1 Chiral Symmetry and the BAG Model: A New Starting Point for Nuclear Physics -- 1. Introduction -- 2. The Basic Bag Model -- 3. Hadronic Properties in the MIT Bag Model -- 4. Chiral Symmetry -- 5. Bag Models with Chiral Symmetry -- 6. Applications of the Cloudy Bag Model -- 7. Towards a New View of Nuclear Physics -- 8. Conclusion -- Acknowledgements -- Appendix I -- References -- 2 The Interacting Boson Model -- 1. Introduction -- 2. The Interacting Boson Model-1 -- 3. Geometric Properties of the Interacting Boson Model-1 -- 4. The Interacting Boson Model-2 -- 5. Microscopic Description of Interacting Bosons -- 6. Conclusions -- Acknowledgements -- References -- 3 High-Energy Nuclear Collisions -- 1. Introduction -- 2. Theoretical Tools -- 3. Elements of the Reaction Mechanism -- 4. Toward the Physics of Dense Nuclear Matter -- 5. Summary and Outlook -- Acknowledgments -- Appendix: Definition of Common Variables -- References.