"Rich people sure don't like to tip," the cabbie complained as he picked me up near the brokerage house. "I just brought this guy down here, and . . ."

"You brought a fare to this brokerage?" I demanded.

"Yeh, and all he . . ."

"And do you know what those people do?" I said. "They sell krugerrands, that's what. As I recall, you're the guy who gets all sad-eyed when he talks about the plight of black South Africans, and here you are helping them to sell their blasted gold coins. Well, I hope you enjoy your blood money."

"Blood money?" the cabbie said. "It wasn't but a one-zone ride, and the dude only tipped me a . . ."

"Principle," I said. "It's a question of principle. American investments in South Africa help to keep that racist regime afloat. I thought everybody understood that now, what with all the college campuses and civil rights leaders and decent people generally calling for disinvestment. And what do you do? Why, you drive some guy down here who, for all you know, wants to purchase a boatload of krugerrands."

"I'm sorry, man," the cabbie said. "I guess I just didn't think it through. I suppose you've disinvested all your South African holdings?"

I acknowledged that I didn't, at the moment, happen to be in the stock market, but that I was making sure my alma mater purged its portfolio of tainted stock.

"In other words," the cabbie said, "disinvestment is not costing you anything personally?"

"Disinvestment is bigger than the economic concerns of any one individual," I told him, blunting the thrust of his impertinence. "It's a moral question, and each of us has to do what he can to undermine the economics of that country in order to defeat apartheid. You'd understand that if you knew how black people suffer under that regime."

"And undermining the South African economy eases the black man's suffering?" he said. "Looks to me like we might just be putting a lot of black people out of work."

I had heard that mealy-mouthed argument before, and I was ready for it. I told him that black people in South Africa were used to suffering, that it was the white regime that would be brought to its knees -- either at the bargaining table or on the battlefield. "I don't tell you that black people won't be hurt to some extent," I said, "but every revolution requires sacrifice."

"I see that," the cabbie said, "but it looks to me like you're trying to force the black South Africans to do some sacrificing they'd rather not do, otherwise they wouldn't be working for those racists in the first place."

I tried again to explain it, but he still didn't quite understand.

"Here's where I get hung up," he said at last. "I had this uncle in Mississippi who was in such bad shape that he finally decided to become a sharecropper on this white man's plantation. Conditions were terrible. The roof leaked; he had to haul his water from a well; the children had to work for the man when they should have been in school, and he cheated my uncle every chance he got. I told my uncle that he should leave that place, but he told me that at least his kids were eating.

"I keep thinking what my uncle would have said if folks like you had organized a big cotton boycott. It probably would have bankrupted the white man who ran that plantation, and I'm here to tell you that he would have deserved it. It would've done my heart good to see that old rascal lose his farm and have to go on welfare.

"But my question is, what good would that have done for my uncle?

"Don't get me wrong. I wouldn't have invested a dime to keep that crook in business. But it looks to me like the thing to do would be to find some way to help my uncle: maybe find him a job or help him buy a little piece of land for himself. What I want to know is, how would hurting that white man have helped my uncle?"

"For your information," I said, "Mississippi and South Africa are different."

I tipped him a dime and got out of