In other words, in our process of destruction we find ourselves faced with the task of Interpreting the basis of the ancient ontology in the light of the problematic of Temporality. When this is done, it will be manifest that the ancient way of interpreting the Being of entities is oriented towards the 'world' or 'Nature' in the widest sense, and that it is indeed in terms of 'time' that its understanding of Being is obtained. The outward evidence for this (though of course it is merely outward evidence) is the treatment of the meaning of Being as παρουσία or οὐσία, which signifies, in ontologico-Temporal terms, 'presence' ["Anwesenheit"].1 Entities are grasped in their Being as 'presence'; this means that they are understood with regard to a definite mode of time—the 'Present'2
The problematic of Greek ontology, like that of any other, must take its clues from Dasein itself. In both ordinary and philosophical usage, Dasein, man's Being, is 'defined' as the ζῷον λόγον ἔχον—as that living thing whose Being is essentially determined by the potentiality for discourse.3 λέγειν is the clue for arriving at those structures of Being which belong to the entities we encounter in addressing ourselves to anything or speaking about it [im Ansprechen und Besprechen]. (Cf. Section 7 B.) This is why the ancient ontology as developed by Plato turns into 'dialectic'. As the ontological clue gets progressively worked out-namely, in the 'hermeneutic' of the λόγος—it becomes increasingly possible to grasp the problem of Being in a more radical fashion. The 'dialectic', which has been a genuine philosophical embarrassment, becomes superfluous. That is why Aristotle 'no longer has any understanding' of it, for he has put it on a more radical footing and raised it to a new level [aufhob].
1 The noun οὐσία is derived from one of the stems used in conjugating the irregular verb εἶναι, ('to be'); in the Aristotelian tradition it is usually translated as 'substance', though translators of Plato are more likely to write 'essence', 'existence', or 'being'. Heidegger suggests that οὐσία is to be thought of as synonymous with the derivative noun παρουσία ('being-at', 'presence'). As he points out, παρουσία has a close etymological correspondence with the German 'Anwesenheit', which is similarly derived from the stem of a verb meaning 'to be' (Cf. O.H.G. 'wesan') and a prefix of the place or time at which ('an-'). We shall in general translate 'Anwesenheit' as 'presence', and the participle 'anwesend' as some form of the expression 'have presence'.
2 'die "Gegenwart" '. While this noun may, like παρουσία or 'Anwesenheit', mean the presence of someone at some place or on some occasion, it more often means the present, as distinguished from the past and the future. In its etymological root-structure, however, it means a waiting-towards. While Heidegger seems to think of all these meanings as somehow fused, we shall generally translate this noun as 'the Present', reserving 'in the present' for the corresponding adjective 'gegenwärtig'.
3 The phrase ζῷον λόγον ἔχον is traditionally translated as 'rational animal', on the assumption that λόγος refers to the faculty of reason. Heidegger, however, points out that λόγος is derived from the same root as the verb λέγειν ('to talk', 'to hold discourse'); he identifies this in turn with νοεῖν ('to cognize', 'to be aware of', 'to know'), and calls attention to the fact that the same stem is found in the adjective διαλεκτικός ('dialectical'). (See also H. 165 below.) He thus interprets λόγος as 'Rede', which we shall usually translate as 'discourse' or 'talk', depending on the context. See Section 7 a below (H. 32 ff.) and Sections 34 and 35, where 'Rede' will be defined and distinguished both from 'Sprache' ('language') and from 'Gerede' ('idle talk') (H. 160 ff.).