Sir Richard C. Jebb, Commentary on Sophocles: Philoctetes

παλαιὸν=“παλαιόν” (“ἐστιν”) ἐξ ὅτου, a parenthetic clause equiv. to a simple adverb (“πάλαι”) going with “δέδοικα”. Cp. Isocr. or. 5 § 47 “οὖτοι γὰρ ἄρχοντες τῶν Ἑλλήνων οὐ πολὺς χρόνος” (sc. “ἐστὶν”) “ἐξ οὖ καὶ κατὰ γῆν καὶ κατὰ θάλατταν εἰς τοσαύτην μεταβολὴν ἦλθον.” Ai. 600“ἐγὼ δ᾽ ὁ τλάμων παλαιὸς ἀφ᾽ οὗ χρόνος” | ...“εὐνῶμαι”.—In L “παλαιὰν” is manifestly a mere blunder for “παλαιὸν”. Those who read παλαἴ ἂν explain it in one of two ways. (1) “εἴη” is to be supplied with it, —“βεβήκῃ”, or “βέβηκε”, being read in 494. Such an ellipse of “εἴη” is impossible. (2) The “ἂν” is to go with “βεβήκοι” in 494. Cp. Tr. 630“δέδοικα γὰρ” | “μὴ πρῲ λέγοις ἄν”: Thuc. 2. 93“προσδοκία οὐδεμία” (“ἦν”) “μὴ ἄν ποτε οἱ πολέμιοι...ἐπιπλεύσειαν”. But in this constr. the “ἄν” which belongs to the optative verb could not precede the “μή”. In Eur. Med. 941“οὐκ οἶδ᾽ ἂν εἰ πείσαιμι”, the place of “ἄν” has a special excuse, viz., the analogy of sentences with the inf. (such as “οὐκ ἂν οἶμαι πεῖσαι”).