Analysis of To a Friend

I ask but one thing of you, only one,
That always you will be my dream of you;
That never shall I wake to find untrue
All this I have believed and rested on,
Forever vanished, like a vision gone
Out into the night. Alas, how few
There are who strike in us a chord we knew
Existed, but so seldom heard its tone
We tremble at the half-forgotten sound.
The world is full of rude awakenings
And heaven-born castles shattered to the ground,
Yet still our human longing vainly clings
To a belief in beauty through all wrongs.
O stay your hand, and leave my heart its songs!