Introduction; Part I.: Foundations; Chapter 1. Power; Chapter 2. Economic Content of the Separation of Powers Theories?; Chapter 3. Political Content of Antitrust from a Historical Perspective; Chapter 4. Political Content of Antitrust in the Digital Era; Part II.: Interactions; Chapter 5. Separation of Powers in Antitrust; Chapter 6. Antitrust in Separation of Powers; Part III.: Toward a New Separation of Powers; Chapter 7. General Issues; Chapter 8. Promises and Shortcomings of Recent or Proposed Legislation; Chapter 9. New Politico-Economic Axes of the Separation of Powers; Chapter 10. New Institutional and Individual Axes of the Separation of Powers; Conclusion.