I am a liberal. Unlike Ronald Reagan, I believe that government is not always the problem, that very often it can be the solution. I believe in government programs for the poor, for education, for the elderly and for minorities who don't get an even break. Sen. Paul Simon (D-Ill.) believes in those things, too, but I cannot believe in Simon. He has half a message. In politics that's worse than none.

The first part of the Simon message is thrilling. Here is an old-time liberal who, in the age of Reagan, is unafraid to speak of what the government can do -- and where. Simon mentions a national school system that ill-prepares America to compete internationally: foreign languages are neglected. Advanced science (physics, for instance) is hardly taught, and the drop-out rate in some places is over 50 percent. Simon calls that a waste and says the government not only can do something about it but knows how to do it. Right on, as they used to say.

Simon talks with conviction about the underclass, the very poor who both sap society's wealth through welfare programs and menace it on the street. Something must be done, Simon says, and indeed he is right. He is right, too, about the threat that looms over the elderly -- penury through protracted illness. It's wrong for a lifetime of savings to go from the bank account of the aged to those of nursing-home operators.

That's the first part of the Simon message, and it's downright bracing to liberal ears. His program and his demeanor undoubtedly account for Simon's phenomenal rise in the polls. He now leads all Democratic presidential candidates in Iowa, a state whose Democratic Party is to the left of most others. In a comforting baritone, Simon rejects what he calls "the Reagan mind-set" -- limited government and limited funds to pay for it all.

But it's Simon who's afflicted with the Reagan mind-set. To pay for the programs of liberalism, he has recruited the president's bookkeeper. Simon's proposals would mean more spending -- a New Dealish jobs program, for instance. He is quite specific about that. But Simon is incredibly foggy about where the money would come from. His three-point program to balance the budget in three years is a tripod of wishful thinking.

Point one is a reduction of 1.5 points in the unemployment rate. But that rate is already low (under 6 percent), and it's not clear a federal jobs program would make much of a difference. Simon would also reduce interest rates, but just saying that won't make it happen. The Federal Reserve Board sets the interest rate -- not the president -- and it does so by taking into account a myriad of economic factors.

Simon's third point envisions $20 billion in cuts from the Pentagon budget. Bully! But where? Here, again, Simon is imprecise. He mentions no weapons programs, saying only he would cut waste and tighten up procurement procedures. Every president says that and every president tries. But Pentagon waste, like welfare cheating, is a given. It comes with the territory.

What Simon will not mention is (Point 4?): a tax increase. He will not even mention taxes couched in the stirring rhetoric of liberalism -- a call for the rich to help the poor. But that, really, is the essence of liberalism, and it was incorporated in the progressive tax system that was recently junked by a tax reform act Simon was among the few to oppose. While the tax reform act took some 6 million poor off the tax rolls, it also lowered rates for the rich. Under Reagan, the highest tax rate has gone from 70 percent to a planned 28 percent.

Of course, to propose a tax increase is politically perilous. Walter Mondale did it in 1984, and he's now practicing law in Minnesota. But the appeal of Simon is his own counterpackaging. He frequently evokes Harry S Truman and proclaims himself something new under the political sun -- an old-fashioned politician who's not afraid to tell it like it is. It is not unfair to hold Simon to his own standards. His economic program doesn't tell it as it is. It tells it as he would want it to be -- or as he thinks we want to hear it.

Twice I have listened to Simon explain his proposals. On both occasions, his answers were vague -- a heartening recitation of liberal intentions followed by a disappointing explanation of how they would be funded. On both occasions, his inquisitors were disappointed. They wanted from Simon what he says he will deliver: the intention to revive needed social programs plus a way to pay for them. Simon offers one but not the other. On this score alone, Simon is no Truman. That president said the buck stopped with him. Simon says it's in the mail.