Human actions occur at the confluence of circumstances in which the right way to act needs to be discerned. Ethics lies in the field of practical knowledge, knowledge of what is contingent. Ethics is the domain of moral judgements or value judgements. The disenchantment of the contemporary world has its counterpart in the effort to restore interest in ethics. Relations between public health and human rights are mainly of three orders: striking a balance between the collective good and individual rights; methods and techniques to identify human rights violations and assess their negative impact; and the link between the protection of human rights and health promotion. The links between ethics and epidemiology go beyond ethical aspects related to human research. They are broken down into policy commitments, practices in health services and knowledge generation.