Therefore let Pastoral be smooth and soft, not noisy and bombast; lest whilst it raiseth its voice, and opens its mouth, it meet with the same fate that, they say, an Italian Shepherd did, who having a very large mouth, and a very strong breath, brake his Pipe as often as he blow’d it.  This is a great fault in one that writes Pastorals:  for if his words are too sounding, or his sense too strong, he must be absurd, because indecently loud.  And this is not the rule of an unskilful {54} impertinent Adviser, but rather of a very excellent Master in this Art; for Phoebus twitcht Virgil by the Ear, and warn’d him to forbear great Subjects:  but if it ventures upon such, it may be allow’d to use some short Invocations, and, as Epicks do, modestly implore the assistance of a Muse.  This Virgil doth in his Pollio, which is a Composure of an unusual loftiness: 

  Sicilian Muse begin a loftier strain.

So he invocates Arethusa, when Cornelius Gallus Proconsul of AEgypt and his Amours, matters above the common reach of Pastoral, are his Subject.

  One Labor more O Arethusa yield.

Why he makes his application to Aretheusa is easy to conjecture, for she was a Nymph of Sicily, and so he might hope that she could inspire him with a Genius fit for Pastorals which first began in that Island, Thus in the seventh and eighth Eclogue, as the matter would bear, he invocates the Nymphs and Muses:  And Theocritus does the same,

  Tell Goddess, you can tell.

From whence ’tis evident that in Pastoral, tho it never pretends to any greatness, Invocations {55} may be allow’d:  But whatever Subject it chooseth, it must take care to accommodate it to the Genius and Circumstances of a Shepherd.

Concerning the Form, or mode of Imitation, I shall not repeat what I have already said, viz. that this is in it self mixt; for Pastoral is either Alternate, or hath but one Person, or is mixt of both:  yet ’tis properly and chiefly Alternate. as is evident from that of Theocritus.

  Sing Rural strains, for as we march along
  We may delight each other with a Song.

In which the Poet shows that alternate singing is proper to a Pastoral:  But as for the Fable, ’tis requisite that it should be simple, lest in stead of Pastoral it put on the form of a Comedy, or Tragedy if the Fable be great, or intricate:  It must be One; this Aristotle thinks necessary in every Poem, and Horace lays down this general Rule,

  Be every Fable simple, and but one: 

For every Poem, that is not One, is imperfect, and this Unity is to be taken from the Action:  for if that is One, the Poem will be so too.  Such is the Passion of Corydon in Virgil’s second Eclogue, Meliboeus’s Expostulation with Tityrus about his Fortune; Theocritus’s Thyrsis, Cyclops, and Amaryllis, of which perhaps in its proper place I may treat more largely.