Vt pictura poesis: erit quae, si propius stes,
te capiat magis, et quaedam, si longius abstes.
haec amat obscurum, volet haec sub luce videri,
iudicis argutum quae non formidat acumen;
haec placuit semel, haec deciens repetita placebit.
(Horace, Ep. 2.3.361-5)
A poem is like a picture: one strikes your fancy more, the nearer you stand; another, the farther away. This courts the shade, that will wish to be seen in the light, and dreads not the critic insight of the judge. This pleased but once; that, though ten times called for, will always please. (tr. H. Rushton Fairclough)