One hundred and fifty years ago Henry David Thoreau published Walden; Or, Life in the Woods, a textured account of his now fabled 26-month bivouac beside Walden Pond outside his native village of Concord, Mass. The book, however, was far from an immediate best seller. In fact, it took five years to sell the 2,000 copies initially printed by the publisher, and Walden slipped out of print in 1859.

Yet three years later, soon after Thoreau's death from tuberculosis, the publisher reprinted the book, and it has since become an American classic, translated into dozens of languages and often assigned as required reading in schools and colleges. Thoreau spoke for many readers of Walden when he observed that "many a man has dated a new era in his life from the reading of a book."

Walden is a peculiar masterpiece in that its author was not an appealing figure -- in person or in print. Born in Concord in 1817, the son of a pencil maker, Henry David Thoreau was a slight, wiry man with a droopy nose, rebellious spirit, tart personality and keen mind. He was a prickly character who wrote with passionate conviction and bruising candor.

Walden is punctuated by his cocksure pronouncements and eccentric conceits. Thoreau scolds and preaches, calling his readers and neighbors drones, dunces, robots and slaves. His irreverent outlook harbored no doubts; he took great pride in his superior system of values - and his contrariness.

As he declared, "The greater part of what my neighbors call good I believe in my soul to be bad." When he compared himself to other men, he wrote, "it seems as if I were more favored by the gods than they."

Thoreau relished the solitude of his rough-hewn lakeside cabin because he was so sure of the value and virtue of rustic simplicity and deliberative living. "I should not talk so much about myself," he explained, "if there were anybody else whom I knew so well." He often displayed more contempt than compassion for the "mass of men (who) lead lives of quiet desperation." Most people, he declared, "live meanly, like ants."

Yet for all of his crabby and cranky bravado, Thoreau was a sincere reformer uncorrupted by materialism. "I brag for humanity," the Harvard graduate wrote in Walden. He once confessed his weakness for using exaggerated language. "You must," he said, "speak loudly to those who will not listen."

For all of his trumpeted solitariness, he harbored a deep desire for communication and community. He wanted to awaken and excite people to the wonders of their natural surroundings. "We can never have enough of Nature," he proclaimed.

Walden also endures because it sings with originality. It is stippled with striking observations, provocative insights and pungent prose. Perhaps it was Thoreau's solitary nature that made him so scrupulously observant -- he had a falcon's eye for detail and took a scientist's delight in the operations and wonders of nature.

His sinewy descriptions of his natural surroundings and rustic routine (hoeing beans, chopping wood, catching fish, reading, writing and sauntering the countryside) are alluring. He often would sit in the dooryard of his cozy cabin "from sunrise till noon, rapt in a revery, amidst the pines and hickories and sumachs, in undisturbed solitude and stillness, while the birds sang around or flitted noiseless through the house."

His dramatic effort at Walden Pond to practice plain living and high thinking still resonates with people of every country and every era. "I went to the woods," he explained, "because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived."

What has most captivated readers of Walden is its recurring emphasis on fundamentals: how much is enough? what really matters? "Simplify, simplify," Walden repeatedly urges us.

Thoreau did not expect readers to abandon their labors and go live in the woods, but he did encourage people to slow down and take time to reflect on who they are, how they live and what they value. Such an ideal of self-aware self-reliance buoyed by the "tonic of wilderness" is as seductive as it is elusive.

We all can afford to free ourselves from the lure of conformity and the corruption of materialism. And we all wish -- in theory at least -- to lead more reflective and deliberate lives. But it is devilishly hard to say no to the barrage of enticing activities and seductive desires that complicate our lives and derail our best intentions.

"Tis a gift to be simple," says the Shaker hymn, and it indeed requires a special gift of fortitude and imagination to sustain a regimen of enlightened restraint. Thoreau appreciated the challenges and difficulties of transcendental simplicity, but he closed Walden with words of timeless reassurance: "I learned this, at least, by my experiment; that if one advances confidently in the direction of his dreams, and endeavors to live the life which he has imagined, he will meet with a success unexpected in common hours."

Simplify, simplify.