Nelson Mandela by Mary Benson; foreword by Bishop Desmond M. Tutu (Norton: $16.95, hardcover; $7.95, paperback; 230 pp.) : PART OF MY SOUL WENT WITH HIM by Winnie Mandela; edited by Anne Benjamin and adapted by Mary Benson (Norton: $14.95, hardcover; $5.95, paperback; 164 pp., illustrated)

After almost a quarter of a century in prison, Nelson R. Mandela is much more than the black leader he was when he was jailed for life after a South African court convicted him of sabotage and attempting to overthrow the country’s minority white regime. At home and abroad, he has become the symbol of the long struggle against apartheid by South Africa’s black majority.

As a political figure, Mandela is almost invisible: He has not been seen or heard by most South Africans, whether they be his supporters or his opponents, and many of those militant young blacks in the front lines of the the anti-apartheid campaign today were born after he was jailed.

Except for his refusal to compromise with apartheid, even if compromise would bring his freedom, little is known about Mandela’s views on South Africa’s deepening crisis, on how it might be resolved and what future he envisions for the country. What he would do were he released from prison is purely a matter of speculation.

Yet, Mandela, now 67, inspires blacks in a way that no other South African leader does, and over the past year, he has become in the minds of many South African political observers, whites as well as blacks, an increasingly indispensable element in the peaceful resolution of the conflict here.

Even President Pieter W. Botha has, in effect, recognized Mandela’s unmatched stature as a black nationalist leader--a confession of the government’s own failure to turn him into a non-person after his 1962 imprisonment--by trying to work out terms for his release, only to be rebuffed by Mandela’s refusal to accept any conditions for his freedom.

The unconditional release of Mandela, however, is a much bigger move than the Botha government appears politically prepared to make. The inescapable implication of his release today would be legalization of the African National Congress, banned in 1960, and negotiation with it on a new, majority-rule constitution.

Mary Benson, an old Mandela friend from the 1950s and 1960s, has written a new biography of the black leader in an effort to explain his centrality to the anti-apartheid struggle even after years in prison and (one quickly concludes) to enhance his image internationally and thus increase pressure on the South African government for his release.

Benson sketches the growth over the past four decades of the African National Congress under Mandela, Oliver Tambo, Walter Sisulu and other veteran revolutionaries, all now in prison, in exile or dead. The book becomes a very readable history-from-within of the struggle against apartheid.

Mandela, a lawyer by profession, is quoted at his most eloquent in organizing the early campaigns against the system of racial separation imposed after the National Party came to power in 1948 and in defending the decision of the African National Congress to begin an armed struggle after the fatal police shooting of 69 blacks at Sharpeville in 1960. Mandela the Political Legend takes on a more human form as Benson recalls his personal charisma, his courting of a young social worker, Nomzamo Winnie Mandela, and his life on the run as the “black pimpernel.”

But Benson, a white South African who fled the country after being put under house arrest and banned from politics by the government, has clear biases. Her portrayal of Mandela, the African National Congress and the South African Communist Party is rarely critical, and thus she fails to ask whether there are alternatives to their strategy and why the congress--at 74 perhaps the world’s oldest liberation movement--has made so little progress. Exiled in London for nearly 20 years, Benson does not fully perceive the kaleidoscopic changes in her homeland over the past 18 months.

Mandela emerges more forcefully, both as a political leader and as a man, in his wife’s autobiography, which is based on a series of interviews interspersed with comments by friends. Speaking as much about him as about herself, Winnie Mandela recalls discovering in the first days of their marriage: “You couldn’t tear Nelson from the people, from the struggle. The nation came first. Everything else was second.”

From Winnie Mandela, 49, speaking from her heart and from her own almost continuous persecution since her husband was jailed, come the explanations of why South African blacks are so angry today and why they will not quit until they have won. An American will find it impossible to read her story without sharing her rage. Recalling the humiliation she saw her schoolteacher father suffer at the hands of whites, Winnie Mandela says, “It hurts your pride as a child. You tell yourself, ‘If they failed in those nine Xhosa wars in the nineteenth century tribal conflicts with European settlers, I am one of them, and I will start where those Xhosas left off and get my land back.’ ”

Peace will not come to South Africa, Winnie Mandela says, through whites’ giving blacks bits and pieces of power but only through a complete sharing of the political power and the wealth of this country. Echoing the declarations of Nelson Mandela 25 years ago, she says that among blacks, “there is an anger that wakes up in you when you are a child, and it builds up and determines the political consciousness of the black man.” And this, she says, is not the position of radicals and revolutionaries, as the government charges, but simply of proud people determined not to put up with apartheid any longer.