Thus far, we have suppressed a further character of the world as encountered, the ἀγαθóν, although Aristotle ultimately characterizes the συμφέρον as ἀγαθóν. We are now prepared to understand what the ἀγαθóν means. Aristotle gives a description thereof at the aforementioned place in Book 1, Chapter 6 of the Rhetoric, precisely in connection with the definition of the συμφέρον.
Αγαθóν is:
1. αὐτὸ ἑαυτοῦ ἕνεκα αἱρετóν, that which is “graspable in itself and for its own sake”—hence the determination of ἀγαθóν as οὗ ἕνεκα, “for-the-sake-of-which,” “for-the-sake-thereof.”
2. καὶ οὗ ἕνεκα ἄλλο. The reference runs, in the reverse order from before, from τέλος to συμφέρον. To see the fundamental context, one must note that the ἀγαθóν has primarily the character of an end only because it can be a for-the-sake-of-which, a for-the-sake-of-another.
3. Further, the ἀγαθóν is determined as οὗ ἐφίεται πάντα, “that toward which everything maintains itself, that toward which it is under way”; specifically,
4. οὗ παρóντος, and this “insofar as it is present,” εὖ διάκειται. If the ἀγαθóν is there as such, if concern is brought to its end, then the one who is concerned εὖ διάκειται is in a disposition that is characterized as εὖ. Εὖ is a definite how of finding-oneself-disposed, which is cultivated insofar as it is settled for the one concerned. The εὖ is dependent upon the manner and mode of concern for the end.
These various determinations of ἀγαθóν all run together in that the ἀγαθóν is primarily end, τέλος, or more precisely, πέρας. We have already seen πέρας as a fundamental determination of being. (Heidegger, GA18:57-58)
In Chapter 4 (EN6), Aristotle comes to the conclusion that there cannot be a good in itself. Ἀγαθóν is in itself always πέρας of a πρᾶξις, and this πρᾶξις is, however, here and now, going toward what is here and now. Πρᾶξις is always περὶ τὰ ἔσχατα καὶ τὰ καθ᾿ ἕκαστα, (EN6 12, 1143 a 32 sq) “going toward the outermost, toward the ultimate here and now,” καὶ τὰ καθ᾿ ἕκαστα, toward “the particular as such in its definiteness.” For this reason, the idea of an ἀγαθóν καθóλου (EN1 4, 1096 a 11) is senseless, as it misjudges the being-character of the ἀγαθóν itself. (Heidegger, GA18:79)