Indeed, so little does poetry depend for its effect on the power of raising sensible images, that I am convinced it would lose a very considerable part of its energy, if this were the necessary result of all description.

Because that union of affecting words, which is the most powerful of all poetical instruments, would frequently lose its force along with its propriety and consistency, if the sensible images were always excited.

There is not, perhaps, in the whole AEneid a more grand and labored passage than the description of Vulcan's cavern in Etna, and the works that are there carried on.

Virgil dwells particularly on the formation of the thunder which he describes unfinished under the hammers of the Cyclops.

But what are the principles of this extraordinary composition?
Tres imbris torti radios, tres nubis aquosae Addiderant; rutili tres ignis, et alitis austri: Fulgores nunc terrificos, sonitumque, metumque Miscebant operi, flammisque sequacibus iras.
This seems to me admirably sublime: yet if we attend coolly to the kind of sensible images which a combination of ideas of this sort must form, the chimeras of madmen cannot appear more wild and absurd than such a picture.