Why should engineers behave ethically? Often, an answer to this question is sought in the qualification of engineering as a “profession”, and professional or-ganizations have codes of ethics that members should comply with. In many countries however, engineering is organized differently. In this chapter broader conceptions of “professionalism” are explored, inspired by similar evolutions in other occupational areas. A second part questions the idea that professionalism encompasses ethical responsibilities “beyond ordinary morality”. The thesis will be defended that, although there may (...) be specific rules for “professionals”, the philosophical foundation of professional ethics yet rests on ordinary morality. (shrink)