Preface; 1. Introduction; 2. The pairing force and seniority; 3. The BCS theory; 4. Spontaneous symmetry breaking; 5. Pairing vibrations; 6. Phase transitions; 7. Plastic behaviour of nuclei and other finite systems; 8. Sources of pairing in nuclei; 9. Beyond mean field; 10. Induced interaction; 11. Pairing in exotic nuclei; Appendices; References; Index.