The concept of values builds the ‘umbrella’ of this interdisciplinary volume. But what ‘are’ values? Our volume documents, that values are a contested concept. In this chapter, I want to discuss the polysemic and ambiguous meanings and functions of this term and identify its strengths and weaknesses for public and political discourse. In this way, a more qualified and differentiated reference to values shall be promoted, particularly in the debates about European values. The discussion of values will be achieved using three approaches. First, the concept of values used in the European Values Study (EVS) will be presented. As the EVS does not claim a clear definition of values, a thematic problem outline will, second, reflect the questions, problems, and difficulties occurring in an unreflected usage of this contested term, with a special focus on the relationship between values and religion. Third, an overview of diverse academic definitions and theories of values demonstrates that there is no unique and conclusive definition of this concept. However, this article aims at providing arguments for why exactly the polysemy and ambiguity of the concept of values can be perceived as a strength, if we are aware of the problems and relate them to the results of values research. Thus, we purposely abstain from a final definition of values and hope to inspire further qualified interdisciplinary research, which is a desideratum that has become visible in our project.