so sensible of this Defect in the Subject of his Poem, and of the few Characters it would afford him, that he has brought into it two Actors of a Shadowy and Fictitious Nature, in the Persons of
Sin
and
Death
, by which means he has
wrought into
the Body of his Fable a very beautiful and well-invented Allegory. But notwithstanding the Fineness of this Allegory may attone for it in some measure; I cannot think that Persons of such a Chymerical Existence are proper Actors in an Epic Poem; because there is not that measure of Probability annexed to them, which is requisite in Writings of this kind,
as I shall shew more at large hereafter