The empirical turn in bioethics has been widely discussed by philosophical medical ethicists and social scientists. The focus of this discussion has been almost exclusively on methodological issues in research, on the admissibility of empirical evidence in rational argument, and on the possible superiority of empirical methods for permitting democratic lay involvement in decision-making. In this paper I consider how the collection of qualitative and quantitative social research evidence plays its part in the construction of social order, and how this (...) creates certain paradoxes for the normative ideal of a public bioethics. The analysis in this paper is based on Foucauldian ideas, and on recent work in the history of the human sciences. The paper closes with some open questions for theoretical work in the sociology and philosophy of bioethics. (shrink)