The Inaugural Oratory post below has gotten some criticism for the author's use of "from whence." One blog admonishes, "I don't mean to misundere[s]timate you, David, but there is no such thing as 'from whence.' 'Whence' means 'from where.'" I too had long taken a similar view, and this is apparently a common view, judging by this column.
But the Oxford English Dictionary cites examples of "from whence" from Dryden, Dickens, and Swinburne. Even those not blessed with free OED access can do a quick search through Project Gutenberg to find examples from Shakespeare, Dickens, and who knows how many others. To be sure, "from whence" isn't the phrase I'd choose as a stylistic matter. But it's hard to see under what meaning of "there is no such thing" one can say "there is no such thing as 'from whence'" (unless "there is no such thing as" is an odd way of saying "I don't like").
Now doubtless this can lead us to the usual debates about descriptivism and prescriptivism. But I wonder whether we might finesse those debates here using the sheer volume of evidence that "from whence" has been used by great English writers. Here's my argument, which I think should be sufficient to support my point, though not necessary: If someone can point to evidence that a phrase was used as standard in edited text by Shakespeare, Dickens, Dryden, and more, then that phrase is presumptively permissible unless its critics can point to some authority of comparable credibility that explains why the phrase is incorrect. Surely even prescriptivists would want to see evidence that a prescription is authoritative, rather than deferring to any prescription that anyone happens to pronounce.
I should also add that abstract logic of the "it's redundant" sort can't count, because redundancy is not itself a sign of linguistic error. For instance, "null and void" may be redundant, and may be poor style as a result, but there's nothing incorrect about it. What's more, standard usage sometimes requires redundancy: "I am typing" conveys the identity of the actor twice — in the "I" and the "am" — but it's not therefore nonstandard, and in fact the less redundant "am typing" is what is highly nonstandard. (Not so in other languages, in which one can avoid redundancy of the "I am typing" variety, but that just shows that the standard in language is a function of usage, not of abstract logic.)
Finally, I should stress again that none of this resolves whether "from whence" is elegant or not (or for that matter the separate question of whether "from whence" is an apt way of saying "from which" in contexts where there's no sense of movement or origination). The American Heritage Dictionary, for instance, reports,
The construction from whence has been criticized as redundant since the 18th century. It is true that whence incorporates the sense of from: a remote village, whence little news reached the wider world. But from whence has been used steadily by reputable writers since the 14th century, most notably in the King James Bible: "I will lift up mine eyes unto the hills, from whence cometh my help" (Psalms). Such a respectable precedent makes it difficult to label the construction as incorrect. Still, it may be observed that whence (like thence) is most often used nowadays to impart an archaic or highly formal tone to a passage, and that this effect is probably better realized if the archaic syntax of the word — without from — is preserved as well.
And this may well be wise advice (though it's not clear, given the dictionary's own evidence, that plain "whence" is much more archaic than "from whence"). But that's a different matter from the question whether a certain usage is wrong (which I take it is what was meant by "there is no such thing").