S. Africa: black split on sanctions persists. President Reagan's clash with Congress over sanctions against South Africa is mirrored in the views of that country's blacks. Some feel sanctions would hurt; others say they would have little impact; and many others are unaware that such a debate is even going on.

``Your Mr. Reagan is doing the right thing by being against economic sanctions. I admire him. What if sanctions destroy the economy here? Where are my children, and other black children, going to find jobs?'' So says John, a black South African who has spent most of his 42 years battling the twin strictures of poverty and apartheid.

His is but one voice in a ``sanctions debate'' far more complex -- more nearly a matter of life and death -- than the United States political battle culminating in the Senate-White House showdown over the Comprehensive Anti-Apartheid Act of 1986.

In the public arena, prominent black political figures such as Anglican Archbishop Desmond Tutu and moderate Zulu chief Gatsha Buthelezi have been waging a debate not dissimilar to the one between the US Congress and President Reagan. But of South Africa's 22 million other blacks, the most one can say with any certainty is that opinion is agonizingly divided.

Opinion polls -- an imperfect measure, given the gut suspicion of many blacks that they might be under political interrogation -- do suggest some trends. Rural blacks, the poorest of the poor, seem in large part to oppose sanctions. And one recent survey found that one-third of rural respondents had not even heard of the sanctions issue.

But in the black urban townships, whose young militants increasingly set the tone of black politics, many would welcome such measures taken by the international community against South Africa's white minority rulers. The recent poll found 47 percent of urban blacks favoring sanctions, while 29 percent were against such measures, and the rest were undecided.

A black social worker in the sprawling township of Soweto, who preferred not to be identified, favors sanctions. He thinks people like John are naive -- about sanctions, and about Mr. Reagan.

``It is clear,'' says this social worker, ``that Reagan does not want apartheid to go. His so-called `constructive engagement' amounts to perpetuating the status quo. People who oppose sanctions keep telling us that they'll hurt the economy. But most blacks are at the bottom of the heap anyway. When the gold price was booming a few years back, we blacks didn't feel the boom. How can you tell us we're going to feel a depression?''

Frequent visits to Soweto have brought a black American businessman here face to face with the pro-sanctions argument. He opposes sanctions. He feels that if Americans want to help South Africa's blacks, the best way to do so is by hiring blacks, and giving them the jobs and educational opportunities that they have been denied for decades. ``I pick up hitchhikers whenever I drive to or from Soweto, and we often talk about this.''

He says that despite the fact that his riders often agree with his reasoning, ``still, almost all of them say that they favor US sanctions.''

The Soweto social worker offers an explanation of such a stand. ``A group of friends and I were talking over sanctions. And the conclusion we reached is that the economic details of the issue have become irrelevant. People will lose jobs. But the main ones will be blacks working for American companies: the cream.

``The South African conflict has become a choice between two evils: the institutionalized violence of the present South African political system, and the political violence of young blacks in townships like ours. I don't like black violence. But if that is the alternative to the violence of apartheid, I think we must choose that alternative. . . . After apartheid goes, we can do away with this lesser evil.''

Similarly stark, say the social worker and other Sowetans interviewed during recent weeks, is the view of the US's overall Africa policy. When asked for comment on the views of US senators who back sanctions and say they will send a new US policy signal to blacks here, the social worker is dismissive.

Personally, he feels a fondness for America. He is about to visit the US for the first time -- on a US government grant. ``But,'' he remarks, ``I think most people in Soweto don't really make distinctions between Congress and the White House, not even between Democrats and Republicans. For the ordinary Sowetan, the conflict has become one of whites oppressing blacks.''

John, however, sees this view as both an oversimplification and a political luxury. ``Yes, there are lots of wrongs here that have to be righted. I was born on a white-owned farm in the northern Transvaal. My mother worked there as a laundress. We were poor. But I would go, barefoot, to school every morning. . . .''

Having graduated from high school, John has spent the past two decades working in hotels and restaurants. He lost a good job several years ago -- when South African ``pass laws,'' now repealed, barred his joining the restaurant owner in a new location outside Johannesburg. But he has now become head waiter at one of the city's top restaurants.

``I can't live here with my wife and two children. But I visit them, on my one month's vacation, each year. Even in the countryside, there are now great pressures for my children to join the militant groups.

``But every time I go home, I spend my time telling them they must steer clear -- of all politics. They must study. They must look to the future.

``People like Tutu can afford to call for sanctions. He has food to eat. His children have traveled and studied outside South Africa. But it is wrong to create the impression that if a black government comes to power, everyone will have jobs -- that Nelson Mandela will perform miracles.

``Yes, Mandela is a good man. But no matter what happens here, for blacks or whites, people will need jobs, the ability to advance themselves and their families. We need money -- the money that foreign companies can give us.''

This report was filed under South Africa's emergency regulations, which prohibit reporters from being ``within sight'' of any unrest, any ``restricted gathering,'' or any ``police actions''; from reporting on arrests made under the emergency regulations; and from relaying information deemed subversive.