Around 5 o’clock most afternoons, you’re apt to find me at home nursing a cocktail as I apply myself to a dozen or so lines of Greek from “The Iliad” or “The Odyssey.” Minus the tippling, this is a carryover from the two years of classical Greek taught at my Jesuit high school in St. Louis, where we covered sizable portions of both Homeric epics. I also took four years of Latin — Caesar, Cicero, Catullus and Virgil — but Greek left a deeper impression.

If construing Greek sounds like work, it’s really not. The hard part came decades ago, when my classmates and I memorized hundreds of vocabulary words and mastered the complex but orderly grammar. Also, the editions I use are generously annotated, and I’m not too proud to consult an English translation when I get stumped. For me, reading Greek is a pleasurable challenge, and the rewards . . . well, for those, let’s turn to Adam Nicolson, author of a stirring new book, “Why Homer Matters.”

Or, rather, let’s turn to Socrates, speaking in a passage quoted by Nicolson from Plato’s dialogue “Ion”: “The Muse first of all inspires men herself; and from these inspired persons a chain of other persons is suspended, who take the inspiration.”

By extension, readers of Homer today, whether in the original or in translation, join a chain of inspiration that goes back to about 700 B.C., when the Homeric poems — already existing as oral extravaganzas — are thought to have been set down. In a way, though, the chain stretches even farther, to the period when the events depicted in the epics may have taken place, some perhaps as early as 1800 B.C. So, reading Homer today admits you to a club that spans the history of Western culture. And if you’re fanciful, you can imagine the club’s president as being none other than the Muse herself, whose first and arguably finest protege was Homer.

But was there such a person? Or two? Or more? Nicolson explores these questions at some length. An influential American scholar named Milman Parry sought out 20th-century Yugoslavian bards and, based on their performances, speculated as to how the rhapsodes (their ancient Greek counterparts) may have operated: bringing a core story to life by adding such details as came to mind and sprinkling in stock phrases (in Homer’s case, “rosy-fingered dawn,” “wine-dark sea,” etc.) to produce what Nicolson calls a “composition-in-performance.” Thus, what was heard by one audience might differ markedly from what was heard by the next.

That sounds right, especially when you consider the daunting challenge of memorizing and reciting works as long as the Homeric epics. But Celtic scholars dissented, citing, among other things, the work of a stonemason and storyteller named Duncan Macdonald: In 1953, he recited an hour-long tale almost word for word as he’d delivered it three years earlier. Similar feats of memory have come to light elsewhere, and why couldn’t the rhapsodes, living in an oral culture with a minuscule literacy rate, have matched or bettered such a degree of “curatorial exactness”? In other words, “The Iliad” and “Odyssey” that have come down to us may not be quasi-arbitrary versions dictated by performers with a license to improvise. We may have each poem in a one-and-only form, as reliable as holy writ. (It may be no accident that the subject of an earlier book by Nicolson is the making of the King James Bible.)

In any case, linguistic analysis suggests that each epic had its own author — its own Homer, if you will — working 30 to 40 years apart, with “The Iliad” coming first. As Stephen Mitchell notes in the introduction to his recent translation of “The Odyssey,” “It is remarkable that two geniuses flourished so close to each other in time, but no more remarkable than Aeschylus and Sophocles, Mozart and Beethoven, or Matisse and Picasso.”

To get a fix on the origins of the Greeks themselves, Nicolson traveled to what is now Ukraine. Citing numerous clues in the poetry and resemblances between tumuli (burial mounds) found on the Central Asian steppes and in Greece, he argues that the Greeks’ ancestors were grassland pastoralists and horse-taming raiders who migrated south. Around 1800 B.C., he says, “high-speed chariots, high-speed sailing ships and a warrior culture from the north all come together in the Aegean at the same moment. . . . This newly energized world is the meeting of cultures that Homer records.”

Speaking of that warrior culture, Nicolson reminds us that the two epic heroes have divergent views of war. Achilles sees it as “the source of human tragedy, Odysseus as the opportunity for self-advancement. And beyond them both stands Homer, the great voice of understanding . . . refusing to decide.”

Nicolson might have done more to evoke the spell cast by the poetry itself: for example, the brio of its dactylic hexameter (in his essay “On Translating Homer,” Matthew Arnold calls Homer “eminently rapid”). But Nicolson eloquently sums up what we still look for in Homer: “wisdom, his fearless encounter with the dreadful, his love of love and hatred of death, the sheer scale of his embrace, his energy and brightness, his resistance to nostalgia.”

By the way, I’ve checked, and my high school still offers classical Greek.

Drabelle is a contributing editor of Book World.