 One year before his death Ludwig, together with Gérald Thurler, published a revised and simplified edition of Ludwig (1990) with the title “A new foundation of physical theories”. This work cannot be used as a textbook but it is a remarkable document of the central themes of his approach and his general views on physics. The book clearly shows that Ludwig’s main concern is about scientific realism, i.e., about the question of how hypothetical objects and relations occurring within a successful theory acquire the status of physical reality. Entities which cannot claim this status are dubbed as “fairy tales” throughout the book. Examples of fairy tales in quantum theory are hidden variables and, perhaps surprising for some readers, also the single-particle-state interpretation (in contrast to the ensemble interpretation fostered by Ludwig). 