Note 643 — Chapter LIII · EIGHTH YEAR OF THE WAR.
Reading edition
Thucydidês, in describing the state of mind of the Bœotians, does not seem to imply that they thought this a good and valid ground, upon which they could directly take their stand; but merely that they considered it a fair diplomatic way of meeting the alternative raised by the Athenian herald; for εὐπρεπὲς means nothing more than this.
Οὐδ᾽ αὖ ἐσπένδοντο δῆθεν ὑπὲρ τῆς ἐκείνων (Ἀθηναίων)· τὸ δὲ ἐκ τῆς ἑαυτῶν (Βοιωτῶν) εὐπρεπὲς εἶναι ἀποκρίνασθαι, ἀπιόντας καὶ ἀπολαβεῖν ἃ ἀπαιτοῦσιν.
The adverb δῆθεν also marks the reference to the special question, as laid out by the Athenian herald.