The results of a mathematical colloquium published by Karl Menger and his colleagues (including Kurt Gödel) are among the most important source works in the history of science and ideas during the interwar period, featuring groundbreaking contributions from Menger, Gödel, Tarski, Wald, John von Neumann, and many others. This volume presents the content for the first time in a collected form. Nobel laureate Gerard Debreu wrote the introduction, while the comments were authored by the logician and Gödel biographer John Dawson Jr., the topologist Ryszard Engelking, and the economic theorist Werner Hildenbrand. Additionally, the volume includes a biographical essay on Karl Menger as well as an overview of the key topological and geometrical works of the colloquium written by Menger.