οὐ γὰρ ἂν τό γε πραχθὲν ἀγένητον θείη → since he cannot make what was done as though it had not come to pass
ὁμοψύχως: Ἐπίρρ., μιᾷ ψυχῇ καὶ μιᾷ γνώμῃ, ὁμοθυμαδόν, μεταγεν.