Real businesspeople operate in âlarge worldsâ, in which problems are ill defined and there are no objectively correct answers. Moreover, the ârightâ answer will often not be apparent, even in retrospect. Effective decision-makers in large worlds are not maximising; they do not have and never can have the information needed to make the relevant calculations. They confront radical uncertainty. Often they not only do not know what will happen but do not even know the kinds of things that might happen. Although we must abandon âthe pretence of knowledgeâ, individuals, institutions and businesspeople need to act in the face of uncertainties.