en the Thought is great and natural, we should, with Horace [2]
impute to a pardonable Inadvertency, or to the Weakness of human Nature,
which cannot attend to each minute Particular, and give the last
Finishing to every Circumstance in so long a Work. The Ancient Criticks
therefore, who were acted by a Spirit of Candour, rather than that of
Cavilling, invented certain Figures of Speech, on purpose to palliate
little Errors of this nature in the Writings of those Authors who had so
many greater Beauties to attone for them.

If Clearness and Perspicuity were only to be consulted, the Poet would
have nothing else to do but to cloath his Thoughts in the most plain and
natural Expressions. But since it often happens that the most obvious
Phrases, and those which are used in ordinary Conversation, become too
familiar to the Ear, and contract a kind of Meanness by passing through
the Mouths of the Vulgar, a Poet should take particular Care to guard
himself against Idiomatick Ways of Speaking. Ovid and Lucan have many
Poornesses of Expression upon this Account, as taking up with the first
Phrases that offered, without putting themselves to the Trouble of
looking after such as would not only have been natural, but also
elevated and sublime. Milton has but few Failings in this Kind, of
which, however, you may [meet with some Instances, as [3] in the
following Passages.

Embrios and Idiots, Eremites and Fryars,
White, Black, and Grey,--with all their Trumpery,
Here Pilgrims roam--

--A while discourse they hold,
No fear lest Dinner cool;--when thus began
Our Author--

Who of all Ages to succeed, but feeling
The Evil on him brought by me, will curse
My Head, ill fare our Ancestor impure,
For this we may thank Adam--

The Great Masters in Composition, knew very well that many an elegant
Phrase becomes improper for a Poet or an Orator, when it has been
debased by common Use. For this Reason the Works of Ancient Authors,
which are written in dead Languages, have a great Advantage over those
which are written in Languages that are now spoken. Were there any mean
Phrases or Idioms in Virgil and Homer, they would not shock the Ear of
the most delicate Modern Reader, so much as they would have done that of
an old Greek or Roman, because we never hear them pronounced in our
Streets, or in ordinary Conversation.

It is not therefore sufficient, that the Language of an Epic Poem be
Perspicuous, unless it be also