1. Pseudoplut. Vit. X οr. 839 f.: καταλέλοιπε δὲ (Isaeus)… καὶ ἰδίας τέχνας, πρῶτος δὲ καὶ σχηματίζειν ἤρξατο καὶ τρέπειν ἐπὶ τὸ πολιτικὸν τὴν διάνοιαν (sic).
Ibid. supra: καθηγήσατο δὲ Δημοσθένους, ἀποστὰς τῆς σχολῆς. Cf. Dionysii Hal. ad Ammaeum p. 259, 5 sq., ubi inter παραγγελμάτων τεχνικῶν συγγραφεῖς Isaeus nominatur. Ipsas vero orationes intellegit Pytheas, Demostheni obiciens ὅτι τὸν Ἰσαῖον ὅλον καὶ τὰς τῶν λόγων ἐκείνου τέχνας σεσίτισται (fr. 3 S. apud Dionysium Hal. I p. 96, 22 Us.-R.).
Vide etiam Isaei 4, 12: ἐν μόναις δὲ ταῖς τῶν κλήρων εἰσαγωγαῖς δοκεῖ μοι προσήκειν τεκμηρίοις μᾶλλον ἢ μάρτυσιν πιστεύειν. περὶ μὲν γὰρ τῶν ἄλλων συμβολαίων οὐ πάνυ χαλεπὸν τοὺς τὰ ψευδῆ μαρτυροῦντας ἐλέγχειν, ζῶντος γὰρ καὶ παρόντος τοῦ πράξαντος καταμαρτυροῦσι. περὶ δὲ διαθηκῶν πῶς ἄν τις γνοίη τοὺς μὴ τἀληθῆ λέγοντας – εἰ μὴ πάνυ μεγάλα τὰ διαφέροντα εἴη –, αὐτοῦ μὲν καθʼ οὗ μαρτυροῦσι τεθνεῶτος, τῶν δὲ συγγενῶν μηδὲν τῶν πεπραγμένων εἰδότων, τοῦ δὲ ἐλέγχου μηδαμῶς ἀκριβοῦς γιγνομένου;
Isaei 7, 1: ᾤμην μέν, ὦ ἄνδρες, προσήκειν οὐ τὰς τοιαύτας ἀμφισβητεῖσθαι ποιήσεις, εἴ τις αὐτὸς ζῶν καὶ εὖ φρονῶν ἐποιήσατο καὶ ἐπὶ τὰ ἱερὰ ἀγαγὼν εἰς τοὺς συγγενεῖς ἀπέδειξε καὶ εἰς τὰ κοινὰ γραμματεῖα ἐνέγραψεν, ἅπανθʼ ὅσα πρoσῆκεν αὐτὸς ποιήσας, ἀλλʼ εἴ τις τελευτήσειν μέλλων διέθετο, εἴ τι πάθοι, τὴν οὐσίαν ἑτέρῳ, καὶ ταῦτʼ ἐν γράμμασι κατέθετο παρά τισι σημηνάμενος. ἐκεῖνον μὲν γὰρ τὸν τρόπον ποιησάμενος φανερὰς κατέστησε τὰς αὑτοῦ βουλήσεις, ὅλον τὸ πρᾶγμα ἐπικυρώσας, δόντων αὐτῷ τῶν νόμων. ὁ δʼ ἐν διαθήκαις σημηνάμενος ἀδήλους ἐποίησε.
Isaei 4, 22: ἔλεγχοι (sc. εἰσὶ) περὶ ἀφανῶν.
Isaei 8, 28: πόθεν χρὴ πιστεύεσθαι τὰ εἰρημένα; οὐκ ἐκ τῶν μαρτυριῶν; οἶμαί γε. πόθεν δὲ τοὺς μάρτυρας; οὐκ ἐκ τῶν βασάνων; εἰκός γε. πόθεν δʼ ἀπιστεῖν τοῖς τούτων λόγοις; οὐκ ἐκ τοῦ φεύγειν τοὺς ἐλέγχους; ἀνάγκη μεγάλη. Haec perpaucis verbis mutatis repetuntur in fragmento Isaei apud Dionysium Hal. p. 108 Us.-R. servatο (fr. X 2 S. fr. II Bn.) Cf. Caecili Calactini fr. 164 Ofenl.
Isaei 4, 18: εἰ μὲν οἳ κατὰ τὰς διαθήκας ἀμφισβητοῦντες ὁμολογουμένως Νικοστράτῳ ἐπιτήδειοι ὄντες ἐτύγχανον, τὸ μὲν ἀκριβὲς οὐδʼ ἂν οὕτως, ὅμως μέντοι μᾶλλον εἰκὸς ἦν ἀληθεῖς εἶναι δόξειν τὰς διαθήκας.
Isaei 4, 22: πολὺ τὸ διαφέρον κατὰ γένος ἢ κατὰ δόσιν ἀμφισβητεῖν.
1. Pseudo-Plutarch, Lives of the Ten Orators: [Isaeus] too has left behind his own treatises. He was the first to use figures and to turn people’s attention to politics.
Ibid. above: ‘He was the teacher of Demosthenes after abandoning the school.’ Cf. Dionysius Hal. To Ammaeus p. 259, 5 f., where Isaeus is named among ‘the writers of teaching treatises.’ Pytheas, however, understands the speeches themselves, objecting to Demosthenes ‘that he has eaten up the entire Isaeus and his rhetorical devices (frag. 3 S. in Dionysius Hal. I p. 96, 22 Us.-R.).
See also Isaeus 4.12: ‘Only in lawsuits about inheritance does it seem appropriate to me to trust evidence more than witnesses. For as regards all other interactions, it is not at all difficult to refute those who lie, as they testify while the person that did something is alive and present. In the case of testaments, on the other hand, how can we recognize when someone is lying (unless the discrepancies in the evidence are very large), since the person they are testifying about is dead, none of the relatives know anything about what happened, and the proof cannot in any way be brought with any certainty?
Isaeus 7.1: ‘I thought, gentlemen, that one ought to dispute not those adoptions that somebody who is still alive and with a clear head has made himself, where he has led his adoptive son to the altars and revealed him to the family, and has written him into the public registers, doing himself all that he had to do; but rather those ones where someone who was about to die has bequeathed his property to another in the case of his death and he has put this decision in writing, sealed it up and deposited it with someone. For if he has adopted in the former way, he has made clear what he wants, giving legitimacy to the entire affair in the manner granted him by the law; the one who uses sealed testaments, on the other hand, has made it unclear.’
Isaeus 4.22: ‘Arguments are about unseen things.’
Isaeus 8.28: ‘Based on what must one trust what has been said? The testimonies? I think so. And based on what must one trust the witnesses? Torture? Likely. Based on what, then, must one distrust these people’s words? Not based on their eschewing such tests? Yes we must!’ The same statement, except for a few different words, is repeated in the fragment of Iseaus conserved in Dionysius Hal. p. 108 Us.-R. (frag. X 2 S.; frag. II Bn.). Cf. Caecilius Calactinus frag. 164 Ofenl.
Isaeus 4.18: ‘If those who base their argument on the testament were admittedly friends of Nicostratus, we would not attain full certainty in this way either, but the testament would nonetheless have a greater chance of being seen as authentic.’
Isaeus 4.22: ‘There is a big difference whether you base your case on descendance or on a gift.’