Since the 18th century, the term idealism has been used to characterize philosophical theories that champion the priority of a mental reality vis-à-vis the material external world. But the term has quite different connotations in different languages, which arise from differering understandings of the term idea. In the German-speaking world, idea stands in the Platonic tradition (Platonism), usually in the sense of a general concept of something that exists outside the in…