I must observe also, that as Virgil, in the Poem which was designed to celebrate the Original of the Roman Empire, has described the Birth of its great Rival, the Carthaginian Commonwealth:  Milton, with the like Art, in his Poem on the Fall of Man, has related the Fall of those Angels who are his professed Enemies.  Besides the many other Beauties in such an Episode, its running parallel with the great Action of the Poem hinders it from breaking the Unity so much as another Episode would have done, that had not so great an Affinity with the principal Subject.  In short, this is the same kind of Beauty which the Criticks admire in The Spanish Frier, or The Double Discovery [13] where the two different Plots look like Counter-parts and Copies of one another.

The second Qualification required in the Action of an Epic Poem, is, that it should be an entire Action:  An Action is entire when it is complete in all its Parts; or, as Aristotle describes it, when it consists of a Beginning, a Middle, and an End.  Nothing should go before it, be intermixed with it, or follow after it, that is not related to it.  As on the contrary, no single Step should be omitted in that just and regular Progress which it must be supposed to take from its Original to its Consummation.  Thus we see the Anger of Achilles in its Birth, its Continuance and Effects; and AEneas’s Settlement in Italy, carried on thro all the Oppositions in his Way to it both by Sea and Land.  The Action in Milton excels (I think) both the former in this Particular; we see it contrived in Hell, executed upon Earth, and punished by Heaven.  The Parts of it are told in the most distinct Manner, and grow out of one another in the most natural [Order [14]].

The third Qualification of an Epic Poem is its Greatness.  The Anger of Achilles was of such Consequence, that it embroiled the Kings of Greece, destroyed the Heroes of Troy, and engaged all the Gods in Factions. AEneas’s Settlement in Italy produced the Caesars, and gave Birth to the Roman Empire. Milton’s Subject was still greater than either of the former; it does not determine the Fate of single Persons or Nations, but of a whole Species.  The united Powers of Hell are joined together for the Destruction of Mankind, which they affected in part, and would have completed, had not Omnipotence it self interposed.  The principal Actors are Man in his greatest Perfection, and Woman in her highest Beauty.  Their Enemies are the fallen Angels:  The Messiah their Friend, and the Almighty their Protector.  In short, every thing that is great in the whole Circle of Being, whether within the Verge of Nature, or out of it, has a proper Part assigned it in this noble Poem.