Returning from its daily quest, my Spirit
Changed thoughts and vile in thee doth weep to find:
It grieves me that thy mild and gentle mind
Those ample virtues which it did inherit
Has lost. Once thou didst loathe the multitude
Of blind and madding men--I then loved thee--
I loved thy lofty songs and that sweet mood
When thou wert faithful to thyself and me
I dare not now through thy degraded state
Own the delight thy strains inspire--in vain
I seek what once thou wert--we cannot meet
And we were wont. Again and yet again
Ponder my words: so the false Spirit shall fly
And leave to thee thy true integrity.

Percy Bysshe Shelley

http://www.poemhunter.com/poem/sonnet-from-the-italian-of-cavalcanti/