CETA is about to give up the ghost. On Sept. 30, the Comprehensive Employment and Training Act will lose its federal funding, and without that life support system it will be handed over to the doctors of mortuary science. I hope they lay the corpse out with proper solemnity.

In its lifetime it was the subject of intense public policy debates. It supplied the Republic with every sort of toiler from chamber music players to street sweepers, from computer programmers to goldbrickers. It cost a fortune, over $5 billion in fiscal 1979 if you count only public service employment. If you add in various public training and youth programs the bill came to nearly $9 billion.

Whether CETA was a successful public employment and training program I leave to those social scientists whose lives are devoted to such causes. However, I would point out that the Labor Department is predicting that by Sept. 30 no more than 20 percent of our present CETA workers will find jobs in the private sector. Most of the others will scud over into what public service jobs remain, or they will collect unemployment checks.

CETA's expiry is coming just as another great policy debate is beginning to elicit spasms of concern in our nation's capital, a debate whose issues are reminiscent of the great CETA debates. The question now is whether the Reagan policy of tax and spending cuts can revive the economy. Those who deplore Reaganomics say the administration policy is already a failure, as can be seen from our high interest rates and the declining stock market. Moreover the cuts are denying opportunity. Those who celebrate the administration's policies hoot at this criticism, pointing out that they have yet to be implemented, let alone tested. Moreover the cuts are essential for increased opportunity.

Well, I favor the Reagan cuts, but my expectations are more modest than those of either side in this debate. Both suffer from the same delusion that afflicted the advocates of CETA, namely: the delusion that government policy can evoke marvels from us all. Unfortunately there is more to a society's prosperity than economic policy. Can proper marginal tax rates or job training turn a man who is tone deaf into a Toscanini? No leader will come up with a policy that will induce everybody to become a Rockefeller. No tax incentives will move all of us to such feats of capitalist endeavor. Some of us will be satisfied with modest incomes.

The problem with the administration's gathering mob of critics and advocates, both of whom place so much emphasis on government policy, is that they see mankind too narrowly and government too radiantly. Both somehow believe that there is a way to trigger us all toward economic valor. Their grand economic interpretations are overblown. Mankind is too diverse for this sort of social engineering. In the end these policy advocates suffer delusions not unlike those held by such other great simplifiers of humanity as Marx and Freud, two of history's greatest pests.

This is not to say that government policy will have no effect. The success of the Reagan cuts depends on how many people actually are sensitive to policies that stimulate economic activity. Are there enough Americans willing to work and to save, once the yoke of government is lifted from them, thus returning the economy to prosperity; or is the industrious Yank of yesteryear lost to history? Has he become satiated by affluence, or too confused by the rhetoric of the New Age Liberal, to take a job and work at it?