  Some philosophers think they can be distinguished, and they have explored the desirability of a “liberal” or “new” as opposed to an “authoritarian” or “old” eugenics (Agar 2004). Liberal eugenics would be based upon prospective parents’ free choice, pluralist values, and up-to-date scientific understanding of genomic science and technology. Furthermore, advocates of liberal eugenics aim to be sensitive to the effects of some problematic but deeply entrenched social problems (e.g., racism, sexism, heterosexism) on individual choice. Authoritarian eugenics programs, in contrast, were coercive state programs designed to promote social goods, and were based on problematic scientific assumptions about hereditability. Liberal eugenicists point to significant developments in our understanding of genomic science to help distinguish contemporary liberal eugenics from its problematic predecessors. Indeed, scientific advances of the last several decades – years that include the advent of in vitro fertilization (IVF), the funding and completion of the Human Genome Project, creation of the National Human Genome Research Institute (NHGRI), and expansions of pre-implantation screening, prenatal testing panels, as well as development of genome editing – provide not only more precise understandings of genes and their role in shaping phenotypes and gene-environment interactions, but also a multitude of possibilities for intervention in the process of reproduction. How ought we to use this new knowledge and capacities? This entry proceeds as follows. It first offers a short history of the eugenics movement. The second section presents some of the main arguments that attempt to define and defend a new or liberal eugenics. The last section covers a variety of critiques of those arguments.