A phone interview isn't possible. Scott Nearing, 100 years old yesterday and living with his wife, Helen, in their self-built home overlooking Penobscot Bay in Harborside, Maine, has been in bed for several months. His health is slowly failing. At one century of age and an American Methuselah, Nearing has been a giant of leftist dissent since 1915 when he was fired from a professorship at the Wharton School of Finance for crusading in favor of child labor laws. Since then, Nearing, an intellectual of genial manner, has kept strict faith with the pacifism, socialism and vegetarianism he embraced as a young man.

Over the phone, Mrs. Nearing, who is 79 and the coauthor of the couple's enduring back-to-the-land classic, "Living the Good Life," explains why her husband, though at home, is unavailable. "Scott is dying. But it is no time for sadness. Now is the moment for his leaving the good life. He is going gently, without pain--the way he lived."

One hundred years have barely been enough for Scott Nearing. He wrote 50 books, including "The Making of a Radical: A Political Autobiography" in 1972, "Democracy Is Not Enough" (1945) and "War: Organized Destruction and Mass Murder by Civilized Nations" (1931). With a doctorate in economics, he taught for 10 years at Wharton. He ran for Congress against Fiorello La Guardia in 1918. In the 1920s, he and Clarence Darrow traveled the country staging public debates. By 1932, having acquired a national following for writing and lecturing about the causes of the Left that Norman Thomas and Eugene Debs had been advancing politically, Nearing decided he wanted more. It would be time to "part from Western civilization."

At 50, he became a homesteader in Vermont. He cleared fields and built his house and outbuildings with the stones he unearthed. From Vermont, Nearing saw that many on the Left back in the cities were forced to deliver newspapers or milk for their living. "I chose homesteading as a way of life under United States right-wing pressures in the 1930s . . . A homestead is a habitation in which a family group manages to eke out a living on its own. If one is to be poor, it is better to be poor in the country than in the city because one can at least grow one's own food instead of having to buy it from the barrows or pick it out of garbage cans on city streets."

The "competitive, acquisitive, predatory culture" Nearing thought he escaped in Vermont chased after him in the form of ski resorts and shopping malls. In 1952, at 70, he pushed further into the woods and into life by beginning again with a rockish tract on the Maine seacoast. Twenty years later, entering his 10th decade, he wrote that "our life in the country is not an ivory tower retreat. It is an instance and an example of sane living in an insane world. It is a means of contacting nature, in many ways as important as contacting society. It enables us to live harmlessly in a violent world."

Nonviolence, as expressed in the creed of pacifism, has been at the core of Nearing's thinking. He decided to have nothing to do with butchery, whether it was the organized kind in wars or in the complicity of killing animals for food. "The event which finally tore me away from my emotional and habitual commitment to Western civilization was the decision of Harry Truman to blot out the city of Hiroshima--it happened on my 62nd birthday, Aug. 6, 1945 . . . From that day to this I have refused to say 'my government' or 'our government' when referring to Washington . . . The decision was the death sentence of Western civilization."

Standing against the bombs and guns in World War I and World War II, Nearing belonged to the tiniest of dissenting minorities. In 1919, the administration of Woodrow Wilson prosecuted Nearing for writing an antiwar pamphlet, "The Great Madness." After a 13-day trial and 30 hours of jury deliberation, Nearing was acquitted. He suffered nevertheless. Macmillan, the publisher of his six books by then, said it would no longer do business with him. Now, as well as being a silenced teacher, he was a muzzled author. "War," he wrote, "is an attempt of one group to impose its will upon another by armed violence . . . But war has wider implications. War offers those in power a chance to rid themselves of opposition while covering up their designs with patriotic slogans."

The ridding of Nearing never happened. He found other publishers, other students. His books have been read, his ideas cherished and his ideals shared. For decades, thousands of visitors have been coming to his farm every year for conversation and inspiration. The other day, Mrs. Nearing said the visitors still come. Her husband asked that the gate be kept open.