Here is a Zen question for the traveler: Are you making your way toward your destination, or is it making its way to you? Anyone who has ever seen J.M.W. Turner's painting "Sunrise With Sea Monsters" will instantly recognize that question as the one the masterpiece poses: An amorphous head looms on the horizon, its mouth like a maw, drawing the viewer in. Curious, you step closer to the canvas; you feel at once as if the beast is hurtling toward you, and you toward the beast. It's impossible to tell which way the vector is pulling, but you know that you must close the distance -- be one with the unknown, go.

Call it an urge to travel.

Few have mastered the art of travel writing as well as Paul Theroux. Leading a reader to a new land while keeping him on the rim, observant, is devilishly hard to do. John Ruskin did it in Venice. V.S. Naipaul did it in the Caribbean. Bruce Chatwin did it in Patagonia. Jonathan Raban has done it in North America. And Paul Theroux has done it in the Middle East, Africa, China, South America, tirelessly, for an extraordinary 40 years.

The reason I love Theroux's Sunrise with Seamonsters: Travels and Discoveries, 1964-1984 is that it is a book in which you see the writer mid-course, minding the sails, struggling against the current. Theroux has written more elegant works -- more puzzled through and finely wrought: He himself questioned my choice when he learned about it. "Why have you picked that one?" he asked. "I've written far better." Precisely. I like it because it is exactly halfway -- 20 years -- into his journey. You can see the larger works in the making: The Great Railway Bazaar, his first travel chronicle, published in the '70s; The Mosquito Coast, about the madcap genius who takes his family to live in the wilds of Honduras; The Old Patagonian Express, in which Theroux travels from ice-locked Massachusetts to a desolate plateau in Argentina; Riding the Iron Rooster, which chronicles his train ride through China; Sir Vidia's Shadow, in which he takes on his feisty mentor; and Dark Star Safari, his moving return to Africa.

In Sunrise with Seamonsters, Theroux flexes his muscles for all the rest. He writes about his 20th high school reunion in Medford, Mass., as if he were adrift in a foreign country; he writes about Kipling's quibbles with America; he writes about Malawi as a callow 24-year-old during the Vietnam War -- serving as a teacher in the Peace Corps. He writes about sailing into mean waters just off Vineyard Haven, being drawn into the maw of the seamonster, not realizing it was there. There is much else on these pages, but the book reveals the heart of a writer: plying his trade, honing his abilities.

As you read, keep in mind that a collection of essays is much like a sketchpad. You will see images, attitudes and personalities here that emerge later in full living color. Compare his piece "The Orient Express," for instance, to the sharp critic that noses through China in Riding the Iron Rooster; or contrast his drugged-out travel buddies in "Memories of Old Afghanistan" to the very old soul who travels Africa in Dark Star Safari; read his essays on V.S. Pritchett or Rudyard Kipling or Henry Miller with an eye to the controversial mud-slinging contest he eventually engaged in with V.S. Naipaul in Sir Vidia's Shadow. And when you're through with all that, go read Theroux's The Stranger at the Palazzo D'Oro, his most recent publication, a truly dazzling selection of stories.

Join me online to discuss Sunrise with Seamonsters at 3 p.m. on Thursday, Sept. 30. Or wend your way to before that and post your questions in advance. If you are lucky enough to hold a ticket to Paul Theroux's presentation to our Book Club members on Tuesday, Sept. 14 (the event is now sold out), come prepared to discuss more than 40 books by this amazingly prolific writer. It's bound to be a fascinating journey. *

Marie Arana is the editor of Book World.