Part I: Science, Social Science, Economics -- 1. Introduction -- 2. The Character of Science -- 3. Genesis and Development of Economics and Sociology -- Part II: Economics -- 4. Orthodox Microeconomics -- 5. Orthodox Macroeconomics -- 6. Evolution and Entrepreneurship, an Evolutionary and an Austrian View -- 7. Radical Economics -- 8. Post-Keynesian Economics -- 9. Social Economics -- Part III: Psychology for Economists -- 10. Psychology for Economists -- Part IV: Sociology for Economists -- 11. Macro and Micro Approaches in Sociology -- 12. The Historical Approach in Sociology -- 13. Multidisciplinary Sociology and The Social World -- Part V: Towards an Integration of the Three Worlds -- 14. The Integration of the Three Worlds -- 15. Applications of the MDE World Approach -- Part VI: Conclusions -- 16. Conclusions -- Appendices -- A. The Logical World -- B. Kant for Economists -- C. Jung for Economists -- D. Adam Smith as the Founding Father of Multidisciplinary Economics.