We live in an age where the extinction of languages has become a topic of discussion in many different circles. Opinions on whether the process should be stopped or considered profitable differ widely even in the field of linguistics, let alone in the public domain. A rational attitude presupposes the recognition that a language may constitute a value for some and that value judgements are controlled by more or less outspoken and divergent interests. In the case of a language, interest is taken in its maintenance (or suppression) at all the levels from the individual via the speech community and the scientific community up to mankind. These interests have to be made explicit before the value of a language can be assessed. Ultimately, such an evaluation must even be confronted with the costs that arise in the maintenance of a minority language or in the revitalization of a dying language.