Part I. Papers and Book Chapters, 1948-70: 1. The concept of intelligibility in modern physics (1948); 2. Physics and ontology (1954); 3. Determinism and quantum mechanics (1954); 4. A remark about von Neumann's proof (1956); 5. Complementarity (1958); 6. Niels Bohr's interpretation of the quantum theory (1961); 7. Problems of microphysics (1962); 8. About conservative traits in the sciences and especially in quantum theory, and their elimination (1963); 9. Problems of microphysics (1964); 10. Peculiarity and change in physical knowledge (1965); 11. Dialectical materialism and the quantum theory (1966); 12. Remarks about the application of non-classical logics in quantum theory (1966); 13. On the possibility of a perpetuum mobile of the second kind (1966); 14. In defense of classical physics (1970); Part II. Reviews and Comments, 1957-67: 15. Review of Alfred Landé, Foundations of Quantum-Mechanics: A Study in Continuity and Symmetry (1957); 16. Discussions with Léon Rosenfeld and David Bohm (1957); 17. Review of John von Neumann, Mathematical Foundations of Quantum Mechanics (1958); 18. Review of Hans Reichenbach, The Direction of Time (1959); 19. Professor Landé on the reduction of the wave packet (1960); 20. Comments on Grünbaum's 'Law and Convention in Physical Theory' (1960); 21. Comment on Hill's 'Quantum Physics and Relativity Theory' (1960); 22. Review of Norwood R. Hanson, The Concept of the Positron: A Philosophical Analysis (1964); 23. Review of Hans Reichenbach, Philosophic Foundations of Quantum Mechanics (1967); Part III. Encyclopaedia Entries, 1958-67: 24. Natural philosophy (1958); 25. Philosophical problems of quantum theory (1964); 26. Ludwig Boltzmann, 1844-1906 (1967); 27. Werner Heisenberg (1967); 28. Max Planck, 1858-1947 (1967); 29. Erwin Schrödinger, 1887-1961 (1967).