Because I have an eerie feeling that any attempt I make to describe what happens in this story is likely to start the summer rush for the beaches, I want to say at once that "The Color Purple" is an American novel of permanent importance, that rare sort of book which (in Norman Mailer's felicitous phrase) amounts to "a diversion in the fields of dread." Alice Walker excels at making difficulties for herself and then transcending them. To cite an example: her story begins at about the point that most Greek tragedies reserve for the climax, then becomes by immeasurably small steps a comedy which works its way toward acceptance, serenity and joy. To cite another: her narrative advances entirely by means of letters that are either never delivered or are delivered too late for a response, and most of these are written in a black English that...