“There are concepts that are suffering from their own success. What had once been the label of a productively irritating idea might represent now something that has turned to be part of the usual agenda. ‘Sustainability’ is one example.‘Transdisciplinarity’ another. Hence, it is not an easy task, first, not to come too late to reconsidering this concept; second, to achieve to say something new; and, third, to combine structure and content: writing on transdisciplinarity in a transdisciplinary way. This volume is meeting this three-fold task—with a highly prominent line-up, truly new perspectives on still pertinent challenges, and a very well designed structure of seminal papers and equally programmatic replies.”