ἄλογον δὴ τὸ μήτε μάχης ἄρξασθαι μήτε τοὺς φίλους φυλάξαι, ἐὰν ὑπό γε τῶν βαρβάρων ἀδικῆσθε → It is irrational neither to begin battle nor to guard the friends, if you are ever wronged by the foreigners
unmindful of: P. and V. ἀμνήμων (gen.).
forgetful: Ar. and P. ἐπιλήσμων.
be unmindful (of), v.: P. and V. ἀμνημονεῖν (gen. or absol.); see forget.