What are the binary oppositions in W.B.Yeats's "The Second Coming"?

Part of what makes Yeats' poem so powerful is that he
plays into and yet rejects the binary opposition that is so much a part of Western
intellectual currents.  Had Yeats taken the traditional approach to binary thought, he
would have presented it as "either or."  He undermines this by presenting a vision where
pain is inevitable in either realm.  It is "either and or" as human suffering is present
in either case.  From the opening lines, we can see this.  When the "falcon cannot hear
the falconer" or when "the center cannot hold/ mere anarchy is loosed upon the world,"
we are given binary oppositions ("falcon" and "falconer" or "center" and "anarchy.") 
Yet, in both settings, there can be no refuge taken because of what lies ahead.  When
Yeats describes the figure that arises in front of him, it is a vision that eliminates
the binary opposition in the first stanza.  What ends up becoming horrifying is that
this vision crushes everything in its path, eliminating any hope of sanctuary that
binary opposing thought could or had provided.  In this light, Yeats plays with and
evokes the binary oppositions that had become a part of our identity and replaces it
with a vision that forces reckoning as it eliminates them.  In this light, the poem
moves from a modernist work to something that foreshadows the post- modernist
movement.