????From F.D.R. to Ayn Rand, an unusually entertaining ode to a fading art.

????By Daniel Okrent

????The novelist and critic Thomas Mallon began to explore the idea of a book about letter writing, he tells us, "when a first-class stamp cost 29￠."

????Just think of what has happened to letter writing since then: IMHO, you could LOL. Or weep.

????As Mallon doesn't need to tell us in Yours Ever: People and Their Letters (Pantheon), he's writing about a practice that for at least eight centuries was the primary means of communication between people who happened not to be in the same place at the same time.

????It was more than just communication, though; it was a form of human conduct enhanced, even exalted, by the demands it imposed on those who practiced it.

????He writes, "The small hardships of letter writing -- having to think a moment longer before completing utterance; remaining in suspense while awaiting reply; having one's urgent letters cross in the mail -- are the things that enrich it, emotionally and rhetorically."

????Mallon's stroll through letter-writing history, arranged by genre (Absence, Friendship, Complaint, Confession, etc.) and brightened by selective quotation from exemplary practitioners, is itself like good letter writing -- fluid, discursive, aphoristic.

????Graham Greene's correspondence reveals a man, writes Mallon, "relentlessly corrective and just as frequently wrong." Mark Twain's vivid, full-blooded letters provide "a moving picture instead of the typical collection of stills." On the cranky complaints of Thomas Jefferson, Mallon writes, "the citizen reading them today is disinclined to approach the man's table and pull up a chair."

????Most of the people whose letters Mallon explores are literary sorts (no surprise there -- most people you'll encounter in a poker game know how to play cards). But Mallon's erudition (which he wears lightly) and his curiosity (which he shares generously) have sent him diving into words left behind by royalists and revolutionaries, murderers and lovers, Ann Landers and Ayn Rand.

????He parses missives as ancient as those that Abélard wrote to Héloise, as recent as the Unabomber's, and as unlikely as the steaming love bombs that Woodrow Wilson -- strait-laced, upright, no-fun-at-all Woodrow Wilson -- sent from the White House to his second-wife-to-be.

????Presidents generally make good material for Mallon. Franklin Roosevelt's effusive correspondence, for instance, is littered with so many exclamation marks it would embarrass a sophomore at a girls' boarding school. It may be disconcerting to encounter a great leader writing to his ambassador to Italy to say, "Watch out for that tummy!" -- but having read it, I suspect I know F.D.R. more fully than I did before.

????That's true about most of the people you'll run into in this engaging book. Given the present and future of letter writing, it's a privilege to be cherished.