THE DEMOCRATIC PARTY, which hasn't had an original thought in years, claims to be in the marketplace again, shopping for ideas. Despite some skepticism, I will take the Democrats at their word and offer them a free idea, an issue so broad and potent that its future is certain in American politics.

Here is how one politician frames it:

"I am calling . . . for an end to giantism, for a return to the human scale -- the scale that human beings can understand and cope with . . ."

"Human scale" as a political issue? I can already hear the neoconservatives groaning, the Moynihans and Jacksons and Wattenbergs who would like to drive the ecofreak "small is beautiful" rhetoric out of the Democratice temple. Leave that garbage to Ralph Nader or the spacey governor named Jerry.

Perhaps I should add this fact: This attack on "giantism" came from Ronald Reagan, circa 1975.

Now here is another expression of the same theme:

"Large enterprises inevitably collapse of their own weight, because they are disproportionate to the human beings who have to run them. Cellular structures will respond to disturbances with resilience, but large crystalline structures will not. Punch plastic and it bends. Punch crystal and it shatters."

That text might well have been taken from the sermons of the late E.F. Schumacher, who articulated the credo about the virtues of smallness and the badness of bigness. As it happens, I am quoting John McClaughry, a free-wheeling right-winger who at this moment works in the White House. He is a senior policy adviser on President Reagan's Domestic Policy Council, assigned to staff the cabinet council on agriculture, among other things.

Is McClaughry right about the inherent weaknesses of bigness? For that matter, was E.F. Schumacher? The romantic pessimist in me agrees that there are many Chryslers waiting to crash; but the optimist insists that large organizations can be made to function humanely, as readily as small ones.

In any case, we need to sort out the political confusion over who owns this idea. The short answer is that nobody owns it -- not Republicans, not Democrats, not liberals, not conservatives. The idea of reestablishing "human scale" in American institutions, whether in government or private business, is up for grabs. Only the political party which organizes support for that goal and acts effectively in pursuit of it will be able to carry the banner. Speech-making, whether by Ronald Reagan or Jerry Brown, is not sufficient to persuade.

In American politics, the realm of ideas looks more like concentric circles than the simple left-and-right seesaw of popular usage. The center circle, though it usually holds power, is the least interesting and original. It pragmatically steals ideas wherever it finds something that seems to sell. Just beyond the center, the quality of thinking improves modestly. Conventional conservatives, for instance, believe that bigness in government is the problem. Solution: Hack back the size of government. Conventional liberals, likewise, see the problem as bigness in business. Solution: Curb corporate power.

One has to move futher out in the concentric circles, to the left fringe and right fringe, in order to find free thinkers like McClaughry who are willing to condemn the scale of organization in both business and government. They see the enemy as "creeping giantism" in all realms of American life. Industrialized farming which squeezes out small and moderate-sized farms. Government bureaucracy which rewards giant enterprises in the name of efficient management and tramples individuals. Large school organizations which ignore diverse viewpoints on religion and morality. Vast corporations which, in the name of production, create dehumanizing workplaces where individual initiative and satisfaction are stifled.

Thus, on the outer circles, the libertarian right converges with the anarchist left on many points. They share the same perceptions, the same talismanic words, if not the same solutions. "Community control." "Appropriate technology." "Liberty." "Human scale."

Liberal Democrats, who thought bigness was their issue, have trouble grasping that "human scale" is an important, if secondary, strand in Reaganism. It is well represented by libertarians like McClaughry, who may not be the heavyweight policy brokers of the Reagan administration but who speak for a genuine element of the president's own beliefs.

Listen to radio commentator Reagan in 1976:

"All across the United States people have told me that the things they fear most are Big Government, Big Business and Big Labor. Bigness robs the average citizen of his rightful voice. The Big Government official ignores the average voter; the Big Business executive ignores the average stockholder; the Big Labor leader ignores the average union member. Often these three powers play their own political games, for high and important stakes, as if the rest of us did not exist."

Only now Reagan is president and already learning, as Democrats have before him, that translating a popular sentiment into effective government policy is the hard part. Ronald Reagan did not run against Bigness in 1980; that kind of talk scares many people and it was not a central theme of his campaign. moreover, like Democratic presidents before him, Reagan is now surrounded by powerful constituencies, from agriculture to automobiles, who are not exactly the archetypical "little guys" or political rhetoric. In part, the Reagan presidency should be judged by how genuinely he pursues the idea of "human scale" when the necessary policy changes will offend his important friends.

In the meantime, he deserves credit for pulling into government people like McClaughry who have the wit and nerve to think challenging thoughts about the status quo. McClaughry, I should add, has been on the conservative scene for many years, espousing volunteerism and less government. He ran the Institute for Liberty and Community in Concord, Vt., before joining the Reagan campaign and now lives in a rented log cabin in McLean. In the libertarian spirit of self-reliance, he would like to bring down his hog from Vermont. I advised him that, in Fairfax County, he would probably be arrested for keeping a hog in his backyard. In McLean, raising hogs might even by a felony.

The central question, as McClaughry puts it, is: "Do federal programs reward giantism? Is there a bias toward large enterprises, large institutions, large bureaucracies? The obvious answer is yes."

To invoke a simple example, McClaughry thinks of a federal department like transportation or energy which hands out grants to private firms to develop new technologies, alternative ideas for energy production or auto design or whatever.

"Suppose you've got $50 million to develop appropriate technology," McClaughry supposes, without conceding that the federal government ought to do this sort of thing at all. "If you give out 10 grants of $5 million each, it will go to biggies like Grumman and General Motors and TRW. But suppose you decide to give 50 grants of $1 million each.Then you're getting down to little guys like Uncle Jack's Anaerobic Digester Co. in Creston, Iowa.

"If you're a grants administrator, would you rather administer 50 grants to 50 little guys who have uncertain credit records, who are scattered all over God's green earth, some of whom will fight with their wives and run off to Canada in the middle of the grant? You don't have to be a Marxist to see that this is the triumph of concentrated capitalism. It's just common sense for the administrator who doesn't want to be called before an appropriations subcommittee and questioned about bad grants.

"So you go the safe route. There's no incentive in the bureaucracy to take risks. There's no malice in that statement, no ideology. It's just the natural consequences of large organizations."

McClaughry can imagine a world which encourages smaller orgainzations to flourish and which imposes new operating standards on large bureaucracies, rules which introduce "human scale" values. What are those human values? Personal responsibility. Common sense. Compassionate regard. Incentiveness. Risk taking.

Can a government agency, for instance, foster an entrpreneurial spirit? McClaughry would create a competition among hustling businessmen, give each a pile of dough and send them off to find those bright inventors with workable ideas. The winner gets rewarded generously; the losers get certificates of appreciation and are sent on their way.

"The objection will be made that some of these guys will be frittering away the money," McClaughry said. "Yes. They will. But I think that's the risk you take. I'm willing to bet the results will be better than if you give the money to large organizations."

Cynics with long memories will recall that this approach has been tried in government, notably by McClaughry's old boss, George Romney, when he was secretary of housing and urban development. The competition for new ideas in housing technology produced a lot of headlines, consumed a lot of federal money but is not otherwise remembered as a triumph.

In any case, the Reagan administration's attention to questions of human scale seems crude and uneven thus far. In the interest of saving money, shrinking the government, the Reagan budget take a few swipes at the federal bias toward bigness, such as the gross subsidies for super farms. But it also turns around and wipes out other programs like the National Co-operative Bank which foster alternatives. Reaganism preaches a doctrine of moving government decisions closer to the people, in city hall and the local school board, but it avoids the hard questions of corporate accountability, not to mention the inner dynamics of how huge business organizations make decisions and stimulate invention.

How would the Democrats get ahold of this issue? They might begin by acknowledging that it permeates nearly every other issue of public policy, that it is not a freaky sentiment of despised lefties but a major concern of our times, one which astute Republicans understood long ago.

So did astute Democrats. Sidney Harman, former under secretary of Commerce in the Carter administration, campaigned effectively for worker rights, arguing that reorganizing the rules of America's factories and offices would not only produce happier workers but better productivity and invention. Agriculture Secretary Bob Bergland left an important legacy in his landmark study of the structure of agriculture (a subject I will return to in the future) which documented the government bias toward bigness and proposed dramatic remedies.

But Republicans, being Republicans, are not likely to embrace those Democratic solutions and that is where the Democrats can start the argument. Who will speak for small- and medium-sized farmers? Who will put a premium on enterprises which are run by a handful of people with good ideas and lots of nerve? Who will find a way to instill common sense into large, remote bureaucracies?

If the Democrats wade into these questions, they will find conservatives like John McClaughry waiting for them and I expect that, given his manner, McClaughry will say: welcome.