Poetry should treat
Of lofty things
Soaring thoughts
And birds with wings.
The Muse of Poetry
Should not know
That roses
In manure grow.
The Muse of Poetry
Should not care
That earthly pain
Juxtaposition. Hughes uses this line to show that beautiful things, such as poetry, that affect those who observe them often are born from circumstances that are not socially acceptable to talk about. Hughes echoes this idea in  Call to Creation  without using the sarcastic tone that he assumes throughout this poem. In both poems, Hughes reminds the reader that there are bad things that happen every day, and the dark moments of our history cannot be ignored. 
 This line also makes me think of the Outkast song, Roses.
Formula