What light is light, if Sylvia be not seen?
What joy is joy, if Sylvia be not by?
Unless it be to think that she is by,
And feed upon the shadow of perfection.
Except I be by Sylvia in the night,
There is no music in the nightingale;
Unless I look on Sylvia in the day,
There is no day for me to look upon.
She is my essence, and I leave to be
If I be not by her fair influence
Foster’d, illumin’d, cherish’d, kept alive.
taken from Two Gentlemen of Verona by William Shakespeare
it stucks in my head :p