Book excerpt: This historical and biographical text explores the numerous up-and-down stages of Gertrude Stein and Ernest Hemingway's friendship, one of the most fascinating and instructive literary associations of the twentieth century. Over a span of twenty-four years, they moved from a mentor-student relationship to a rivalry between artistic peers. Despite dramatic fluctuations--of love, admiration, jealousy, resentment and name-calling--their association endured, partly because of Stein's admitted "weakness" for Hemingway and his need for her approval. By incorporating unpublished material from the Hemingway Collection at the John F. Kennedy library in Boston, the text shines new light on this famous friendship.