When I speak fiction, be it such fiction as persuades the listener's ear!
ψευδοίμην· ἀίοντος ἅ κεν πεπίθοιεν ἀκουήν.
Original text (Ancient Greek)
Notes from Wikiquote
A poet's fiction should at least be plausible. | II. To Apollo
Variants
(S. Lombardo, D. Rayor, 1988)