In his biography of Polemon, head of the Academy from 313 to 269, Diogenes Laertius comments on Polemon's fondness for Sophocles after detailing Polemon's relationship with his predecessor, Xenocrates (4.19–20):
ἐῴκει δὴ ὁ Πολέμων κατὰ πάντα ἐζηλωκέναι τὸν Ξενοκράτην· καὶ ἐρασθῆναι αὐτοῦ φησιν Ἀρίστιππος ἐν τῷ τετάρτῳ Περὶ παλαιᾶς τρυφῆς. ἀεὶ γοῦν ἐμέμνητο ὁ Πολέμων αὐτοῦ, τήν τ' ἀκακίαν καὶ τὸν αὐχμὸν ἐνεδέδυτο τἀνδρὸς καὶ τὸ βάρος οἱονεὶ Δώριός τις οἰκονομία. ἦν δὲ καὶ φιλοσοφοκλῆς, καὶ μάλιστα ἐν ἐκείνοις ὅπου κατὰ τὸν κωμικὸν τὰ ποιήματα αὐτῷ
κύων τις ἐδόκει συμποιεῖν Μολοττικός,
καὶ ἔνθα ἦν κατὰ τὸν Φρύνιχον
οὐ γλύξις οὐδ' ὑπόχυτος, ἀλλὰ Πράμνιος.
ἔλεγεν οὖν τὸν μὲν Ὅμηρον ἐπικὸν εἶναι Σοφοκλέα, τὸν δὲ Σοφοκλέα Ὅμηρον τραγικόν.
It would seem that Polemon imitated Xenocrates in all respects. In the fourth book of On the Luxury of the Ancients, Aristippos says that he loved him. Certainly Polemon kept him in mind and, like him, wore that simple, dry dignity that is proper of the Dorian mode. He also loved Sophocles, particularly in those passages where it seemed as if, in the words of the comic poet, ‘a Molossian dog co-authored’ plays with him and where the poet was, in the words of Phrynichus, ‘neither bland nor doctored but Pramnian’. Thus he would call Homer the epic Sophocles and Sophocles the tragic Homer.
The main source of Diogenes Laertius'
Life of Polemon is Antigonus of Carystus, who was active in Athens and (apparently) Pergamon around the mid third century. In addition to being generally considered a reliable author, Antigonus is also chronologically close to Polemon's lifetime. He is also the source of Philodemus'
History of Philosophers, a work preserved by two important papyri from Herculaneum. Philodemus, too, mentions Polemon's admiration for Sophocles, although he gives a shorter version than Diogenes Laertius: λέγεται δὲ καὶ φιλοσοφοκλῆς γενέσθαι καὶ μά || λιστα τὸ ΠΑ[.]Α[……….] | τῆς φωνῆς καὶ παρα[….]
ἀποδέχεσθαι. In Dorandi's translation, Philodemus records that ‘si dice che [Polemone] fu ammiratore di Sofocle e soprattutto ne apprezzò l'audacia (del suono della lingua) e ciò che suonava duro’.