ἐπεὶ ἐμέ γε ἔλαθεν
is this elathen impersonal?
or rather the subject is ‘the fact that the poet should say what ought to be said’ understood from the context.
cf 237c: τοὺς δὲ πολλοὺς λέληθεν ὅτι οὐκ ἴσασι τὴν οὐσίαν ἑκάστου
i think here it is impersonal
Well, we don’t actually need to decide: “I didn’t notice,” he says—what or whom he didn’t notice is left unspecified. But surely the subject is the person they’re talking about here—we have εἰρηκότος τοῦ ποιητοῦ just above, and μοι ἔδοξεν etc. (personal!) just below. So “he” must be the subject.
237c is quite different. The subject there is the ὅτι clause.