At the onset of Life, Liberty and the Defense of Dignity, Leon R. Kass gives us a status report on where we stand today: “Human nature itself lies on the operating table, ready for alteration, for eugenic and psychic ‘enhancement,’ for wholesale redesign. In leading laboratories, academic and industrial, new creators are confidently amassing their powers and quietly honing their skills, while on the street their evangelists are zealously prophesying a posthuman future.” Now, in this brave and searching book, Kass, a trained medical doctor and biochemist, establishes himself as a prophetic voice summoning us to think deeply about the new biomedical technologies threatening to take us back to the future envisioned by Aldous Huxley in Brave New World.