Athenaeus, Deipnosophists 6.233 b-d

“The comic poet Timokles says that tragedy is useful in our lives in many ways when he writes in the Women Celebrating the Dionysia (fr. 6):

Friend, listen, if anything I am about to say [seems right]
Man is a troubled creature by nature—
His life brings many pains with it.
Therefore, he invented these distractions from his thoughts:
For, once your mind forgets its own troubles,
Distracted by the spectacle of someone else’s suffering,
It departs both happy and educated.
If you will, examine first how all the tragedians
Benefit us. Since, one man who is penniless
Learns that Telephos is a bigger beggar than he is
And right away he bears his own poverty more easily.
Another man who is sick and a little crazy thinks
Of Alcmeon.* If someone has a bad eye, hey, Phineus’ sons
Were all blind! A child has died? Niobe can raise your spirits.
Some man is a cripple? He sees Philoktetes.
An old man has bad luck? He learns about Oeneus.
For when someone contemplates all the bad fortune
Worse than what he has suffered that has afflicted others
He groans less about his own problems.”

*Alcmeon killed his mother

Τιμοκλῆς ὁ κωμῳδιοποιὸς κατὰ πολλὰ χρησίμην εἶναι λέγων τῷ βίῳ τὴν τραγῳδίαν φησὶν ἐν Διονυσιαζούσαις (II 453 K)·

ὦτάν, ἄκουσον, ἤν τί σοι μέλλω** λέγειν.
ἅνθρωπός ἐστι ζῷον ἐπίπονον φύσει,
καὶ πολλὰ λυπήρ’ ὁ βίος ἐν ἑαυτῷ φέρει.
παραψυχὰς οὖν φροντίδων ἀνεύρετο
ταύτας· ὁ γὰρ νοῦς τῶν ἰδίων λήθην λαβὼν
πρὸς ἀλλοτρίῳ τε ψυχαγωγηθεὶς πάθει
μεθ’ ἡδονῆς ἀπῆλθε παιδευθεὶς ἅμα.
τοὺς γὰρ τραγῳδοὺς πρῶτον, εἰ βούλει, σκόπει
ὡς ὠφελοῦσι πάντας. ὁ μὲν ὢν γὰρ πένης
πτωχότερον αὑτοῦ καταμαθὼν τὸν Τήλεφον
γενόμενον ἤδη τὴν πενίαν ῥᾷον φέρει.
ὁ νοσῶν δὲ μανικῶς ᾿Αλκμέων’ ἐσκέψατο·
ὀφθαλμιᾷ τις, εἰσὶ Φινεῖδαι τυφλοί.
τέθνηκέ τῳ παῖς, ἡ Νιόβη κεκούφικε.
χωλός τίς ἐστιν, τὸν Φιλοκτήτην ὁρᾷ.
γέρων τις ἀτυχεῖ, κατέμαθεν τὸν Οἰνέα.
ἅπαντα γὰρ τὰ μείζον’ ἢ πέπονθέ τις
ἀτυχήματ’ ἄλλοις γεγονότ’ ἐννοούμενος
τὰς αὐτὸς αὑτοῦ συμφορὰς ῥᾷον φέρει.

**δοκῶ has been suggested as an alternative to μέλλω