The Greek poet Archilochus wrote, "the fox knows many things, but the hedgehog knows one big thing."
There are many different interpretations of this parable, but psychologist Phil Tetlock argues it's a way of understanding two cognitive styles: Foxes have different strategies for different problems. They are comfortable with nuance, they can live with contradictions. Hedgehogs, on the other hand, focus on the big picture. They reduce every problem to one organizing principle.