Jerzy Neyman received the National Medal of Science "for laying the foundations of modern statistics and devising tests and procedures that have become essential parts of the knowledge of every statistician." Until his death in 1981 at the age of 87, Neyman was vigorously involved in the concerns and controversies of the day, a scientist whose personality and activity were integral parts of his contribution to science. Through conversations with Neyman as well as the author's access to his personal and professional letters and papers, this book presents the life story of the statistician.