The acausal character of Werner Heisenberg’s “Quantum-theoretical Reinterpretation of Kinematic and Mechanical Relationships” was implicit in his approach. The result of Heisenberg’s continued struggle with the problem through the winter of 1926/27 was his uncertainty principle paper, which he titled “On the Intuitive Content of the Quantum-Theoretic Kinematics and Mechanics.” The properties and behavior of the “entities of the world,” the as yet undiscovered laws of atomic structure and of the quantum, “may be true laws of governance"—by which Eddington did not mean that these “transcendental” laws will be deterministic. The Solvay Congress of October 1927 was an important educational experience which opened the eyes of the participating British physicists to the inescapably acausal character of the quantum mechanics. In striking contrast with Germany, the intellectual mood in immediate post-war Britain contained relatively little irrationalism. Germany’s completely unexpected military and industrial collapse at the end of 1918 brought an immediate and extreme public reaction against the industrial-scientific idols.