At the onset of 'Life, Liberty and the Defense of Dignity', Leon Kass gives a status report of 21th century. He says that 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, creators are confidently amassing their powers and quietly honing their skills. He thinks that for anyone who cares about preserving the humanity, the time has come for paying attention. Leon Kass writes about the limits of science and the limits of life, about what makes people human and gives they human dignity - 'Life, Liberty and the Defense of Dignity'.