Book excerpt: Uncovering the wealth of traditional African knowledge and techniques has direct implications for the future development of the continent. This book is written against the background of the tragedy that most Africans are profoundly ignorant of the achievements of the past, let alone the traditions that are still upheld today. It is an exploration and analysis of Africa's historical roots, and the editor is one of Africa's most distinguished philosophers. Rich in detailed and original field research, the volume covers a wide variety of topics, from the probability theory of cowry shell diviners, to hydrology and rainmaking, and the links between sorcery and psychosomatic medicine. Chapters include the use of number systems, ingredients used in pharmaceutical practice, and the mysterious phenomena of foreign objects projected into human bodies.