I am not resigned to the shutting away of loving hearts in the hard ground.
So it is, and so it will be, for so it has been, time out of mind:
Into the darkness they go, the wise and the lovely.  Crowned
With lilies and with laurel they go; but I am not resigned.
“I am not resigned” becomes a kind of insistent  refrain  (repeated tag phrase) throughout the poem. 
 Millay sets the poem up as an elegy, or lament, not for one dead person in particular but for the cruel destructiveness of death in general.
Dirge Without Music