He speaks to the future in the phrases of the past. He believes, as he once told a class at his alma mater, that "we must learn from yesterday to have a better tomorrow." He quotes from Tom Paine, Thomas Jefferson, Mark Twain and Franklin Delano Roosevelt, and sees Soviet expansion in much the same way Roosevelt did Nazi aggression. At age 69, Ronald Wilson Reagan, a cultural Democrat, has become the last best hope of Republican conservatives to capture the White House.

He sees a complex world in starkly simple terms. "For many years now, you and I have been shushed like children and told there are no simple answers to complex problems that are beyond our comprehension," he has said. "Well, the truth is that there are simple answers -- just not easy answers."

He celebrates traditional values, and his vision of America is constructed of textbook images frozen in time. In a 1978 speech, he put it this way: "At the heart of our [Republican] message should be five simple, familiar words. No big economic theories. No sermons of political philosophy. Just five short words: family, work, neighborhood, freedom, peace."

The foundation has helped Reagan hold fast to his convictions as the world around him has changed. And in 1980, his rhetoric of a "new coalition of shared values," in which he links opposition to abortions, support of school prayer and the assertion that inflation threatens the structure of the family, has taken hold with the blue-collar, ethnic voters of the Eastern and Midwestern cities.

The Reagan gospel has changed little since he began speaking for General Electric on the banquet circuit a quarter century ago, even less since he first burst into public consciousness with a rousing television speech for Barry Goldwater on Oct. 27, 1964.

Today he believes that public opinion has swung around to his way of thinking. His bristling anti-Soviet declarations have become commonplace. His advocacy of smaller government and reduced taxation is conventional wisdom among Republicans and growing numbers of Democrats.

Though the world has changed, Ronald Reagan has not. That is the basis of much of his appeal in this campaign -- and also the fact that most troubles many of his critics.

He is still the prohibitive favorite to win the GOP nomination, despite his loss to George Bush in the popularity vote in Pennsylvania on Tuesday, and as never before, he is coming under public scrutiny.

This is what he belives:

"I have always talked generally on one subject -- the growth of government," Reagan has said in explaining the evolution of his basic message, which became known even to him as "The Speech."

In opposing that growth, Reagan has favored the sometimes competing objectives of a balanced budget and federal tax reduction. He has called for "true tax reform that will make at least a start toward restoring the American dream that wealth is denied to no one." He advocates complete abolition of federal inheritances taxes. He would abolish all federal taxes on savings account interest, a move he says would encourage capital investment. o

"No nation has survived the tax burden that reached one-third of the nation's income," Reagan said in 1964, in adovacting reduction of federal taxes as a pre-condition for "preserving freedom." Reagan's present support of the 30 percent, three-year federal income tax cut proposed in the Kemp-Roth bill is consistent with these views.

Reagan believes that industry must be freed from government controls of all kinds.

"Punitive taxes on business and industry should be changed, and a multitude of unnecessary regulations canceled to increase productivity," he says.

His remedy for the energy crisis is to unleash the oil industry, and the coal and nuclear companies. He opposed the recently enacted oil profits tax.

The former California governor favors increased burning of coal and the removal of "unncessarily restrictive federal rules" he says discourage its use. While Reagan says that solar power and fusion offer the hope of a "truly bright energy future," he believes that nuclear power will be a mainstay of U.S. electrical generation for the next quarter century and should be encouraged. He extols the nuclear industry's safety record and says opposition to nuclear power is based on "myth" and "superstition."

Reagan takes a similar stand on agriculture. In a televised speech in Des Moines last Jan. 19, he said: "The energy industry and agriculture have something in common; if we turn both loose in the marketplace without government interference, they'll deliver the fuel and food that we must have."

Reagan says that federal policies have favored a "cheap food policy" benefiting consumers at the expense of farmers.

In foreign policy, Reagan believes the United States needs a powerful nuclear arsenal to deter the Soviet Union.

"I favor development and deployment of the neutron warhead for U.S. theater nuclear forces, including balistic missiles, cruise missiles, artillery and bombs," Reagan said in a Jan. 31 policy statement.

He contends that the grwoth of Sovieet strategic nuclear power threatens the ability of U.S. land-based nuclear forces to survive a first strike.

Reagan's view of America's role in the world was formed at a time when President Roosevelt, an early Reagan hero, was struggling to ally the United States with foes of Nazi Germany in the face of domestic opposition that wanted no part of a European war. Without mentioning Roosevelt's war. Without mentioning Roosevelt's name, Reagan often quotes from his Dec. 30, 1940, radio speech in which Roosevelt declared. "We must be the great arsenal of democracy."

Reagan still believes in that role. He favors sending arms to the Afghans who are resisting the Russian invaders, and says that the United States should not shrink from confrontation out of fear of Soviet nuclear power.

"We are being asked to buy our safety from the threat of the [atomic] bomb by selling into permanent slavery our fellow human beings enslaved behind the Iron Curtain, to tell them to give up their hope of freedom because we are ready to make a deal with their slavemaster," Reagan said in his 1964 speech for Goldwater.

Now, Reagan accuses President Carter of a policy that "borders on appeasement" in dealing with the Soviet Union. Reagan contends that the administration suffers from a desire "to be liked" around the world.

Reagan criticizes Carter for scrapping the B1 bomber and for "delaying or postponing the cruise missile program, the MX and the Trident submarine." oBut Reagan has yet to settle on the specific new strategic weapons systems he would favor to counteract the Soviets.

"Gov. Reagan believes that a new generation of strategic bombers is needed to replace the outmoded B52s," said Reagan chief of Staff Edwin Meese last week. "What he hasn't decided is whether this should be an improved version of the B1 or some other strategic bomber."

Reagan puts no dollar figure on how much the defense budget increase should be, saying simply that the United States must spend "whatever is necessary" to maintain military parity with the Soviet Union.

Reagan's defense views are based on a long-standing conviction that the Soviets are out to rule the world. Asked in a Dec. 19, 1979, interview with The New York Times why the Soviets had spent so much on arms, he replied: "Every Russian leader, every Soviet leader from the very beginning has . . . proclaimed to their own people their belief in the Marxian philosophy that communism can only succeed if it is a one-world communist state, and they are going to aid social revolutions all over the world until the whole world has been liberated to communism. And I think this explains what they're doing."

In almost every speech of the 1980 campaign, Reagan has mocked Carter's 1977 declaration that "we are now free of the inordinate fear of communism which led us to embrace every dictator who shared that fear."

Reagan believes that it is necessary for the United States to support countries that oppose communism, whether they are ruled by dictators or not. He has spoken glowingly of South Korea, of white-ruled Rhodesia, of Singapore and of the deposed shah of Iran, whom Reagan said the United States should have kept in power. Reagan almost certainly would put new pressure on Castro and Cuba, which he suggested earlier this year should be blockaded as an appropriate response to the Soviet invasion of Afghanistan.

The two countries that have earned the most admiration from Reagan over the years are the Republic of China, as the government on Taiwan calls itself, and the state of Israel.

Reagan has been pro-Isreal since the creation of that tiny nation in 1948. He maintians that the U.S.-Israeli alliance is of more value to this country than to Israel because the Israelis provide a counterweight to the Soviet Union in the Middle East.

"Israel, a stable democracy sharing our own values, serves as a vital strategic asset with its highly trained and experienced military forces, and is a deterrent to Soviet expansion in that troubled part of the world," Reagan said in a foreign policy speech in Chicago on March 17.

Reagan has been equally staunch in his support of Taiwan. He said at a Shreveport, La., fund-raiser recently that he would give official status to the American Institute in Taiwan, which has handled U.S. affairs in Taiwan since the United States broke diplomatic relations with the Republic of China on Dec. 31, 1978 and "normalized" its relations with the People's Republic of China.

"One of the things that struck me most was that the people of Taiwan smile so much," Reagan said in a speech to the Chinese Consolidated Benevolent Association on July 17, 1978, after returning from a trip to Taiwan.

On social issues, Reagan is committed to a federal constitutional amendment allowing abortions only to save the life of the mother. He is against gun control, while advocating stiff prison sentences for anyone who carries a gun during the commission of a crime. He favors the restoration of school prayer, opposes "court-ordered compulsory busing," and wants to abolish the newly created federal Deaprtment of Education.

He opposes the federal minimum wage, which he says "destroys thousands of jobs for the poor and young," a position some of his aides believe has appealed to black Americans.

His attitude toward women reflects the social outlook of an earlier day when women were tied to the home and worked in paying jobs only out of economic necessity. Inflation, he said when he declared his candidacy in November, "threatens the very structure of family life itslef as more and more wives are forced to work to help meet the ever increasing costs of living," ignoring the growing number of women who work now for the sake of careers.

Ronald Reagan believes that out of his views, a new coalition is building, a coalition whose banners pay homage to the past.

While the world has been changing from one in which American power and resources were paramount to one in which power and resources are dispersed, Reagan still sees the U.S. role in World War II terms, just as he sees economic issues in the images of the Great Depression.

More than anything, in a world that seems beyond the grasp of the ordinary citizen to control or even understand, he says that the old ways were best.