Umberto Eco writes somewhere that a sign may be defined as anything that can be used to tell a lie. This remark sounds cynical. But it’s really just the most extreme formulation of something implied by events in the Garden of Eden.

As you may recall, God gives Adam the power of speech and tells him to name “every living creature.” And so Adam does – not excluding the creature he calls “Woman.” But the next time we find Adam using language in Genesis, it is not exactly for its denotative properties. Having palpably annoyed the Almighty, he blames everything on the woman, hoping thereby to avoid the consequences of his own actions. (Like that’s going to work.)

Leaving aside the gender studies implication, this is interesting as a fable about communication itself. The power to symbolize gives rise, in very short order, to the ability to conceal.

Such was not really the point of the story, as I recall it from Sunday school anyway, but it came to mind while reading Barry J. Blake’s Secret Language: Codes, Tricks, Spies, Thieves, and Witchcraft, just published by Oxford University Press. The subtitle is both accurate and cryptic, and provides only a hint of just how intriguing and diverting a book this is. I suppose you could read it straight through, but Secret Language feels much more like a volume for dipping into when the mood strikes or the time permits. The author is an emeritus professor of linguistics at La Trobe University in Australia; and his book qualifies as a learned miscellany, rather than a monograph.

Blake catalogs a variety of techniques used to conceal or disguise meaning; or to limit its circulation, or to draw out the hidden powers of language itself. They include cryptography, Kabbalah, crossword puzzles, riddles, anagrams, magic spells, slang, and the private languages that emerge within tightly knit groups.

Part of the fascination of the book comes from noticing how often these modes of concealment resemble one another, or bleed together.

The ability to store information by writing it down (in effect, concealing it from the eyes of the illiterate) was once rare enough to make it a close kin of sorcery. And so the properties of the written word were themselves virtually occultic. The power of an amulet might come from a tiny scroll inside, running it like a little Pentium processor; and the text on that scroll could be baffling unless you knew to look for the anagram spelled out by the first letter in each word.

Or words might be written backwards – whether to conceal their meaning or to reverse their magical properties. Reversal of words could also have more purely commercial application, in the case of “back slang,” used among food vendors in London since the early 19th century. “It is essentially a system of enciphering words,” Blake explains,” by taking the written forms and pronouncing them backwards.” Thus “fish” becomes “shif,” “old” turns into “delo,” and “no good” is “on dog.” So a couple of merchants could talk candidly (“The shif is delo and on dog”) without customers being any the wiser.

Any given occupation will tend to generate its own jargon, mostly for the sake of convenience rather than to keep outsiders in the dark. But in some cases, a self-consciously “professionalized” diction amounts to a form of concealment – if only of total vacuity.

Baker gives a fine example of almost meaning-free writing from a memo by a school administrator: “Care is taken to avoid creating new categories of high staff turnover schools in regional areas not within defined categories of remoteness in determination of hard-to-staff schools developed under the total recruitment strategy.”

Well, one would hope.

Secret Language is dense with examples and generous with explanations, but light on general ideas (philosophical, sociological, or otherwise) designed to subsume the varieties of linguistic concealment.

That’s OK. There are theoretical works aplenty meditating on Power and Language and the Secret. It is good to have a book that gives you something to ponder without being ponderous itself. And it can be recommended in particular to anyone disposed to find language itself, as such, a source of pleasure.

The author quotes a fairly conservative British lexicographer, H.W. Fowler, who in the 1920s offered a surprising defense of slang. At one level, a piece of slang is like any other variety of “secret language”: it keeps access to meaning restricted to initiates. But it is also – again, like any other form of discursive concealment – an expression of inventiveness. It is, in Fowler’s words, “the diction that results from the favorite game among the young and lively of playing with words and renaming things and actions; some invent new words, or mutilate or misapply the old, for the pleasure of novelty, and others catch up on such words for the pleasure of being in fashion.”

Or to put it a different way, it is evidence that we’re never quite done naming the world.