Contents -- Notes on Contributors -- 1. Quantum Gravity Meets Structuralism: Interweaving Relations in the Foundations of Physics -- 1.1 Quantum Gravity: Background, Concepts, and Methods -- 1.1.1 The Hole Argument and Spacetime Ontology -- 1.1.2 Gauging the Hole Argument -- 1.1.3 Enter Quantum Gravity -- 1.1.4 Categorizing the Manifold Methods -- 1.1.5 What's Wrong with Background-Dependent Methods? -- 1.1.6 What's Right about Background-Independent Methods? -- 1.1.7 Background Independence and Structuralism -- 1.2 Structuralism and Structural Realism -- 1.2.1 Motivating Structuralism -- 1.2.2 What is Structuralism? -- 1.2.3 …and Where Does it Come from? -- 1.2.4 Structural Realism -- 2. Structural Realism and Quantum Gravity -- 2.1 Structural Realism -- 2.2 Physical Reality of Spacetime and Quantum Fields -- 2.3 Quantum Gravity -- 3. Structure, Individuality, and Quantum Gravity -- 3.1 What is Structural Realism? -- 3.2 Structure and Individuality -- 3.3 Effective Field Theory and Asymptotic Quantization -- 3.4 String Theory -- 3.5 Quantum General Relativity: Some Preliminary Problems -- 3.5.1 States or Processes: Which is Primary? -- 3.5.2 Formalism and Measurability -- 3.6 Canonical Quantization (Loop Quantum Gravity) -- 3.7 The Causal Set (Causet) Approach -- 3.8 What Structures to Quantize? -- 4. Points, Particles, and Structural Realism -- 4.1 What is Structural Realism? -- 4.2 Underdetermination -- 4.3 What is Ontic Structural Realism? -- 4.4 Objects -- 4.5 Sophisticated Substantivalism -- 4.6 Stachel's Generalized Hole Argument for Sets -- 4.7 Stachel on Identical Particles -- 4.8 Identical Particles and Identity over Time -- 4.9 Two Morals for Quantum Gravity -- 5. Holism and Structuralism in Classical and Quantum General Relativity -- 5.1 Introduction: Two Strands of Philosophy of Physics that Ought to be Brought together.

5.2 Many 'Realisms' or One? -- 5.2.1 What, Exactly, is a Physical Structure? -- 5.3 A Case Study: The Holistic and Structural Nature of General-Relativistic Spacetime in a Class of Models of GR -- 5.3.1 The Hole Argument and its Consequences -- 5.3.2 The Dynamical Individuation of Point-Events -- 5.4 Developing Hints for the Quantum Gravity Programme -- 5.5 Structural Spacetime Realism -- 5.5.1 The Nature of Point-Events and Overcoming the Substantivalism/Relationism Debate -- 6. Time and Structure in Canonical Gravity -- 6.1 Introduction -- 6.2 Constraints, Gauge, and Holes -- 6.2.1 Hamiltonian Systems: Constraints and Gauge -- 6.2.2 Constraints and Gauge in General Relativity -- 6.2.3 Interpreting Gauge Theories -- 6.3 What is the Problem of Time? -- 6.4 A Snapshot of the Philosophical Debate -- 6.4.1 Time Series from A to D -- 6.4.2 Maudlin versus Earman -- 6.5 Catalogue of Responses -- 6.5.1 Timefull Stratagems -- 6.5.2 Timeless Stratagems -- 6.6 Enter Structuralism -- 6.7 Conclusion -- 7. The Case for Background Independence -- 7.1 Introduction -- 7.2 A Brief History of Relational Time -- 7.3 What Physicists Mean When We Talk about Relational Space and Time -- 7.4 General Relativity as a Partly Relational Theory -- 7.4.1 The Problem of Time and Related Issues -- 7.5 Relationalism and the Search for the Quantum Theory of Gravity -- 7.5.1 The Causal Set Theory -- 7.5.2 Loop Quantum Gravity -- 7.5.3 Causal Dynamical Triangulation Models -- 7.5.4 Background-Independent Approaches to String and M Theory -- 7.6 Relationalism and Reductionism -- 7.6.1 The Challenge of the String Theory Landscape -- 7.7 A Relational Approach to the Problems of Unification and Determination of the Standard Model Parameters -- 7.8 Relationalism and Natural Selection -- 7.9 What about the Cosmological Constant Problem?.

7.10 The Issue of Extending Quantum Theory to Cosmology -- 7.10.1 Relational Approaches to Quantum Cosmology -- 7.10.2 Relational Approaches to Going beyond Quantum Theory -- 7.11 Conclusions -- 8. Quantum Quandaries: A Category-Theoretic Perspective -- 8.1 Introduction -- 8.2 Lessons from Topological Quantum Field Theory -- 8.3 The * -Category of Hilbert Spaces -- 8.4 The Monoidal Category of Hilbert Spaces -- 8.5 Conclusions -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- U -- V -- W -- Y.