A familiar fate has caught up the latest announcement of plans for reform by South African President P. W. Botha. His supporters call for respectful attention to the considerable political distance traversed by a man who was in parliament when the Nationalist Party set up apartheid in 1948 and who now pronounces apartheid "outdated." His critics find his concessions too little and too late, and deepen their appeals for swift passage to full political rights for the black majority. In the government's reluctance to go further faster and in the determination of large numbers of the country's citizens to keep struggling for their freedom lies the tension that defines South Africa today.

Is it different this time? There is the usual hedged reform: for instance, the pass laws controlling where blacks live and work are to be phased out by July 1, but they are to be replaced by a creature called "orderly urbanization." More intriguing is the suggestion that President Botha means to bring Nelson Mandela out of prison and back into politics.

Mr. Mandela heads the leading non-tribal black political organization, the African National Congress. He is widely regarded as one of the major figures who must be at any table at which South Africans attempt to hammer out a common future. Mr. Botha's linking of his release to Moscow's freeing of two Soviet dissidents, Andrei Sakharov and Anatoly Scharansky, seems mainly a tactic to cover what hard-line Afrikaners will doubtless receive as an egregious political retreat.

There is an important principle at stake here. Until now, whites such as Mr. Botha have regarded reform as a process of controlled change directed from the top down: as a white benefaction. In these conditions, white concessions have been discounted practically upon issue, and black distrust of white intentions has flourished. The promise of the release of Nelson Mandela is that blacks can become participants in their own destiny -- in their own peaceful political destiny, that is.

All that, of course, is still far from assured. Mr. Botha says he'll create a new multiracial advisory council including blacks. He sees it as the "first step toward institutionalized power-sharing." But if there are blacks of stature ready to start down this extra- parliamentary path, it is already a question whether they can convince the awakened black political community that it's worth a try. The day of white dispensation is past.

South Africa's ruling whites keep looking to forces outside the country -- to foreign creditors, traders and investors, to the United States, in a certain curious sense to the Soviet Union -- to spare them the uncertainties of dealing directly and honestly with South Africa's blacks. But there can be no other way.