Psychologists, sociologists, philosophers, historians, and even scientists themselves have often tried to decipher the basis for creativity in science. Some have attributed creativity to a special logic, the so-called scientific method, whereas others have pointed to the inspirations of genius or to the inevitable workings of the zeitgeist. Finally, some have viewed scientific breakthroughs as the product of chance, as witnessed in the numerous episodes of serendipity. Too often these four alternative interpretations are seen as mutually exclusive. Yet the central thesis of this book is that the chance, logic, genius, and zeitgeist perspectives can be integrated into a single coherent theory of creativity in science. But for this integration to suceed, chance must be elevated to the status of primary cause. Logic, genius, and zeitgeist still have significant roles to play but mainly operate insofar as they enhance, or constrain, the operation of a chance combinatorial process.