Introduction: Conceptual issues in quantum field theory; Part I. Philosophers' Interests in Quantum Field Theory: 1. Why are we philosophers interested in quantum field theory; 2. Quantum field theory and the philosopher; Part II. Three Approaches to the Foundations of Quantum Field Theory: 3. The usefulness of a general theory of quantized fields; 4. Effective field theory in condensed matter physics; 5. The triumph and limitations of quantum field theory; 6. Comments; Discussions; Part III. Does Quantum Field Theory Need a Foundation: 7. Does quantum field theory need a foundation?; Part IV. Mathematics, Statistical Mechanics and Quantum Field Theory: 8. Renormalization group theory: its basis and formulation in statistical physics; 9. Where does quantum field theory fit into the big picture?; 10. The unreasonable effectiveness of quantum field theory; 11. Comment: the quantum field theory of physics and of mathematics; Part V. Quantum Field Theory and Spacetime: Introduction; 12. Quantum field theory and spacetime: formalism and reality; 13. Quantum field theory of geometry; 14. 'Localization' in quantum field theory: how much of QFT is compatible with what we know about spacetime; 15. Comments; VI. 16. What is quantum field theory and what did we think it was?; 17. Comments; Discussions; Part VII.Renormalization Group: 18. What is fundamental physics? A renormalization group perspective; 19. Renormalization group: an interesting yet puzzling idea; Part VIII. Non-Abelian Gauge Theory: 20. Gauge fields, gravity and Bohm's theory; 21. Is the Aharonov-Bohm effect local?; Discussions; Part IX. The Ontology of Particles or Fields: 22. The ineliminable classical face of quantum field theory; 23. The logic of quanta; 24. Do Feynman diagrams endorse a particle ontology?; 25. On the ontology of QFT; Part X. Panel Discussion.