Beauchamp and Childress (1994) elaborated an approach to bioethical deliberations based on four universalistic principles. This framework of ‘principlism’ has been criticized from within biomedical ethics as insufficient and problematic. However, this article considers a more radical sociological critique by John Evans (2002) that rejects the entire approach of defining ‘principles’ a priori. This sociological critique is based on classical sociologist Max Weber's (1925) distinction between instrumental (‘thin’) and substantive (‘thick’) rationality. As an exploratory assessment of Evans' critique, his conceptualization (...) of ‘thin’ versus ‘thick’ rationalization is applied to a large sample of Anglo-American press coverage (n = 5126) of the bioethical controversy surrounding therapeutic cloning. Given the role of mainstream news media as a key arena for the discursive framing of biomedical research and its ethical implications, the findings raise important questions about principlism and the mediation of bioethical debates on issues such as therapeutic cloning. (shrink)