I feel the article takes a widely useful human capability and isolates it to a set of negative, socially contingent actions. Revenge is a social thing. Anger is

I feel the article takes a widely useful human capability and isolates it to a set of negative, socially contingent actions. Revenge is a social thing. Anger is not necessarily social. I can get angry at the mess and thus promptly put things in order. It seems to me Nelson Mandela used his anger strategically. It wasn't that he wasn't angry, and that the derivatives of non-anger were the golden solution. After all, as the article mentions—but here in my phrasing—his strategy collapses into violence when non-violence won’t work, and then virtuously claims it is based in non-anger (the favored party always uses violence "correctly" and instrumentally as a last resort, while the opponents are seen as just angry and violent). Mandela was angry, but he used it under the disguise of a set of virtues he deemed superior to those he hated. He likely idealized himself as a non-violent person, but was deeply angered—and, in my view, there's nothing wrong with that. His strategy being a long-term one. I do not know too much about Mandela, and these are my speculations grounded mostly in psychological observations, which makes me not easily believe things are as they appear. Anger is highly productive in an often harsh evolutionary framework.