerning the Greek concept of being (οὐσία), three things emerge:
1. The interpretation of movement as a fundamental characteristic of beings is oriented to ἀπουσία and παρουσία, absence and presence.
2. The attempt to clarify the what being of beings, e.g. beautiful beings as such, is oriented to παρουσία.
3. The traditional conception of οὐσία as substance likewise involves the primordial meaning of οὐσία qua παρουσία.
After all this, the fundamental meaning of οὐσία in the sense of παρουσία still remains obscure.
Our thesis that being means constant presence can itself be demonstrated from the problematic, especially since we do not maintain that the Greeks explicitly recognized this understanding of being and made it into a thematic problem. Ware only saying that their questioning of beings proceeds within the horizon of this understanding of being.
But our thesis fails at a decisive point, namely if we focus on the concept of being predominant in ordinary employment of the word