acquired such knowledge incrementally as they made their way through elaborate apprenticeships. Although classical African religions provide institutionalized ways of maintaining or restoring community solidarity, they also allow individuals to influence the cosmic order to advance their own interests. Magic and sorcery both serve this end. From society's standpoint, magic is positive or neutral. On the one hand, magicians try to influence life forces to alter the physical world, perhaps to bring good fortune or a return to health. Sorcerers, on the other hand, are antisocial, using sorcery (or "black magic") to control or consume the vital force of others. Unlike magicians, whose identity is generally known, sorcerers hide their supernatural powers, practicing their nefarious rites in secret. When misfortune occurs, people often suspect that sorcery is at the root of their troubles. They seek counsel from diviners or magicians to identify the responsible party and ways to rectify the situation; if the disruption is deemed to threaten everyone, leaders may act on behalf of the community at large. If discovered, sorcerers are punished. The survival of any society requires that knowledge be passed from one generation to another. In many Chadian societies, this transmission is marked by ritual. Knowledge of the world and its forces is limited to adults; among the predominantly patrilineal societies of Chad, it is further limited to men in particular. Rituals often mark the transition from childhood to adulthood. However, they actively "transform" children into adults, teaching them what adults must know to assume societal responsibilities. Although such rites differ among societies, the Sara yondo may serve as a model of male initiation ceremonies found in Chad. The yondo takes place at a limited number of sites every six or seven years. Boys from different villages, usually accompanied by an elder, gather for the rites, which, before the advent of Western education with its nine-month academic calendar, lasted several months. In recent decades, the yondo has been limited to several weeks between academic years. The yondo and its counterparts among other Chadian societies reinforce male bonds and male authority. Women are not allowed to witness the rite. Their initiated sons and brothers no longer eat with them and go to live in separate houses. Although rites also mark the transition to womanhood in many Chadian societies, such ceremonies are much shorter. Rather than encouraging girls to participate in the larger society, they stress household responsibilities