Democratic Gov. Edmund G. (Jerry) Brown Jr. of California yesterday offered himself for the second time as an anti-establishment contender for the presidency.

Sounding more like an old-fashioned American patriot than the spacey mystic of his popular reputation, he called for a return to old values of "productivity," "investment instead of borrowing and spending" and "national independence from foreign whim."

His most dramatic, though not unexpected, proposal was for a national energy corporation to "develop and manage our own oil on public lands." He would prohibit the importing of foreign oil except through the federal government, he said, and would seek presidential authority to appoint public representatives to the multi-national oil companies to "represent the people, not just the shareholders."

Brown, 41, launched his shoestring, underdog campaign at the National Press Club in Washington "where the problems are and also some of the solutions." A poster on the podium read "Wow! Brown Now." Then he took his entourage into New England and, as if courting comparison, made his first stop a refurbished Boston shopping center in the shadow of Faneuil Hall where Sen. Edward M. Kennedy (D-Mass.) declared his candidacy the day before.

He told Bostonians that Washington is "literally glutted in money." They are raising salaries for themselves while they run the printing presses and ruin the dollar for everybody else, he said.

He accused the nation and its leaders of "a collective failure to grasp a new age." He held himself out as a clear alternative to the "dying myths" of the Democratic Party.

"The language of politics is debased today.Not unlike our currency, it inspires more cynicism than trust," he said.

Stressing "stewardship, not exploitation," and "quality instead of quantity," Brown repeated his battered proposal to balance the federal budget.

He said he would "jawbone" to make U.S. tax policies more selective. Under the Carter administration, he said, people get the same tax credit for investing in a slot machine in Las Vegas, or in an old people's home, for building a solar home or a gas-guzzling car.

His three-point program as he summed it up is: "To protect the earth, serve the people, explore the universe."

He also repeated his opposition to higher defense spending and nuclear power.

Running an improvished campaign from the cellar in the Democratic standings, Brown conceded that he cannot win unless there is a "paradigm shift in the political chemistry of the Democratic Party."

Whether or not that occurs, political pundits are looking to Brown's well-tuned political antennae to help define the issues for the top contenders. wThey are also watching to see from which of the others he might draw off support.

Brown dealt philosophically with questions about his image as a flake. If President Carter's problem is "incompetence," and Kennedy's is Chappaquiddick, wasn't Brown's problem his image as a "cloud nine" candidate, a reporter asked yesterday.

"If I had to choose," Brown said, "I'd take the latter."

A political brat, son of a former California governor, Brown had the curiosity value of a Martian when he dropped into the national political scene four years ago, speaking of "an era of limits," and the politics of less. sHe made a splash in that presidential race, but was too late to do real damage to frontrunner Jimmy Carter.

Since then, however, he has become a media cliche, certified in the Doonesbury comic strip.

When not dismissed as a flake, he has often been accused of cynical opportunism, as when he flip-flopped on California's Proposition 13. He opposed it until it passed and then jumped on the badwagon.

His record as governor is mixed. On the plus side is an unprecedented farm labor law passed early in his administration, and, after Proposition 13, reduced state taxes.

But his campaign excursions out of state and his embrace of antinuclear activists such as Jane Fonda got him into a fight this year with his state legislature, which shelved several of his proposals and overrode four of his vetoes.

And among his recent appointees, one has admitted to making obscene phone calls and another is awaiting trial on charges of growing marijuana.

Brown has also been criticized for his travels with rock queen Linda Ronstadt. He has refused to discuss their relationship.

In Kennedy country yesterday, Brown drew a respectable crowd, estimated at about 800, mostly students, especially the antinuclear contingent. Most of them seemed bemused and intrigued, with the political spectacle itself as much as by Brown.

Brown hopes to establish his credibility as a candidate by coming in second, after Kennedy, in the New England primaries, aides said.

He is depending heavily on volunteers from the antinuclear Clamshell Alliance to do his nuts-and-bolts field work there.

The candidate dismissed the flurry of early polls and straw votes, all of which point to his early demise as a viable contender, as "tea leaves."

He called the recent straw vote in Florida, which Carter won, "just another metaphor for the bankruptcy of the political system."