Perverse, delicious, competitive

What has four legs in the morning, two legs in the afternoon, and three legs in the evening? This was the riddle of the Sphinx, a monster with the head of a woman and the winged body of a lion who terrorised the city of Thebes. It was the limping wanderer Oedipus who finally answered “man”, and in return he was made king of the city, and given his mother, Jocasta, as wife. Oops. It’s not always a good idea to solve riddles.

The English word “riddle” seems to be cognate with an old word for “sieve”, fittingly: the riddle sifts and discriminates, sorting the men who can solve it from the boys who can’t. And this has exerted a seductive power since the dawn of words themselves: the riddle can claim to be the oldest literary form of all. Once the play instinct kicks in, and language begins to toy with itself, riddles are inevitable.

The trickiest sort of riddle doesn’t even confess its puzzling nature: let’s call it the Riddle Perverse. Croesus was told by the Delphic oracle that he would “destroy a great realm” if he crossed the river Halys to attack the Persians. Excellent, he thought, rubbing his hands, and realising too late that the destruction would be his own. Macbeth famously imagined that the witches’ prophecy of his defeat “when Birnham wood comes to Dunsinane” was just a fancy way of saying it would never happen.

A riddle can be fatal to lesser men than heroes, but it can also be a pure diversion, cake for the brain: the Riddle Delicious. Ancient Rome was home to a cadre of professional riddlers to tickle the fancies of noblemen. Later on, men of God, such as the seventh-century English bishop Aldhelm, composed widely circulated books of Latin riddles in careful hexameter. Perhaps by marvelling at them, the pious could also be moved to greater wonder at God’s creation.

Riddling has even been used as a sublimation of the martial instinct: the Riddle Competitive. Samson challenged the Philistines to figure out what he meant by “Out of the eater came forth meat, and out of the strong came forth sweetness” – and won 30 sheets and 30 changes of clothes from his baffled foes. (The strongman had killed a lion with his bare hands and discovered a beehive dripping with honey inside.) And a 14th-century history tells us about a war of riddles that raged between the kings of Babylon and of Egypt: the former always won, because he had Aesop, the clever fabulist, in his court.

The 18th century saw riddles becoming fashionable among the wits of the French court, and even serious thinkers like Voltaire and Rousseau. Now riddles reacquired a literary cachet of their own. A riddle, after all, is a description which is perfectly true, but couched in distractingly figurative language. The art of riddling is thus a highly poetic one – indeed, Aristotle had pointed out in his Rhetoric that riddling could be a rich source of new metaphors.

Sure enough, the French fashion spread to England, and poets such as Cowper and Swift composed amusing riddles for magazines, which largely invited admiration for their ingenuity of expression more than for their difficulty: the Riddle Poetic. Swift’s “I with borrowed silver shine, / What you see is none of mine…”, for instance, fairly obviously describes the moon, but delights with its imagistic invention.

Lewis Carroll of course loved riddles (he made a character out of Humpty Dumpty, subject of a traditional children’s riddle about an egg), and riddles’ playful philosophy certainly informed the group of marvellously abstruse 20th-century French writers, OuLiPo. Georges Perec’s celebrated novel, La Disparition, is a gigantic riddle in itself: the Riddle Leviathan. Its first reviewers failed utterly to notice that the letter “e” was never used. (One lovely theory about the novel is that it is a massively indirect way of saying “eux”, or “they”, referring to the victims of the Holocaust.)

But by then riddles had already reclaimed their place in narrative itself, becoming the meat of detective fiction from Edgar Allan Poe onwards. The mystery of the locked room in “The Murders of the Rue Morgue”, for instance, is twice referred to directly as a “riddle” by the hero Auguste Dupin. From Dupin to Holmes and Poirot, the riddle is again, as it was in classical myth, the Riddle Heroic: a test of the protagonist’s mental superiority.

Riddles even crop up in pop music: Bob Dylan’s lyrics have an aura of compact enigma, so that torrents of literary study may be devoted to decoding them. And we mustn’t forget 1980s hairstyle-on-a-stick Nik Kershaw, who blatantly released a single called “The Riddle” (sing along now: “Near a tree by a river there’s a hole in the ground / Where an old man of Arran goes around and around”) — its hidden meaning may well be eternally (and thankfully) deferred.

From Greek myth to modern-day breakfast tables (cryptic crossword clues, of course, are riddles): there seems to be an eternal human delight in head-scratching over verbal conundrums. And the harder the better, as a line of puzzle-loving poet Emily Dickinson’s insists: “The Riddle we can guess / We speedily despise.” So to keep you on your toes, here is the riddle that, according to apocryphal legend, caused Homer to die of vexation because he couldn’t solve it. “What we caught we threw away, what we could not catch we kept.” Riddle me that.