Oh child, words well spoken might be false,
and with the beauty of words, might conquer truth;
yet this is not the surest test, that is character
and right; he who conquers with his fluency,
he is clever, but I hold facts mightier than words, always.

[ὦ παῖ, γένοιντ᾽ἂν εὖ λελεγµένοι λόγοι
ψευδεῖς, ἐπῶν δὲ κάλλεσιν νικῷεν ἂν
τἀληθές· ἀλλ᾽οὐ τοῦτο τἀκριβέστατον,
ἀλλ᾽ἡ φύσις καὶ τοὐρθόν· ὃς δ᾽εὐγλωσσίᾳ
νικᾷ, σοφὸς µέν, ἀλλ᾽ἐγὼ τὰ πράγµατα
κρείσσω νοµίζω τῶν λόγων ἀεί ποτε.]

Euripides (485?-406? BC) Greek tragic dramatist

Antiope [Αντιοπη], frag. 206 (Kannicht) [Antiope/ΑΝΤΙΟΠΗ?] (c. 410 BC) [tr. Will (2015)]
    (Source)

(Source (Greek)). TGF frag. 205.