The "Art of Poetry"

"Simul et jucunda et idonea dicere vitae."
(Horace, Art of Poetry)

"To teach - to please - comprise the poet's views,
Or else at once to profit and amuse."
(Howe's translation)

"Two objects always should the poet move,
Or one or both, - to please or to improve."
(Byron's translation, in Hints from Horace)

"ut pictora poesis"
(Horace)

"in poetry as in painting"
(anonymous translation)