Public controversy over animalbiotechnology is analyzed as a case that illustratestwo broad theoretical approaches for linking science,political or ethical theory, and public policy. Moralpurification proceeds by isolating the social,environmental, animal, and human health impacts ofbiotechnology from each other in terms of discretecategories of moral significance. Each of thesecategories can also be isolated from the sense inwhich biotechnology raises religious or metaphysicalissues. Moral purification yields a comprehensive andsystematic account of normative issues raised bycontroversial science. Hybridization proceeds bytaking concern for all these (...) elements to be a mark ofsound moral character. The advocate of hybridizationinfers that those who employ a strategy ofpurification seek to avoid accountability by dividingissues, and hence are not to be trusted. Lack of trustincreases perceived risk and challenges the legitimacyof government regulations to control social,environmental, and human health risks that areestablished under separate mandate, and administeredby separate agencies.The close alignment between government agencies, theiracademic affines, and the categories of purificationplaces the purified analysis in a favored politicalposition. Legitimation of science-based policy inareas like animal biotechnology becomes problematicbecause the concern of those who would take a hybridapproach (arguably the majority of lay persons) tounderstanding controversial science are excluded.Ironically, this exclusion heightens the perception ofrisk from animal biotechnology. The paper concludeswith a call for procedural approaches to incorporatingthe hybrid view of science‘s moral significance. (shrink)