e) The Question of the Being-True of Proper Beings as the Highest and
Deepest Question of Aristotle's Interpretation of Being.
Θ 10 as Keystone to Book Θ and to Aristotelian Metaphysics in General
Once this thematic content of Θ 10 has been brought to light through an interpretation informed by the Greek understanding of being and truth, κυριώτατον as the character of ἀληθὲς ὄν will no longer be found disturbing. On the contrary, one would have to find it surprising if κυριώτατον did not appear where it does. At the same time it should be clear that the way Aristotle develops the problem of being-true has nothing to do with logic or epistemology. The question concerning being-true unfolds as the fundamental problem of the proper being οf beings themselves and as such stands in the closest possible relation to what was treated in the foregoing chapters of Book Θ. Let me provide yet another indication of the unambiguously positive connection between Θ 10 and Θ , in order to counter the possible view that, although Θ 10 does indeed relate to Θ it does not actually belong to this book. The topic of Book Θ is δύναμις and ἐνέργεια, i.e. possibility and actuality as fundamental modes of being. It is shown that proper being is ἐνέργεια. Proper beings are those which exclude every possible change, every possibility of becoming-other. We are in the habit of saying that for something to be actual, it' must first be possible. Thus possibility is primary and prior, before actuality. But Aristotle maintains the contrary position: πρότερον ἐνέργεια δυνάμεώς ἐστιν.54 Actuality is prior and primary with respect to possibility. To be sure, this can only be maintained on the basis of the specifically Greek approach to the problem of being, including the fundamental conception of truth as deconcealment. This is not to be entered into now. We do say, however, that Θ 10 discusses a fundamental aspect of the whole thematic question, i.e. the ever more comprehensive exclusion of the possibility of untruth from truth. In Θ 10 there is concentrated the most radical conception of the basic problem of Θ. In a word: Θ 10 is not a foreign appendix, but rather the keystone of Book Θ, which itself is the centre of the entire Metaphysics.
So from the textual question we have gained some insight into the fundamental Greek meaning of being-true as constant presence. As indicated at the outset, this conception of truth is not just Aristotelian, but simply Greek. We have become familiar with the leading question
54 Metaphysics Θ 8, 1049 b 5.