I Carl Friedrich von Weizsäcker and His Role in the Physics of the 20th Century -- Carl Friedrich von Weizsäcker and The Kaiser Wilhelm/Max Planck Society -- The Role of the Physicist in the Nuclear Age -- "The Atomic Bomb Reveals the Political Responsibility of Science" -- On the Unfathomableness of Consciousness by Consciousness -- II Carl Friedrich von Weizsäcker's Contributions to Nuclear and Astrophysics and Their Impact on the Development of Physics -- Introduction: From the Atomic Nucleus to Cosmic Vortex Systems -- The Origins of Nuclear Physics and Carl Friedrich von Weizsäcker's Semi-Empirical Mass Formula -- Thermonuclear Processes in Stars and Stellar Neutrinos -- Comets: Fascinating Cosmic Objects -- The Spectrum of Turbulence -- From Dust Disks to Planetary Systems -- III The Unity of Nature and the Nature of Time -- Science and Its Relation to Nature in C.F. von Weizsäcker's Natural Philosophy -- C.F. von Weizsäcker's Philosophy of Science and the Nature of Time -- What Is Missing? - The Fundamental Role of Time in C.F. von Weizsäcker's Conception of Physics and Some Insights from Modern Neuroscience -- Irreversibility via Semichaos -- Remarks on Fractional Time -- The Dynamics of Modelling -- IV The Structure of Quantum Theory and Its Interpretation -- An Introduction to Carl Friedrich von Weizsäcker's Program for a Reconstruction of Quantum Theory -- Interpreting Quantum Mechanics - in the Light of Quantum Logic -- On the Interpretation of Quantum Theory - from Copenhagen to the Present Day -- Epistemic and Ontic Quantum Realities -- Information and Fundamental Elements of the Structure of Quantum Theory -- Multiple Quantization in Fock Space -- V The Ur-Hypothesis and Its Implications for Particle Physics and Cosmology -- The Ur-Hypothesis -- The Momentum Eigenstates and the Lorentz-Invariant State -- C.F. von Weizsäcker's Reconstruction of Physics: Yesterday, Today, Tomorrow -- The Operational Structure of Spacetime -- Ur Theory and Space-Time Structure -- Weizsäcker's Ur Theory - A Cosmological Point of View -- Ur Theory and Cosmological Phase Transition -- Phase Transitions in an Expanding Universe: Paul Roman's Models and Some Remarks on Entropy -- C. F. von Weizsäcker: Biographical Data and Selected Bibliography in Physics -- The Authors.