Hawaii, celebrated as the land of pineapples and paved-over paradise, is looking forward to the day when it will no longer support itself on the twin pillars of tourism and military spending.

State Sen. T. C. Yim, chairman of the State Energy Committee, has proposed a plan that would make the nation's 50th state self-sufficient in energy except for jet fuel.

And in a soon-to-be-submitted State General Plan, the first document of its kind in the United States, Gov George R. Ariyoshi looks forward to a state that he says he believes will develop its own aquaculture, flower industry, forestry, magnesium, motion pictures and skipjack tuna cannery and fishing fleet.

"If any of these challenges materializes, we'll have enough opportunities for our young," says State Planning and Development Director Hideto Kono.

Hawaii is at once unique and microcosmic of the West. It is unique is that it is an island state and the only American-state whose ethnic roots and historical perspectives are more in Asia than in Europe. It is microcosmic is that Hawaii, like California and Colorado before it, is a fading utopia where unremitting promotion of tourism has destroyed many of the values that brought tourists there in the first place.

Californians, who frequent Hawaii in increasing numbers, look sympathetically and a bit wistfully on the efforts of the islands to preserve their amenities. In much of California and the rest of the West that effort has been lost to the pressure for economic development.

Only a few years ago conservationists were on the ascendancy in the West, and bumper stickers in Denver proclaimed, "Don't Californicate Colorado." Now Denver has some of the highest pollution levels in the country, and the conservationist movement is on the run. At Lake Tahoe, mid-summer air-pollution levels created by traffic jams now exceed those of Los Angeles.

There is smog in Hawaii, too, but there also is a considerable determination - and a larger necessily because of the small land area available - to preserve the still-unspoiled natural beauties of the "neighbor islands" surrounding Oahu, the main island.

More than 3.2 million people visited the islands in 1976, 4 times the number of a decade ago and 4 times the present resident population.

Many of the tourists head straight for the Waikiki strip on Oahu, a tall strand of high-rise hotels whose shadows block out the sun on the beaches. However, enough tourists are now discovering that "nieghbor islands" - especially Maui and Hawaii - that the residents are becoming worried that they will one day go the way of Waikiki.

The economic importance of tourism is underscored in the summary of the recently prepared State General Plan, which is to be presented to the 1978 session of the state legislature.

"If tourism quit growing tomorrow, unemployment would average 19 per cent between 1975 and 1980 and 13 per cent between 1980 and 1985 . . .," the report says.

Against this background, the proposal of the state plan to hold tourist grwoth and hotel construction to 7 per cent annually strikes some developers and businessmen as radical.

The state's tourist-oriented economy also is fragile in most other respects Military spending is the second-largest source of income, but in an age of technological warfare and fewer large naval vessels, which require the advantage of Oahu's deep harbors, the military future is highly questionable.

Questionable also is the outlook for the state's two largest agricultural crops, sugar and pineapples. The sugar economy has been shaky ever since Act in 1974, though the Carter administration's subsidy program for domestic sugar has given recent encouragement. But competition from cheap-labor countries in Asia and Central America has crippled the pineapple canning industry.

Some farmers now believe that Hawaii must simultaneously preserve its remaining agricultural lands and broaden the base of a farm economy that produces less than half of the vegetables and fruits and less than a third of the meat consumed on the islands.

However, much of the best land already has been lost. Recently, at a federal-state seminar in Honolulu, a map showing the state's choice farm lands in the Pearl City and Pearl Habor area was projected on screen. A groan went up from the audience when another map was superimposed on this one showing that most of this farmland already was in urban use.

Perhaps the most far-reaching expression of Hawaii's new interest in managing its own resources is Sen. Yim's general proposal, which calls for the island of Hawaii to be energy self-sufficient by 2010.

Among other things, Yim's plan would require that all cars and trucks on the island use ethanol made from island crops as fuel. Geothermal steam from the islands' still-active volcanoes would provide a third of Hawaii's electrical energy needs. Hawaii already receives 120 megawatts of power from the burning of the sugar cane residue known as bagasse.

Whether any of this will happen in Hawaii, the state with the longest life-expectancy rates and the biggest supply of perennial optimism, is difficult to tell.

Herbert C. Corneulle, president of Dillingham Corp., an investment combine, and regarded as one of the islands' most progressive businessmen, questions whether there is adequate political determination in Hawaii to carry out the glowing goals of the general plan.

"Real planning is deciding," Corneulle says. "It means scoring touchdowns, not just deciding where the goal line is. We lack a sense of conviction about where they we're going. Purposelessness is a hell of a disease in Hawaii."

This nation of "purposelessness" is echoed by politicans and other citizens in Hawaii, many of whom seem at a loss to know what they want their state to become.

"What we need to do is revive the determination and the dream we had a statehood," says Honolulu Advertiser editor George Chaplin. "There was a feeling we could climb any mountain and that life would always be beautiful."

That feeling is subtly different now.

"Tourism is one big party," says a local contractor, who watched his tiny business become prosperous in the Waikiki hotel boom. "We know it can't last forever and that it won't last. But it's hard to realize this when everyone's having such a good time."