1. Preface; 2. A. Introduction; 3. I. Introduction; 4. 1. What is naturalness?; 5. 2. Inflection and word formation; 6. 3. Towards a theory of morphological naturalness; 7. 4. The structure of a theory of naturalness; 8. 5. Evidence for naturalness; 9. 6. The semiotic framework of natural morphology; 10. 7. Divergences and convergences among proponents of natural approaches to morphology; 11. Notes; 12. B. Naturalness in Inflection; 13. I. System-independent morphological naturalness (by Mayerthaler, Willi); 14. 0. Introduction; 15. 1. Universal grammar and markedness; 16. 2. Preference theories; 17. 3. Some other prerequisites of theoretical morphology; 18. 4. Principles of morphological markedness theory; 19. 5. What is a 'theory'?; 20. 6. Appendix on attractors in catastrophe theory; 21. Notes; 22. II. System-dependent morphological naturalness in inflection (by Wurzel, Wolfgang Ullrich); 23. 0. Naturalness, morphology and language system; 24. 1. System-dependent naturalness I: System-congruity; 25. 2. System-dependent naturalness II: Stability of inflectional classes; 26. 3. System-congruity and class-stability: Productivity in inflectional morphology; 27. 4. Naturalness principles of inflectional morphology; 28. Notes; 29. C. Naturalness in Word Formation; 30. I. Word formation as part of natural morphology (by Dressler, Wolfgang U.); 31. 1. Introduction; 32. 2. Iconicity in word formation; 33. 3. Indexicality in word formation; 34. 4. The scale of (bi)uniqueness in word formation; 35. 5. Signans shapes adequate for motivation in word formation; 36. 6. Typological adequacy of word formation rules; 37. 7. System adequacy (congruity) of word formation rules; 38. 8. Inflection vs. derivation again; 39. Notes; 40. II. Productivity and diachronic change in morphology (by Panagl, Oswald); 41. 0. Introduction; 42. 1. Interpretations of productivity; 43. 2. Vedic root-nouns and Ancient Greek diminutives; 44. 3. Semantic predictability (transparency); 45. 4. Transition from word formation into inflection; 46. 5. Hierarchy of productivity in types of word formation; 47. 6. Conclusion on productivity in corpus languages: The Latine Supine in -(t)um - a Case Study of Categorial Change; 48. 7. From derivational to inflectional morphology; 49. 8. Reasons for loss of productivity; 50. 9. Indo-European cognates; 51. Notes; 52. Abbreviations; 53. General bibliography; 54. Subject index