I sat in a pew in a church in West Beirut, listening intently. The Eastern Catholic Mass was in Arabic, with parts of the liturgy intoned in Syriac—a descendent of Aramaic, the closest thing we have to Jesus’ vernacular. Only during the homily was I able to zero in on recognizable Arabic words—numbers, a few nouns, pronouns, connectives—and identify verb and adjective endings where I didn’t know the meaning of the root. It was an exercise whose intellectual mood was annihilated when the congregation rose to chant the Nicene Creed in Arabic, which was simultaneously opaque and exotic and uncanny to my ear, yet decipherable from its sequence in the Mass. Ritual made it almost transparent.

It was only afterward that my hosts explained it was Pentecost Sunday—the feast commemorating the descent of the Holy Spirit on the Apostles, manifested in their sudden, marvelous ability to proselytize in foreign languages. Theologically, this was the mystical resolution to the calamity of Babel—that failed attempt to touch heaven, which resulted in the inception of mutually incomprehensible languages. A punishment.

I had no Pentecostal miracle to report—knowledge of Arabic and Syriac didn’t magically descend on me—but the occasion dovetailed nicely with my previous week’s reading, Secret Language: Codes, Tricks, Spies, Thieves, and Symbols (Oxford; $24.95). It had set me up to think about obliqueness—how and when and why we mask our meanings. Barry J. Blake, a linguist and professor emeritus at La Trobe University, covers a lot of ground in Secret Language, enumerating the small word games we play with raw textual materials (anagrams, lipograms, palindromes, semordnilaps, acrostics) and working up to semantic games (riddles, ciphers). He includes chapters on argots, slang and "the everyday oblique" (humor, seduction, politeness). And while he sets forth numerous motivations for coding, or enciphering, or euphemizing, or just plain circuitousness, he thinks much of it arises from innate superstition: "Belief in the supernatural accounts for some of the strongest constraints on straightforward communication…. In many cultures certain words and phrases cannot be used for fear of offending a god or spirit and inviting retribution, while conversely some words and phrases are thought to have the power to enlist supernatural intervention in the physical world."

Blake would not be surprised to hear that my ritual for warding off fear during air travel is to start a New York Times crossword puzzle (Friday or Saturday’s, preferably) at takeoff. He would probably recommend cryptic crosswords for maximum absorption: their clues "tend to refer to the sequence of letters that make up a word rather than to the meaning. For instance, the clue might be ‘Stop a left in headgear.’ To get the answer, halt, you need to put ‘l’ for ‘left’ inside ‘hat,’ rather than looking for a word that means to block a left (punch) with a hat or a cap." Early producers of cryptic crosswords assumed pseudonyms from the Grand Inquisitors of the Spanish Inquisition. There’s a clear link between modern, anodyne brainteasers and the practices of Kabbalists and priests, like gematria (the study of the numerical properties of words) and notarikon (the search for hidden acrostics in divine texts).

Even today, religious practices may inform our first experience of codes. Prayers are a type of poetry; parables introduce us to metaphor; liturgical rites imbue us with the magic of structures. But even before we learned our prayers, our mothers recited nursery rhymes and sang lullabies, which too are codes: How I wonder what you are. And maybe we also had a foreign language or two in our background—a grandfather we didn’t understand, a mother who code-switched. We carry around with us a primal memory of emerging from the linguistic fog into enlightenment. Playing hide-and-seek with language recapitulates this memory.

Of course, secret languages can have practical stakes: underworld figures use argot to plot heists; spies and military officials encrypt classified intelligence. The history of codes is as deeply intertwined with rulers and generals as with priests: solving riddles was one of the feats expected of a hero. Alexander the Great, in the middle of his siege of Tyre, dreamed of a satyr; it was a good omen because the word satyros contained the message "Sa Tyros," or "Tyre is yours." It isn’t much of a leap from that to contemporary military euphemisms—think of "collateral damage." From ancient scytales to Enigma machines, codes have been enlisted to win wars.

But what value does oblique language have for us outside the battlefield and the shrine? If we all spoke to one another in the clear, direct speech of the newscaster (Blake’s example of the lowest end of the obscurity spectrum), then we could hardly crack a joke (which relies on double-entendres), or avoid rudeness (taboo words often involve bodily functions), or identify with our tribe (slang and jargon supply crucial social information) or use an idiom (those circumlocutions which we call "colorful language"). The truth is, we are a culture in flight from verbal color. The metaphoric and the riddling have been features of English-language literature from The Exeter Book to "I heard a fly buzz/when I died" to Pilgrim at Tinker Creek, but they tack against the prevailing winds of plain style. The journalistic credo of simple sentences and basic English has made it a crime against the language to use "fifty-cent words;" even the semi-colon is semi-demonized as an abettor of complex sentence structure. We fetishize the notion of verbal richness in, say, Shakespeare, but our true idol is Strunk and White. Yet it could be argued that that too is a code—for a particular world-view that fancies itself neutral, objective and elite.

Blake is Australian, not American. An expert in aboriginal languages, he points out how important indirect modes of discourse are for other societies. For the Kiriwana of the Trobriand Islands, "oblique speech is the norm and direct expression of criticism or difference of opinion is avoided." He quotes P.M. Peek, the African folklorist: "While we are enjoined to ‘get to the point,’ such quick and direct speech is often the sign of a poor speaker in Africa," adding that traditionally, "going round for long in parables" is a shrewd strategy for brokering disputes between villagers. The longer you can make people sit with each other and talk things over, the more likely it is that cooler heads will prevail. Blake also quotes the ethnographer Elinor Keenan who wrote of the Malagasy: "Most villagers can tell you that one who speaks well manolana teny (twists words). In kabary [formal style], a good speechmaker miolaka (winds in and out). The meaning of the utterance becomes clear gradually as the speaker alludes to the intent in a number of ways."

One needn’t subscribe to a Kabbalistic view of language to understand that its powers are not entirely governable by reason. Yet we persist in squeezing the life from it in pursuit of that elusive grail, direct communication—relegating anything extraneous to the margins of "ludic play" or "poetry." (Even poetry these days is supposed to be economical to the point of erasure.) Secret Language is a primer on how various and unstable communication can be. And it reminds us that the rehearsal of that moment when concealing becomes revealing is a powerful resource—one might even reserve the word divine for it.