Verisimilitude, Poetry. The first rule that the poet must observe, in treating the subjects s/he has chosen, is to insert nothing that could be against verisimilitude . A verisimilar fact is a fact possible in the circumstances where one puts it on stage. Fictions without verisimilitude and an excess of prodigious events, disgust readers of educated judgment. There are many things, says a great critic, where poets and painters can make a career with their imagination; it is not always necessary to restrict them with narrow and rigorous reason; But they are not permitted to mix incompatible things, to couple birds with serpents, tigers with lambs.

Sed non ut placidis coeant immitia, non ut Serpentes avibus geminentur, tigribus agni. [But not so far that savage should mate with tame, or serpents couple with birds, lambs with tigers.] Art poétique v. 14. [1]

If such revolting license is defended by the poets, on the other hand, the events where nothing surprising reigns appear flat, be it by the nobility of sentiment, be it by the precision of thought, be it by the trueness of expression. The alliance of the marvelous and the verisimilar, where the former and the latter hardly lose their rights, is a talent that distinguishes poets in the class of Virgil, the verse writers [versificators] without invention, and the extravagant poets. However a poem without wonders displeases even more than a poem based on a supposition without verisimilitude .

Nothing destroys verisimilitude more than a fact, the sure knowledge that a spectator can have, that the event has happened other than the way that the poet is telling it; the poets who in their works contradict well-known historical events, detract very much from the verisimilitude of their fictions. I know very well that the false is sometimes more verisimilar than the true, but we do not regulate our belief of the events on their metaphysical verisimilitude , nor on faith in their possibility; it is on the historical verisimilitude . We do not examine what should more probably happen, but what the necessary witnesses and what the historians tell; and it is their narrative, and not the verisimilar , that determines our belief. So we do not believe the event that is the most verisimilar and the most possible, but what they tell us had truly happened. Their deposition ruling our belief of the facts, that which can be contrary to their deposition could not appear verisimilar; For as the truth is the soul of history, verisimilitude is the soul of poetry.

Nevertheless, I do not deny that there are not some theatrical verisimilitudes , for example in opera, that one is obliged to take part in; in granting this liberty to the poets, one is paid by the beauties that liberty can produce. There are verisimilitudes of another kind for the epic; however this same genre must convey with skill and genius the most verisimilar suppositions as is possible, as Virgil did to compensate for the strangeness of the enormous horse that the Greeks decided to construct in order to make themselves masters of Troy.

These reflections will suffice on verisimilitude in general. The particular question of dramatic verisimilitude has been handled with the word Dramatic Poetry.

1. Horace, Ars Poetica , Loeb Classical Library No. 194, verse 14.