Book excerpt: This book grapples with the moral meaning of the new biomedical technologies now threatening to take us back to the future envisioned by Aldous Huxley in "Brave New World". In a series of meditations on cloning, embryo research, the sale of organs, and the assault on mortality itself, Kass questions the wisdom of trying to break down the natural boundaries given us and to remake the human body into an instrument of our will.