A guide to lateral, counter, and critical thinking. "I know that I know nothing," Socrates already recognized. However, how we actually deal with the unknown, with what we do not know, and ideally should deal with it, is described by risk researcher and essayist Nassim Nicholas Taleb in his handbook. He reveals the limitations of our data obsession as well as the consequential errors and biases in our thinking. He shows how cognitive errors, false categories, and blind spots repeatedly mislead us - and how we can profitably deal with ignorance. Because: "For one person, a mistake is merely a mistake; for another, it is information.".