An engaging, enlightening "biography" of the ancient Hindu manuscript that became the world's most famous sex manual The "Kamasutra "is one of the world's best-known yet least-understood texts, its title instantly familiar but its actual contents widely misconstrued. In the popular imagination, it is a work of practical pornography, a how-to guide of absurdly acrobatic sexual techniques. Yet the book began its long life in third-century India as something...