IN the pecking order of 19th-century Concord, Mass., there was no question of whether Emerson or Thoreau was the more important figure. Emerson had been a minister, the son of a minister, and the grandson of one. As a lecturer he traveled the nation speaking in public and being generally well received. His books won him a wide, if selective, audience. He was cooperative and convivial with the prominent members of the town. In fact, he was one of them. He lived in a large, comfortable house in a central location, and while his radical views were frowned on by many, he was always a respected citizen. Thoreau, on the other hand, was much younger and from a much less successful family. His father had numerous jobs before settling on pencilmaking as a livelihood, and his mother ran a well-known boarding house. Thoreau himself had lived at various times in the Emerson household as a handyman and prot of the elder writer. He was well-known to be crotchety and acerbic. His literary career had not gone far. He even taught boys how to fly kites during working hours. And he had wheeled wood in a wheelbarrow d own the street on the Sabbath. He could be counted on to be extreme, even outrageous, to the average busy and buttoned-up New Englander. Things have changed. Emerson is still respected. His white house is still preserved and may be visited. People praise him, and his essays and poems are still taught in universities. His thought is important in American philosophical history. His work still invites scholarly articles and books, and pithy and incisive Emersonian statements are still invoked. But it is all a little cool, a breeze off a frozen lake, a man in marble. Thoreau, on the other hand, is read and studied with more enthusiasm - and not only by scholars. He invokes more controversy now than ever, and he is condemned and praised in arguments over modern environmentalism, modern failures to support unlimited business enterprise, and modern attitudes toward success. There are many reasons for this. One is that Emerson was a generalist who tended to abstract things and wrote about foxes, flowers, his neighbors, the local indigents, bluebirds, gardening and farming, picking huckleberries, and fishing - and in the middle of this witty and often humorous commentary said unforgettable things about how life should be lived. He can be read also just for the huckleberries. Thoreau, on the other hand, engages basic attitudes at the same time that he tells jokes and regales t he reader with stories about places he camped and people he met. Emerson wrote extremely well, but Thoreau handles prose the way a master swordsman does his foil, thrusting and parrying with grace and force - or sometimes the way Michael Jordan does a basketball, soaring and slam-dunking his opinions with total authority. THERE are also other reasons Thoreau has overtaken Emerson in the popular mind, not the least of which is the Thoreau Society, which recently celebrated its 50th anniversary. When it first met, in the usual steamy weather of July in Concord, it numbered only a handful. At that first meeting, the society elected a young scholar, Walter Harding, as its secretary. Professor Harding retired this year after holding that post for 50 years, longer than Thoreau himself lived. It would be hard to imagine a small organization more fortunate in selecting its key figure. Harding kept the early records of the society, edited its quarterly newsletter for his entire tenure, and balanced the interests of the Concordian members with those increasingly far-flung. He formed and maintained a long series of friendships, nurtured the society, and found new opportunities for scholarly study of Thoreau, including his own summer seminars held in Concord, which he supervised for many years. He has maintained a running bibliography of publications on Thoreau from the significant to the most minuscule. He has also frequently published on Thoreau, including a major biography, much basic scholarly work, and editions of Thoreau-related material. But he was not a mere writing machine. His charm and boyish smile, his fund of humorous stories about things Concordian, and his openness have kept the organization from being inundated by dry-as-dust scholars. Enthusiasts, amateurs, and the curious also find a ready home in the Thoreau Society. Harding loves to recount the story of one member from New York who regularly notified the Concord police of his desire to sleep on the porch of the local public school when he came to town for the annual meeting. At his passing, he left his entire legacy to the Society. This consisted of a small number of copies of a slim book he had written entitled, "Why Work?" Twenty-five years ago, inspired by the fact that the other major Concord authors - Emerson, Alcott, and Hawthorne - had houses people could visit, but Thoreau had none, an indefatigable Concordian, Mary Sherwood, founded the Thoreau Lyceum, finding the means to buy a house as a Thoreau headquarters. The curator of the Lyceum was Anne McGrath, a woman who had picked up her lifelong interest in Thoreau from her father. She and her able staff created a strong educational center in the Lyceum, encouraging vi siting school groups and others to investigate the life and work of the Concord naturalist and social critic. Verve and activity characterize the Thoreau Lyceum far more than the more museum-like homes of the other Concord authors. As would seem inevitable, the Lyceum and the Thoreau Society merged. After all, many of the same people belonged to both. And this summer the joint organization put on a Thoreau Jubilee, expanding their usual annual meeting to a series of meetings that took the best part of two weeks in Concord and the city of Worcester. Amazing. What other American author has provoked such a celebration? And who would have thought that Thoreau, who would cut across back lots to avoid the publicity of the main road, woul d invoke such enthusiasm? He always was different. And a little extreme. And very endearing. And very fortunate in his friends - beginning with Emerson.