William Butler Yeats Quote

At midnight on the Emperor's pavement flit
Flames that no faggot feeds, nor steel has lit,
Nor storm disturbs, flames begotten of flame,
Where blood-begotten spirits come
And all complexities of fury leave,
Dying into a dance,
An agony of trance,
An agony of flame that cannot singe a sleeve.

Byzantium, st. 4 - The Winding Stair and Other Poems (1933)