Satan’s Walk upon the Outside of the Universe, which, at a Distance, appeared to him of a globular Form, but, upon his nearer Approach, looked like an unbounded Plain, is natural and noble:  As his Roaming upon the Frontiers of the Creation between that Mass of Matter, which was wrought into a World, and that shapeless unformed Heap of Materials, which still lay in Chaos and Confusion, strikes the Imagination with something astonishingly great and wild.  I have before spoken of the Limbo of Vanity, which the Poet places upon this outermost Surface of the Universe, and shall here explain my self more at large on that, and other Parts of the Poem, which are of the same Shadowy Nature.

Aristotle observes[1], that the Fable of an Epic Poem should abound in Circumstances that are both credible and astonishing; or as the French Criticks chuse to phrase it, the Fable should be filled with the Probable and the Marvellous.  This Rule is as fine and just as any in Aristotle’s whole Art of Poetry.

If the Fable is only Probable, it differs nothing from a true History; if it is only Marvellous, it is no better than a Romance.  The great Secret therefore of Heroic Poetry is to relate such Circumstances, as may produce in the Reader at the same time both Belief and Astonishment.  This is brought to pass in a well-chosen Fable, by the Account of such things as have really happened, or at least of such things as have happened according to the received Opinions of Mankind.  Milton’s Fable is a Masterpiece of this Nature; as the War in Heaven, the Condition of the fallen Angels, the State of Innocence, and Temptation of the Serpent, and the Fall of Man, though they are very astonishing in themselves, are not only credible, but actual Points of Faith.

The next Method of reconciling Miracles with Credibility, is by a happy Invention of the Poet; as in particular, when he introduces Agents of a superior Nature, who are capable of effecting what is wonderful, and what is not to be met with in the ordinary course of things.  Ulysses’s Ship being turned into a Rock, and AEneas’s Fleet into a Shoal of Water Nymphs; though they are very surprising Accidents, are nevertheless probable, when we are told that they were the Gods who thus transformed them.  It is this kind of Machinery which fills the Poems both of Homer and Virgil with such Circumstances as are wonderful, but not impossible, and so frequently produce in the Reader the most pleasing Passion that can rise in the Mind of Man, which is Admiration.  If there be any Instance in the AEneid liable to Exception upon this Account, it is in the Beginning of the Third Book, where AEneas is represented as tearing up the Myrtle that dropped Blood.  To qualifie this wonderful Circumstance, Polydorus tells a Story from the Root of the Myrtle, that the barbarous Inhabitants of the Country having pierced him with Spears and Arrows, the Wood which was left in his Body took Root in his Wounds, and gave Birth to that bleeding Tree.