Who among us has not imagined, down to the tiniest detail, what we would do with our lives if some fantasy benefactor suddenly freed us from the drudgery of earning our daily bread?

William Drayton Jr., that's who.

Which leaves Drayton with some heavy imagining to do. Yesterday he was told there will be a $40,000 tax-free check in the mail for each of the next five years, and he can do anything he wants with it.

Bill Drayton, Washington lawyer, public servant, amateur philosopher and peripatetic reformer, was one of 25 American superachievers, ages 33 to 78, chosen yesterday by the MacArthur Foundation to receive from $176,000 to $300,000 over the next five years to "follow their own creative bent."

Also among the awardees -- from a range of fields in science and the arts -- is Roger Payne, 49, a research scientist for the World Wildlife Fund in Washington. Payne, who received a $240,000, five-year grant, spends most of his time in the organization's whale research laboratory in Lincoln, Mass.

Said Drayton yesterday, "This is all a rather abrupt surprise.This was quite out of the blue. I've got more contemplating to do."

For the last three years, the soft-spoken Drayton, 41, has been best known in Washington as a needle-sharp thorn in the side of the Environmental Protection Agency. Drayton served as the agency's policy chief in the Carter administration, and he became convinced shortly after the Reagan administration took office that its intent was to demolish the agency.

In 1981, he formed a group called "Save EPA" and sallied forth to do battle against the budget-cutters. He came armed with volumes of budget analysis, charts and graphs, haunted Hill hearings and quickly earned a spot on the Rolodex of every environmental reporter in town.

The agency's political appointees called him "The Slasher." Drayton, a slight man whose voice has the hard edge of a marshmallow, seemed to find it amusing.

Needless to say, the news of Drayton's good fortune didn't bring a rousing chorus of cheers at the EPA. "What's he going to use it for? More broadsides against the agency," grumbled one high-ranking official.

Maybe. Maybe not.

Drayton's real interests these days revolve around two other pet projects: the Ashoka Society, a fellowship program for Third-World innovators, and Next Steps, a nonprofit organization that acts as a sort of matchmaker between the nation's creative thinkers and the guest-hungry television talk shows.

"They are my top priority," said Drayton, who helped found both organizations. "I would have been very happy not to be doing the environmental stuff. I saw it more as a responsibility."

The Ashoka Society and Next Steps are the logical extensions of an eclectic public-service career that began in New England and spilled into the Far East more than 20 years ago.

Drayton, who describes himself as "a public-service entrepreneur," was reared in New York and New England and educated at Harvard, Oxford University and the Yale Law School. After a stint in the employ of then-Sen. Hubert H. Humphrey (working on civil rights issues), he joined McKinsey & Co., an international management consultant firm, where he still works part time as a lawyer.

Among his first projects was an innovative cigarette tax for New York. The so-called "tar-nicotine" tax was adjusted upward according to the tar content of the cigarette. It was, according to Drayton, the impetus for the shift to low-tar cigarettes.

"I spent four years fighting the tobacco companies' ultimately successful effort to repeal it," he says. "But by then we had achieved what we wanted. They channeled their advertising into low-tar cigarettes. The public got cigarettes that were safer -- well, less unsafe."

After teaching stints at the Stanford Law School and the Kennedy School of Government and Public Policy at Harvard, Drayton went to the EPA at the request of Carter administration officials who were impressed with clean-air enforcement strategies he had designed for Connecticut.

When he left the EPA, he says, "My plans were to get the Ashoka Society up and running, and I had in mind a project on economic policy alternatives. But when things went to a radical extreme at the EPA, I had to act as watchdog."

But if the MacArthur money will make life a little easier for his public-interest projects ("They're like a little crew of ducklings with their mouths wide open," he says), it isn't likely to change Drayton's life much.

I've been trying to structure my life as much as possible to do that anyway," he says. "I'm a bachelor with simple tastes."

The New York-born Payne got the news when he returned from an errand and got a message to call the Foundation. "I was elated -- cubed," he says.

"It's tax free. One does not have to contribute to inflated military budgets," says Payne.

Payne, who received the award chiefly for his work in cetology, the study of whales, and whale conservation, was instrumental in the discovery that humpback whales create "songs," with rules similar to human musical composition. His "Songs of the Humpback Whale," a long-playing record of the mammals in song, sold more than 100,000 copies in 1970, according to Payne. Payne also helped create Golfo San Jose' in 1974, a whale preserve at Peninsula Valdes, off the coast of Argentina, in 1974.

"I feel I'd like to do something that will really count . . . that will carry me out to the edges of possibility, something outrageous," Payne says of his windfall.

Payne bemoans the financial support given to conservation, saying, "Conservation is one of the poorest children.

"In order to change the world, we must raise the world to the importance of conservation. It's the difference between a world worth living and just trash."

Other recipients of the fellowships announced yesterday are:

Shelly Bernstein, 44, clinical fellow in pediatrics at Harvard Medical School, Cambridge, Mass., and researcher at the Massachusetts Institute of Technology. Bernstein, a molecular biologist working on the genetics of cancer, has also studied blood disorders among children: $176,000.

Peter Bickel, 44, divisional dean of physical sciences at the University of California at Berkeley, is a statistician working in the areas of robustness and adaptive inference: $220,000.

Sidney Drell, 58, deputy director of the Stanford Linear Accelerator Center, codirector of the Center for International Security and Arms Control, and professor at Stanford University. Active in environmental and policy issues, he has helped promote entrepreneurial skills in the Third World: $276,000.

Mitchell Feigenbaum, 39, professor of physics at Cornell University, has worked in the universal properties of nonlinear systems and created an analysis of chaos: $200,000.

Michael Freedman, 33, mathematics professor at the University of California at San Diego, solved one of topology's outstanding problems by proving the four-dimensional Poincare conjecture: $176,000.

Curtis Hames Sr., 64, a country doctor from Claxton, Ga., is affiliated with the University of North Carolina, the Medical College of Georgia and the Medical University of South Carolina. He works in epidemiological research: $297,600.

Shirley Brice Heath, 45, an associate professor of education at Stanford University who specializes in linguistics and anthropology, has studied black and white children in rural and suburban settings: $224,000.

Bette Howland, 47, a novelist based in Albuquerque, has published fiction chiefly set in Chicago, where she grew up. Her books include "W-3" (1974), "Blue in Chicago" (1978) and "Things to Come and Do" (1983): $232,000.

Bill Irwin, 34, New York mime artist and theatrical performer, combines vaudeville with contemporary theater. He is currently acting in the New York production of "Accidental Death of an Anarchist": $180,000.

Fritz John, 74, a retired mathematician, and professor emeritus with the Courant Institute, works in partial differential equations: $300,000.

Galway Kinnell, 57, poet, writer and translator, has published works which include "The Book of Nightmares" (1971) and "Mortal Acts, Mortal Words" (1980): $272,000.

Henry Kraus, 78, an art historian in Paris, has studied medieval church building and has helped to identify and preserve medieval church stalls in Spain: $300,000.

Peter Mathews, 33, an archeologist who studies Mesoamerica, is a research assistant at the Peabody Museum of Archaeology and Ethnology: $176,000.

Beaumont Newhall, 76, a photography historian, is an art professor at the University of New Mexico, Albuquerque: 300,000.

Edward Roberts, 45, a respiratory quadriplegic, is an advocate for the rights of the disabled and founded the World Institute on Disability: $224,000.

Elliott Sperling, 33, a scholar of medieval and modern Sino-Tibetan relations, is currently has a one-year teaching appointment at the University of Southern Mississippi: $176,000.

Frank J. Sulloway, 37, is a science historian at Harvard University's department of psychology and social relations and the author of "Freud, Biologist of the Mind: Beyond the Psychoanalytic Legend": $192,000.

Alar Toomre, 47, an astronomer, is also a professor with the department of mathematics at the Massachusetts Institute of Technology in Cambridge, Mass.: $232,000.

Amos Tversky, 47, a Stanford University psychology professor, has investigated the psychological factors that distort rational decision-making. He is currently a visiting professor at Hebrew University, Jerusalem: $232,000.

John Kirk Train Varnedoe, 38, art historian, is a professor at the New York University Institute of Fine Arts. He is codirector of "Primitivism in Twentieth Century Art: Affinity of the Tribal and the Modern," an exhibit at the Museum of Modern Art: $196,000.

Bret Wallach, 41, an essayist and geographer, is an associate professor at the University of Oklahoma: $208,000.

Arthur T. Winfree, 42, a mathematician, is professor of biological sciences at Purdue University: $212,000.

Billie Jean Young, 37, a community activist in Mississippi, heads the Southern Rural Women's Network, encouraging leadership skills among rural women: $192,000.