This paper examines the interplay of ethics, social anthropology and epistemology in public health. In the first section, the large range of existing approaches to public health is introduced: public health as a policy-oriented field, as a science, and as a anthropological global project that raises ethical questions. In the second section, a more detailed account is given of the main issues raised by public health by means of locating them in a network of four fundamental dialectical tensions. The first tension concerns the overall aims of public health and disputed definitions of health; the second the legitimacy of the means to achieve the aims of public health; the third the regime of evidence and the framing of public health approaches; and the fourth the power relations built into these public health practices. I suggest that these tensions, in which the polarizations display a variety of forms, are closely related to each other. This leads to the conclusion that in public health, ethical, anthropological and epistemological considerations need to go hand to hand. To understand critically public health issues, the close interactions among the sciences, values and practices need to be taken into account.
Ethics; Public health; Dialectic; Bioethics; Methodology