While on its surface, "Ars Poetica" is quite simple, there are many complexities in the poem that the reader will have to grapple with to understand its essence. The title of the poem is borrowed from Horace (a lyric poet of ancient Rome), and it means "the art of poetry." The title hence sets a clear precedent for what is to follow in the poem; namely, an official—though poetic—manifesto about what the speaker thinks of poetry as an art. As a modernist manifesto, the poem does not really adhere to any one set of conventions, but alternates in its use of rhyme, meter, syntax, punctuation and grammar.
According to the speaker, a poem should be sensory and concrete, as well as silent, like a round fruit. It should be unthinking or natural, like a person playing with a medallion in their hand. The poem should be as silent as a window ledge overgrown with moss. A poem should be wordless, like a bird in flight. It should be both still and moving, simultaneously leaving and staying in the mind like memories do, or like the moon which both rises and is stationary in the sky. Perhaps these lines also mean that a poem should reveal and conceal, like the moon lights the trees and hangs behind the winter leaves, rendering them black. The speaker repeats the stanza about the moon climbing, reiterating that a poem should contain these qualities of the moon. Then, he says, a poem should be equal to a thing, rather than a true statement about it. A poem should also leave one with cryptic traces—like if all the history of people grieving only left humanity with an empty doorway and a maple leaf, or as if love only left some grasses that leaned and lights that were visible over the ocean. Finally, the speaker says, a poem should not mean anything, but should simply exist.