Note on the front cover. The interplay between well-bounded concepts and gradations is a basic theme in this volume. This theme is reflected in the eagles and African antelopes (elands) on the cover, images inspired by Escher. One might separate out the well-defined images at the top and the bottom as the only real representation of eagles and elands – in parallel to discussion of the only real democracies. Alternatively, the focus could be on gradations among all the images – in parallel to gradations of democracy. These depictions likewise reflect two other basic themes: part–whole relationships and the complex intertwining of concepts. The front cover images were designed by Yellin Yuye Lin.