Many philosophers and sociologists of science have tried to understand the profound changes that have occurred in science, engineering and technology. In the first part of this paper, I present the work of one such scholar: Jerome Ravetz who, in collaboration with Silvio Funtowicz, has characterised what he calls "postnormal science". The purpose of this theoretical part of the paper is to describe what characterises contemporary science and to formulate which competencies contemporary scientists need to act ethically. In the second part of the paper, I present and analyse the course "Philosophy of Science and Ethics" that I have taught since 2005 to biochemistry, chemistry and nanotechnology students at the University of Copenhagen. The course is intended to prepare its participants for postnormal knowledge production that is scientific work that is embedded in a societal context characterised by uncertainty and conflicting values systems. With this in mind, I analyse the course by relating its content to the concepts that describe postnormal science, and I discuss how the course develops the ethics competencies that contemporary scientists need to work in postnormal science. I will also briefly discuss the relevance of the course for engineering students. (Contains 4 notes.)