Human beings are perhaps never more frightening than when they are convinced beyond doubt that they are right.
Source: The Lost World of the Kalahari, 1958.
-- Laurens Van der Post, ( 1906-1996), South African writer, philosopher; He is best known for his books in the mixed genre of travel, anthropology, and metaphysical speculation, e.g., The Lost World of the Kalahari, 1958.