If you come across another MacLeish poem, chances are you'll feel as if you've got both feet in two separate worlds of old and new. Our man did a lot of his best writing during the first World War, and in his work you often get the sense of MacLeish trying to blend the ideal with the real. In other words, things back then looked awfully confusing and disconcerting, but MacLeish still had a drive to at least imagine a more ideal world in his poetry. And how did he often depict and talk about the ideal? In the form of art, of course.
His poems therefore tend to sound mighty metaphysical and rely on imagery more than anything else, like that in "Ars Poetica." His speakers often lift us out of the physical world and bring us into something more symbolic and transformative through those images. You might also hear a lot of talk about the soul and spirit, again sounding mighty metaphysical. Check out these MacLeish gems for a better idea: "Charity," "Soul-Sight," and "An Eternity."