Why do you think Kingsolver chose lines from Wallace Steven's "The Well Dressed Man with a Beard" for the epigraph?

Why do you think Kingsolver chose lines from Wallace Steven's "The Well Dressed Man with a Beard" for the epigraph?

After the final no there comes a yes
And on that yes the future world depends

I interpret these lines as a coda to Tig's conversation with Willa in the cemetery: after any of us stop resisting the reality of our endangered planet and its roots in our perverted economy ( the "final no") we can begin building a community, a more hopeful future, through our creative problem solving, our re-use of resources, our changed priorities and willingness to embrace diversity and sharing (i"that yes on which the future world depends"). It's the major theme of this novel, which in my opinion is Kingsolver's most compelling expression of the message in all of her work.

I agree with the response above. This is the theme of the novel and it is rephrased by the characters repeatedly throughout the book.