ἔστι γὰρ ἡ κακία φθαρτικὴ ἀρχῆς (b19f.). "The κακία, the bad disposition, destroys the ἀρχή," i.e., does not allow the correct οὗ ἕνεκα to show itself. Here, in Dasein itself, is precisely where the risk to, and the resistance against, φρόνησις lies. Aristotle can then summarize the determination of φρόνησις as follows: ὥστ᾽ ἀνάγκη τὴν φρόνησιν ἕξιν εἶναι μετὰ λόγου ἀληθῆ περὶ τὰ ἀνθρώπινα ἀγαθὰ πρακτικήν (b20f.). Φρόνησις is a ἕξις of ἀληθεύειν, "a disposition of human Dasein such that in it I have at my disposal my own transparency." For its themes are the ἀνθρώπινα ἀγαθά. And it is a ἕξις of ἀληθεύειν which is πρακτική, "which lives in action. " That is why it is εὗ insofar as it comports itself ὁμολόγως to ὄρεξις, or to πρᾶξις,2 in such a way that the deliberation measures up to the "for the sake of which" of the acting. Φρόνησις itself is hence indeed an ἀληθεύειν, but it is not an autonomous one. It is an ἀληθεύειν in service to πρᾶξις. It is an ἀληθεύειν which makes an action transparent in itself. Insofar as the transparency of a πρᾶξις is constitutive for this πρᾶξις, φρόνησις is co-constitutive for the proper carrying out of the very action. Φρόνησις is an ἀληθεύειν; yet, as we said, it is not an autonomous one but rather one that serves to guide an action.
That is why Aristotle can think φρόνησις by delimiting it against the two other modes of ἀληθεύειν, τέχνη and ἐπιστήμη.
c) The delimitation of φρόνησις versus τέχνη and ἐπιστήμη. Φρόνησις as ἀρετή. Φρόνησις as "unforgettable" conscience. Σοφία as ἀρετή τέχνης.
The delimitation is carried out first in opposition to τέχνη. Now although φρόνησις, exactly like τέχνη, is directed to beings that can also be otherwise, yet τέχνη does not possess its ἔργον, while φρόνησις indeed does, and so one might presume that φρόνησις would be the ἀρετή of τέχνη. The ontological character of ἀρετή is τελείωσις; it constitutes the perfection of something, it brings something to completion, specifically something that has the potentiality for it, i.e., can also be without it. The question is thus whether φρόνησις can be the τελείωσις of τέχνη. ἀλλὰ μὴν τέχνης μὲν ἔστιν ἀρετή, φρονήσεως δ᾽ οὐκ ἔστιν (b21f.). "But in truth there is an ἀρετή for τέχνη, a possible τελείωσις; for φρόνησις there is none." For φρόνησις there is no τελείωσις. How are we to understand that for τέχνη an ἀρετή is possible? In the deliberation of know-how there are various degrees of development. Τέχνη can presume things and concede things. Trial and error are proper to it.
2. Cf. Nic. Eth. VI, 2, 1139a2ff.