SEN. HOWARD METZENBAUM was going after David Stockman, at a hearing the other day, for the cuts that the administration has proposed in aid for the poor. Never a man to understate his view, the senator called Mr. Stockman cruel and inhumane. Mr. Stockman replied that slow economic growth can inflict greater suffering on the poor than any of the budget cuts that he has in mind. For poor people, he argued, the greater cruelty would be toleration of economic policy that fails to create jobs.

Mr. Stockman is quite right to emphasize the stake that everyone, and especially everyone who's poor, has in steadily rising employment. Even if you would not necessarily have chosen precisely the same welfare cuts as Mr. Stockman, the broad purpose -- to make the economy grow more surely, with less inflation, by cutting taxes and budgets -- is an altogether rational one.

Now for a caution: The administration, and a great many other people, have been talking in the most extravagant terms about the terrible state of the economy. It is alleged to have falled into such dire straits that its condition justifies even the sharpest swerve to new precepts. In this atmosphere it's easy to foreget that, in some respects, the economy has been performing rather well. In what respects? In, above all the creation of new jobs.

Late last year, most forecasts warned of rising unemployment rate in February, at 7.3 percent of the labor force, was substantially higher than the rate of 6.2 percent a year earlier. But there were actually more people employed last month than the winter before. The explanation is the rapid growth of the labor force. Part of it is due, as you might expect, to the high birth rates 20 years ago. Another substantial part of it results from the strong and continuing trend among women to seek and find jobs. When the unemployment rate sticks on a plateau, it doesn't mean that no new jobs are being created. It means that jobs are being created only as fast as people are coming into the market to look for them.

Everyone would like to see them created a little faster, to bring the unemployment rate down. But it's important not to misjudge the magnitude of recent progress. Americans commonly think of the 1970s as a time of economic stagnation. Over the decade, from 4 million to the present 7.8 million -- not a happy development. But in the same period, since 1970, the American labor force has risen from 83 million people to 106 million. There are 19 million more jobs now than there were in 1970. That is a staggering increase -- and a much larger one, incidentally, than in the booming 1960s.

It's true that much has gone wrong in recent years. But the American economy has continued to expand and to employ most of the people who came looking for work. It is important for officials who make policy not to let themselves be captured by the currently fashionable rhetoric of crisis. The economy has not stopped growing. It is showing signs of malfunction, and the inflation rate is dangerously high. Mr. Reagan likes to evoke the example of Roosevelt and the Hundred Days to indicate the scale of the changes that he wants to undertake. Bvut there's been no crash. Even after the unpleasant surprises of 1980, with its wildly high and instable interest rates, business has been expanding and employment has been rising again. It is a time for careful experimentation in policy. But it's not an emergency that demands immediate surgical solutions. It's not 1933.