Taking his cue from a brief comment by an obscure Greek poet, Isaiah Berlin made a famous taxological distinction between intellectual hedgehogs and foxes. Intellectual hedgehogs know "one big thing." They have a key insight that gives them a perspective from which to view and discuss many different problems. Intellectual foxes "know many things." "Foxes" have many different and sometimes unrelated insights, flashes of insight and understanding that come from many different sources. When you meet a hedgehog, it's a fair bet that you can make an informed prediction about what she or he will say about many different subjects. At least, you may be able to do this if you have an understanding of the Big Underlying Insight that unifies the Hedgehog's thought. But when you meet an intellectual fox, it wiU be difficult to predict his or her perspective or opinion in novel domains. Those who have more tools to choose from have more available options, and the reason the fox is hard to catch is that it is harder to predict.