Serendipities is an iconoclastic, dazzlingly erudite and witty demonstration, by one of the world`s most brilliant thinkers, of how myths and lunacies can produce historical developments of no small significance. In Eco`s words, `even errors can produce interesting side effects`. Eco`s book shows how: -- believers in a flat earth helped Columbus accidentally discover America -- the medieval myth of Prester John, the Christian king in Asia, assisted the European drive eastward -- the myth of the Rosicrucians affected the Masons, leading in turn to the widespread belief in a Jewish masonic plot to dominate the world and other forms of paranoid anti-Semitism in the nineteenth and twentieth centuries