Richard Cohen's column on divestment ("An Evil Un- Simplified," op-ed, April 26) is surely simple, but it is not edifying, merely puzzling. Cohen's departure point is the description that Harry Schwarz, an opposition member of the South African parliament, gave to Cohen of Schwarz's father's sad face when the father became unemployed. Cohen apparently found this description to be so moving that it led him to a fundamental reconsideration of the tactic of applying pressure on the South African government by all available peaceful means.

At the outset, I might recommend that if Cohen wants to be moved by the faces of the unemployed, he does not have to rely on secondhand descriptions. He can go on any day to an abandoned warehouse on K Street NW between 5th and 6th and see the faces of the working-age black men who stand there because there is no work for them to do. Then, perhaps, he might be moved to employ his considerable talents to warming the cold hearts that beat in the chests of Ronald Reagan and David Stockman.

Having been moved by Schwarz's story, Cohen goes on to pick up his argument -- and that of the South African government and of American executives who, for one reason or another, want to continue to do business in South Africa. They say that pulling out American capital would hurt blacks more than it would hurt anyone else and that American firms should be left to do such good things as providing fine job opportunities for blacks and giving them educational opportunities while, though it is never mentioned in such arguments, continuing to make handsome profits in a country that is distinguished for having a brutalized and, therefore, cheap -- and heretofore docile -- labor force.

There are many problems with that argument. The first is that, though South African whites make it all the time, it does not seem to be an issue of considerable concern to South African blacks. Perhaps this is because, according to the House subcommittee on Africa, less than 1 percent of the black labor force is employed by American firms. Moreover, as Oliver Tambo, president of the African National Congress, observed here last week, many more whites than blacks would lose jobs from divestment. When Sen. Edward M. Kennedy returned from South Africa earlier this year, he told the leaders of the Free South Africa Movement that, while South African whites talked incessantly about the undesirability of divestment, not one of the blacks with whom he met ever raised the issue.

The fact is that pulling capital out of South Africa is one weapon in the hands of civilized human beings and institutions that the South African government fears the most. Former prime minister John Voerster often said, "Foreign investment is the bricks and mortar on which South Africa is built." If that government did not fear divestment, it would not have made its advocacy by South Africans a crime and it would not have developed a special office to handle the issue or have invested millions of dollars to deflect the campaign in the West.

Cohen argues that people engaged in the divestment effort and those marching at the South African Embassy to encourage Congress to force the administration into a constructive disengagement policy are simple-minded and are looking for the "moral equivalent of a free lunch." That is wrong. We know that the apartheid system cannot stand, and we worry that an even bloodier revolution than the one now occurring in South Africa will be the only way that it can be changed. We are thus attempting to apply pressure on the exact point where the South African government believes itself most vulnerable to force it into political negotiations designed to achieve a just system by peaceful means. It is outrageous of Cohen to suggest that we are hoping by our actions to make South African blacks revolutionaries. The South African government, at such places as Sharpeville, Soweto and Langa and in its shoot- to-kill policies, is doing a far better job of that than anyone else in the world could possibly do.

We who have been out on the picket lines for the past 24 weeks and have been flying around the country exhorting others to action know that there is nothing simple about South Africa. But we take our cue from our black South African friends who tell us that almost any burden that promises to bring about change is preferable to a continuation of the current system.