E.C. Marchant, Commentary on Thucydides: Book 3

θεαταὶ μὲν . . ἔργων—‘spectators of words and hearers of deeds’ is an artificial way of saying: you are content to take the facts from what the orators say, and look on at the debates, thus inverting the natural order of things at an ἀγών, in which one would watch the athletes' deeds and listen to the literary men's words: so badly do you, who are at once the directors and the people attending, manage the ἀγῶνες. (The explanations usually given of this passage do not seem to me to give an intelligible meaning to the whole: (a) κακῶς ἀγωνοθετεῖν does not mean ‘to be wrong in instituting a contest,’ but ‘to do so in the wrong way’; cf. the second and third failings—ἀπατᾶσθαι ἄριστοι and ζητοῦντες ἄλλο τε κτλ.: all indicative of a topsy-turvy mind and (b) only with the latter meaning—which is a natural one—does οἵτινες κτλ. given an intelligible reason.)

ὡς δυνατὰ γίγνεσθαι—‘as practicable’: sc. ὄντα, cf. VI. 40 τοὺς λόγους ὡς ἔργα δυναμένους κρινεῖ.

τὰ δὲ π. ἤδη—sc. σκοποῦντες.

οὐ τὸ . . ἀκουσθέν ‘not taking what has been done as more trustworthy through having seen it, than what you have heard (about it).’ (It has been objected to ὄψει that we need ἀκροάσει or ἀκοῇ to contrast with it; but the whole clause corresponds to ὡς δυνατὰ γίγνεσθαι, and = ὡς τὸ ἀκουσθὲν πιστότερον ὂν ἢ τὸ ὀφθέν; τὸ ἀκουσθέν itself contains the contrast to ὄψει: instead of saying τὸ ὀφθέν, Thuc. says τὸ δρασθέν in order to introduce again the contrast between ἔργα and λόγοι —δρασθέν and ἀκουσθέν.)

ἐπιτιμησάντων—the readiness of speakers to criticize adversely the action of public men, if opponents, is often insisted on; but it is odd that Cleon, who was ever ready to censure, should talk so.