Thucydides 4.108.4 (tr. Benjamin Jowett):
They judged rather by their own illusive wishes than by the safe rule of prudence. For such is the manner of men; what they like is always seen by them in the light of unreflecting hope, what they dislike they peremptorily set aside by an arbitrary conclusion.
τὸ δὲ πλέον βουλήσει κρίνοντες ἀσαφεῖ ἢ προνοίᾳ ἀσφαλεῖ, εἰωθότες οἱ ἄνθρωποι οὗ μὲν ἐπιθυμοῦσιν ἐλπίδι ἀπερισκέπτῳ διδόναι, ὃ δὲ μὴ προσίενται λογισμῷ αὐτοκράτορι διωθεῖσθαι.
Caesar, Gallic War
3.18 (tr. T. Rice Holmes):
In most cases men willingly believe what they wish.
Fere libenter homines id, quod volunt, credunt.
Caesar, Civil War
2.27 (tr. A.G. Peskett):
For what we desire we gladly believe.
Nam, quae volumus, et credimus libenter.
Arrian, Anabasis of Alexander
1.7.3 (tr. P.A. Brunt)
In ignorance of the facts, they conjectured (as often happens in such cases) what they most desired.
ὅπερ φιλεῖ ἐν τοῖς τοιοῖσδε, οὐ γιγνώσκοντες τὰ ὄντα τὰ μάλιστα καθ᾽ ἡδονήν σφισιν εἴκαζον.