Through τέχνη, one discovers whether something works or not. The more τέχνη risks failure, the more secure it will be in its procedure. It is precisely through failure that certitude is formed. It is precisely the one who is not ingrained in a definite technique, a set routine, but again and again starts anew and cuts through rigid procedure, who acquires the correct possibility of know-how, has at his disposal the proper kind of the ἀληθεύειν that corresponds to τέχνη, and acquires more and more of that kind of uncovering. καὶ ἐν μὲν τέχνῃ ὁ ἑκὼν ἁμαρτάνων αἱρετώτερος (b22f.). The possibility of failure is an advantage belonging to τέχνη itself. It is precisely on the basis of this possibility that τέχνη is τελειωτέρα. This possibility of failure is constitutive for the development of τέχνη. But in the case of φρόνησις, on the contrary, where it is a matter of a deliberation whose theme is the proper Being of Dasein, every mistake is a personal shortcoming. This shortcoming with regard to oneself is not a higher possibility, not the τελείωσις of φρόνησις, but precisely its corruption. Other than failure, the only possibility open to φρόνησις is to genuinely hit the mark. Φρόνησις is not oriented toward trial and error; in moral action I cannot experiment with myself. The deliberation of φρόνησις is ruled by the either-or. φρόνησις is by its very sense στοχαστική; it has a permanent orientation, it pursues the goal, and specifically the μεσότης. With φρόνησις, unlike τέχνη, there is no more or less, no "this as well as that," but only the seriousness of the definite decision, success or failure, either-or. Insofar as φρόνησις is στοχαστική, it is impossible for it to be more complete. Thus it has no ἀρετή but is in itself ἀρετή. In this way, the very mode of the carrying out of ἀληθεύειν is different in the case of φρόνησις from the one of τέχνη, although both, in terms of their objects, are concerned with beings which can also be otherwise. Thereby we have gained a delimitation. Φρόνιμος cannot be the ἀρετή of τέχνη-because of its very mode of carrying out ἀληθεύειν, quite apart from the fact that the object of τέχνη is a πρακτόν, whereas the object of φρόνησις is a πρακτόν. Thus it is clear that φρόνησις is an ἀρετή but is not a τέχνη: δῆλον οὖν ὅτι ἀρετή τίς ἐστιν καὶ οὐ τέχνη (b24f.). And because φρόνησις is directed at once to the ἀρχή and the τέλος and preserves both, it is the βελτίστη ἕξις of the ἀληθεύειν that corresponds to those beings which can also be otherwise.
How then does φρόνησις relate to ἐπιστήμη? The λόγον ἔχον is divided into two basic possibilities: the λογιστικόν and the ἐπιστημονικόν. Since φρόνησις is not the ἀρετή of τέχνη, the question arises whether it can be the ἀρετή for ἐπιστήμη, for the ἐπιστημονικόν. Now it does indeed appear that φρόνησις is the ἀρετή of ἐπιστήμη, admittedly of an early stage of ἐπιστήμη. Within knowledge then is in fact a mode of disclosure which, precisely as in the case of φρόνησις, relates to beings which can also be otherwise: δόξα. ἥ τε γὰρ δόξα περὶ τὸ ἐνδεχόμενον ἄλλως ἔχειν καὶ ἡ φρόνησις. (b27f.).