"Good fish get dull but sex is always fun." So say the Mehinaku people of Brazil. But Thomas Gregor shows that sex brings a supreme ambiguity to the villagers' lives. In their elaborate rituals especially those practiced by the men in their secret societies the Mehinaku give expression to a system of symbols reminiscent of psychosexual neuroses identified by Freud: castration anxiety, Oedipal conflict, fantasies of loss of strength through sex, and a host of others. "If we look carefully," writes Gregor, "we will see reflections of our own sexual nature in the life ways of an Amazonian...