Possible Duplicate:
Is “from whence” correct? Or should it be “whence”?
From the Shakespeare's Sonnet XLVIII,
...
From whence at pleasure thou mayst come and part;
And even thence thou wilt be stol'n I fear,
For truth proves thievish for a prize so dear.
Isn't the definition of whence is "from where" or "from what place" which when converted from the phrase above will be "From from where at pleasure..."? Does Shakespeare use the word whence incorrectly?