An exciting probe of the great discoverer and the countless enigmas surrounding his life and legacy. Pulitzer Prize-winning New York Times science correspondent Wilford (Mars Beckons, 1990; The Riddle of the Dinosaur, 1985; The Mapmakers, 1981) sifts through the legends that have encrusted Columbus ``to review and assess the numerous questions that persist and cause such heated dispute among historians.'' No mean task: the proud and secretive navigator left a host of enemies and the wispiest of paper trails at his death, with his subsequent reputation veering wildly between neglect, admiration (Samuel Eliot Morison's Admiral of the Ocean Sea), and revisionism (Kirkpatrick Sale's Conquest of Paradise). In his superbly balanced portrait, Wilford depicts the navigator as an intelligent, indomitable, courageous mariner hopelessly at sea as a colonial governor. Acknowledging that ``the burden of the practices Columbus initiated or condoned weighs heavily on his reputation in history,'' he examines with moral sensitivity the admiral's responsibility as progenitor of the Black Legend, Spain's ``burden of violence and destructive greed'' that included the enslavement and killing of Native Americans. Even more useful, however, are his discussions of recent archival and archaeological discoveries related to Columbus, including his origins, how he conceived his plan to discover the Orient by sailing west, why Ferdinand and Isabella of Spain supported his quest, his initial landfall in 1492, his ships, even where he lies buried. Most fascinating of all, Wilford speculates that Columbus saw himself as God's messenger, sent to help Spain recover the Holy Land lost to the Moslems. A crisp, highly readable account of Columbus as man and symbol, and of how the first momentous encounter between the Old and New Worlds has been interpreted and reinterpreted over the last five centuries. (Three maps.)