About the often underestimated necessity of libraries in the 21st century. Users flock in droves to the reading rooms and group study areas of academic libraries. However, their role seems to become increasingly unclear in the age of the internet: Is not the most important information already available online? What function does the library serve then - is it a learning center? A logistics hub for information? A social space? Is sharing and exchanging what defines the essence of the library? This book argues that academic libraries have a primary responsibility, which has existed since the earliest days of Nineveh and Alexandria: the responsibility for the availability of knowledge. Their purpose is to provide information about the current state of understanding. Realizing this idea becomes a complex challenge for each individual library. Libraries must collaborate much more closely than before. The concept of the library only works within the system of libraries. However, in Germany, libraries find themselves trapped in the federalism dilemma with their unfinished communal tasks. For the idea of the library to come to fruition, courageous library policies are needed. The former director of the Duchess Anna Amalia Library reflects on the history and present of libraries and questions their significance for the future.