"There is a fundamental moral difference between a man who sees his self-interest in production and a man who sees it in robbery. The evil of a robber does not lie in the fact that he pursues his own interests, but in what he regards as to his own interest; not in the fact that he pursues his values, but in what he chose to value; not in the fact that he wants to live, but in the fact that he wants to live on a subhuman level."