The Kamasutra, composed in the third century CE, is the world's most famous textbook of erotic love. There is nothing remotely like it even today, and for its time it was astonishingly sophisticated. Yet it is all but ignored as a serious work in its country of origin-sometimes taken as a matter of national shame rather than pride - and in the rest of the world it is a source of amused amazement and inspires magazine articles that offer "mattress-quaking...