Allegory, or the personification of invisible physic and metaphysic ideas, though not banished from the regions of Invention, is equally inadmissible in pure epic, dramatic, and historic plans, because, wherever it enters, it must rule the whole.[81] It rules with propriety the mystic drama of the Vatican, where the characters displayed are only the varied instruments of a mystery by which the church was established, and Julio and Leone are the allegoric image, the representatives of that church; but the epic, dramatic, and historic painter embellish with poetry or delineate with truth what either was or is supposed to be real; they must therefore conduct their plans by personal and substantial agency, if they mean to excite that credibility, without which it is not in their power to create an interest in the spectator or the reader. That great principle, the necessity of a moral tendency or of some doctrine useful to mankind in the _whole_ of an epic performance, admitted, are we therefore to sacrifice the uniformity of its parts, and thus to lose that credibility which _alone_ can impress us with the importance of the maxim that dictated to the poet narration and to the artist imagery? Are the agents sometimes to be real beings, and sometimes abstract ideas? Is the Zeus of Homer, of whose almighty will the bard, at the very threshold of his poem, proclaims himself only the herald, by the purblind acuteness of a commentator, to be turned into æther; and Juno, just arriving from her celestial toilet, changed into air, to procure from their mystic embraces the allegoric offspring of vernal impregnation? When Minerva, by her weight, makes the chariot of Diomede groan, and Mars wounded, roars with the voice of ten thousand, are they nothing but the symbol of military discipline, and the sound of the battle's roar? or Ate, seized by her hair, and by Zeus dashed from the battlements of heaven, is she only a metaphysic idea? Forbid it, Sense! As well might we say, that Milton, when he called the porteress of hell, Satan's daughter, _Sin_, and his son and dread antagonist, _Death_, meant only to impress us with ideas of privation and nonentity, and sacrificed the real agents of his poem to an unskilful choice of names? Yet it is their name that has bewildered his commentator and biographer in criticisms equally cold, repugnant and incongruous, on the admissibility and inadmissibility of allegory in poems of supposed reality. What becomes of the interest the poet and the artist mean to excite in us, if, in the moment of reading or contemplating, we do not believe what the one tells and the other shows? It is that magic which places on the same basis of existence, and amalgamates the mythic or superhuman, and the human parts of the Ilias, of Paradise Lost, and of the Sistine Chapel, that enraptures, agitates, and whirls us along as readers or spectators.