For 10 points, name this Irish poet of "Sailing to Byzantium" and "The Second Coming".
This author wrote that "an aged man is but a paltry thing" in one of his poems. This poet wrote that "a terrible beauty is born" in "Easter, 1916" and he saw a "vast image out of Spiritus Mundi" in another poem. This author leaves a place that is "no country for old men" in one of his poems, and described a "rough beast slouching towards Bethlehem" in another. That poem notes that "the center cannot hold."  For 10 points, name this Irish poet of "Sailing to Byzantium" and "The Second Coming".
This author wrote that "an aged man is but a paltry thing" in one of his poems.
William Butler {Yeats}