“O Romeo, Romeo, wherefore art thou Romeo?
Deny thy father and refuse thy name;
Or if thou wilt not, be but sworn my love
And I’ll no longer be a Capulet.”

When Shakespeare’s Juliet utters her anguished words — in possibly one of the most quoted and most misunderstood lines in English literature — she is asking her beloved not where he is (as might be suggested by the word wherefore), but why he is who he is.  It is because of the feud between the families into which they were respectively born that their love for each other is beyond the bounds of possibility; why, Juliet asks, did Romeo have to be a Montague? Wherefore is an archaic conjunctive adverb, dating back to Middle English, meaning “why”, “for what reason”, “because of what”. Percy Shelley seemed to like making use of the poetic interrogative, as evidenced in his revolutionary poem A Song to the Men of England, in which he asks repeatedly why the English workers don’t rise up and question their masters and oppressors.  Here are the first three stanzas:

Men of England, wherefore plough
For the lords who lay ye low?
Wherefore weave with toil and care
The rich robes your tyrants wear?

Wherefore feed and clothe and save
From the cradle to the grave
Those ungrateful drones who would
Drain your sweat—nay, drink your blood?

Wherefore, Bees of England, forge
Many a weapon, chain, and scourge,
That these stingless drones may spoil
The forced produce of your toil?

Wherefore was also used not just to start a question, but also as a synonym of and more formal alternative to the adverb therefore (meaning “as a result”, “on which account”, “for this reason”). “The rain was falling, and wherefore we sought shelter.”

It’s in its third incarnation, as a noun meaning reason or explanation, that wherefore has survived the longest and remains in current usage, in the expression “whys and wherefores”. Curiously, neither of the words in this tautologous phrase generally goes out in public except in the other’s company (either reasons or causes would normally step in for whys or wherefores on its own), and they really only work as nouns in their plural form (rarely would you hear about a single why or wherefore). But there is a notable exception: Gilbert & Sullivan, in their jaunty song from H.M.S. Pinafore, tell us not to question why love is blind to rank, class and station. Wherefore did they choose this singular version of the phrase? Never mind the whys and wherefores …

Never mind the why and wherefore,
Love can level ranks, and therefore,
Though his lordship’s station’s mighty,
Though stupendous be his brain,
Though your tastes are mean and flighty
And your fortune poor and plain.

— Gilbert & Sullivan, HMS Pinafore