Why Is a Raven Like a Writing Desk?

According to the rec.arts.books FAQ, Lewis Carroll had no specific answer in mind for the riddle when he wrote Alice in Wonderland. As Cecil Adams at The Straight Dope points out, the joke is that there is no answer.

Ah, that Victorian wit, so very daft. The laudanum must have been kicking in about then, no?

Nevertheless, the power of riddles is such that the mind can't let go until some solution is found. And so, people have ventured and sought satisfactory answers to the riddle for some 140 years. Carroll himself, in the preface to the 1896 edition of Alice, wrote:

"Because it can produce a few notes, tho they are very flat; and it is nevar [sic] put with the wrong end in front!"

Note that "nevar" is "raven" backwards. Later editions have "corrected" the spelling, mainly because editing is a humorless process, as I know too well from experience.

Writer Aldous Huxley instead answered the riddle with, "Because there is a 'b' in 'both' and an 'n' in 'neither,'" which I find a much more satisfactory answer, especially in context of the scene and the character who delivers the line—that favorite of Victorian children and 60's acid-trippers alike, the Mad Hatter.

Unfortunately Huxley had to become dreary and follow this charming bit of nonsense with the observation that:

Such metaphysical questions as: "Does God exist?" "Do we have free will?" and, "Why is there suffering?" are as meaningless as the Mad Hatter's question—nonsensical riddles, questions not about reality but about words.

It can be such a burden to be clever, sometimes, eh Aldie? Too bad there wasn't any laudanum left for you.

Cyril Pearson suggests, in the 1907 Twentieth Century Standard Puzzle Book, that a raven is like a writing desk, "Because it slopes with a flap." Sam Loyd postulated two fine answers—"Because the notes for which they are noted are not noted for being musical notes," and, "Because Poe wrote on both." The rec.arts.books FAQ ascribes to David B. Jodrey, Jr. the answer, "Both have quills dipped in ink," which The Straight Dope reports as, "Because both have inky quills," a superior rendering of the idea. Stephen King, of all people (do we really need a link for Stephen King? How small exactly is that box in which you live?), answers the riddle thus in The Shining: "The higher the fewer, of course! Have another cup of tea!" Clever indeed.

And I do like the anonymous solution from The Straight Dope: "Because you cannot ride either one of them like a bicycle."

"Riddle," by the by, comes from the Old English rædels, meaning "opinion, counsel, conjecture, riddle," related to rædan, "to explain, rule, read, advise," from the root ræd–, meaning "advice." Rædan is also the root of the modern word "read."

Interestingly, the word "riddle" in the sense of "to perforate with many holes" comes from the Old English hridder meaning "sieve," and is related to the Proto-Germanic root *khrid–, meaning "to shake," and likely related (via Proto-Indo-European) to Latin cribrum meaning "sieve" and Greek krinein meaning "to separate, distinguish, decide." Krinein gives us the word "crisis."