Johnson substituted the following, and Crabbe accepted the revised
version:--

"On Mincio's banks, in Caesar's bounteous reign,
If Tityrus found the Golden Age again,
Must sleepy bards the flattering dream prolong,
Mechanic echoes of the Mantuan song?
From Truth and Nature shall we widely stray,
Where Virgil, not where Fancy, leads the way?"

The first four lines of Johnson are beyond question an improvement, and
it is worth remark in passing how in the fourth line he has anticipated
Cowper's "made poetry a mere mechanic art."

But in the concluding couplet, Crabbe's meaning seems to lose in
clearness through the change. Crabbe intended to ask whether it was safe
to desert truth and nature for one's own self-pleasing fancies, even
though Virgil had set the example. Johnson's version seems to obscure
rather than to make clearer this interpretation. Crabbe, after this
protest against the conventional, which, if unreal at the outset, had
become a thousand times more wearisome by repetition, passes on to a
daring presentation of real life lived among all the squalor of actual
poverty, not unskilfully interspersed with descriptions equally faithful
of the barren coast-scenery among which he had been brought up. It has
been already remarked how Crabbe's eye for rural nature had been
quickened and made more exact by his studies in botany. There was little
in the poetry then popular that reproduced an actual scene as perfectly
as do the following lines:--

"Lo! where the heath, with withering brake grown o'er,