White (''The Farewell Symphony'') turns from his trademark autobiographical fiction to deliver his most fabulous novel yet, a mock memoir of real-life Scottish-born feminist Fanny Wright, as told by her friend, the likewise real-life author Frances Trollope. Wright first comes to America in 1818 and returns seven years later and creates Nashoba, a utopian community for freed slaves. Narrating late in life, Trollope describes her friend's career as an agitator and shaper of early American life -- while noting the high cost she paid living out her ideals. Wright, she concludes, was ''a blazing ten-log fire sans fire-screen.'' And in ''Fanny,'' White beautifully inhabits the bitterness of a woman who lived too close to that flame.