No More Learning

It by no means follows, however, that the
incitements of Passion' or the precepts of Duty, or even the lessons of
Truth, may not be introduced into a poem, and with advantage; for they
may subserve incidentally, in various ways, the general purposes of
the work: but the true artist will always contrive to tone them down in
proper           to that _Beauty _which is the atmosphere and the real
essence of the poem.