Should the criterion be physical, like in ancient Sparta? Should it be mental? Should IQ determine one's fate - or social status or wealth? Different answers yield disparate eugenic programs and target dissimilar groups in the population. Aren't eugenic criteria liable to be unduly influenced by fashion and cultural bias? Can we agree on a universal eugenic agenda in a world as ethnically and culturally diverse as ours? If we do get it wrong - and the chances are overwhelming - will we not damage our gene pool irreparably and, with it, the future of our species? And even if many will avoid a slippery slope leading from eugenics to active extermination of "inferior" groups in the general population - can we guarantee that everyone will? How to prevent eugenics from being appropriated by an intrusive, authoritarian, or even murderous state? Modern eugenicists distance themselves from the crude methods adopted at the beginning of the last century by 29 countries, including Germany, The United States, Canada, Switzerland, Austria, Venezuela, Estonia, Argentina, Norway, Denmark, Sweden (until 1976), Brazil, Italy, Greece, and Spain. They talk about free contraceptives for low-IQ women, vasectomies or tubal ligations for criminals, sperm banks with contributions from high achievers, and incentives for college students to procreate. Modern genetic engineering and biotechnology are readily applicable to eugenic projects. Cloning can serve to preserve the genes of the fittest. Embryo selection and prenatal diagnosis of genetically diseased embryos can reduce the number of the unfit. But even these innocuous variants of eugenics fly in the face of liberalism. Inequality, claim the proponents of hereditary amelioration, is genetic, not environmental. All men are created unequal and as much subject to the natural laws of heredity as are cows and bees. Inferior people give birth to inferior offspring and, thus, propagate their inferiority. Even if this were true - which is at best debatable - the question is whether the inferior specimen of our species possess the inalienable right to reproduce? If society is to bear the costs of over-population - social welfare, medical care, daycare centers - then society has the right to regulate procreation. But does it have the right to act discriminately in doing so? Another dilemma is whether we have the moral right - let alone the necessary knowledge - to interfere with natural as well as social and demographic trends. Eugenicists counter that contraception and indiscriminate medicine already do just that. Yet, studies show that the more affluent and educated a population becomes - the less fecund it is. Birth rates throughout the world have dropped dramatically already.