The searing problems of southern Africa require not only the nuts and bolts of negotiation but the climate of a common humanity. When adversarial leaders meet as individuals of good will, the results cannot be measured in items on a communique. In this light, there is encouragement in the get-together between Prime Minister Botha of South Africa and President Kaunda of neighboring Zambia.
After last week's talks of close to four hours, they claimed no breakthroughs on the range of topics discussed, said to include independence for Namibia and release of black leaders in South Africa. But a Zambian spokesman remarked that ''each person spoke from the depths of his heart.'' The more such depths are plumbed on all sides the more the nuts and bolts can be made to fit.